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a. Set the camshaft timing relatively close using the pinning method (using a 15/64 drill bit as a pin). b. Use Cylinder #1 for drivers side bank and Cylinder #6 for passenger side bank. c. Install Timing Chain temporary manual tensioners.
Use Jeffvette Billet Aluminum Camshaft Retainers which will remain in place after camshaft timing is complete.
To start the cam timing process rotate the crankshaft to the 51 deg mark BTDC on the front pulley aligned with "0" on timing plate (degree wheel installed on front crankshaft pulley). Keep in mind that this discussion is for the Drivers side Heads. For the Passenger side Heads use cylinder number 6 instead of cylinder number 1 when setting the camshaft timing using the degree wheel with the method of finding maximum cam lift. TDC for cylinder number 6 will be 360 deg from cylinder number 1. 114 deg ATDC IN and 110 deg BTDC EX will be related to the TDC of cylinder number 6..
Install all cams in the neutral position (no lifters being compressed) using the Billet Aluminum (oiled) Camshaft Retainers with Torx bolts tightened (89 in-lbs) with loctite 262.
Looking at the front of the engine toward the rear so clockwise is normal engine rotation from that perspective.
Rotate exhaust camshafts to insert a 15/64 drill bit as a pin into the pinning hole in exhaust camshafts (hole in front camshaft Retainer). Pin counterclockwise one pin hole to allow for 110 deg BTDC EX. Rotate intake camshafts to insert 15/64 drill bit as a pin into the pinning hole in intake camshafts (hole in front camshaft Retainer) as that should be close to 114 deg ATDC IN.
The Pinning Method will get you close to these timing numbers (110 deg BTDC EX and 114 deg ATDC IN). Fine tuning the camshaft timing for a ported engine (for example), use the degree wheel and a dial gauge on the lifters for the additional fine camshaft timing adjustments. See step 5c of LT5 Camshaft Timing Additional Tricks
Rotate the camshaft sprockets counterclockwise against the chain, and then set vernier plate pin in "next" hole clockwise where the pin might fit. Then tighten a bit the camshaft bolts such that the "flat" of the camshaft is counterclockwise tight against the flat of the vernier plate which was rotated clockwise (holding a 19 mm box wrench on the rear end of the camshaft).
That degree wheel provided by bdw18_123 was used.
I reduced the image size (actual printed diameter) to 7.08 inches when printing and glued it on the front pully with my 51 deg BTDC, 114 deg ATDC, 110 deg BTDC, and TDC marked on the wheel. I cut a 4 inch hole in the center of the degree wheel print out before I glued it so I could get my 13/16 inch wrench on the front pully bolt.
I used that degree wheel to place marks on the inside of the front pully.
I could then align degree wheel marks with the factory timing plate Advance Marks and TDC "O" Mark attached to the front of the engine (drivers side) almost touching the inside of the front pully. Making sure I was always on #1 cylinder compression stroke.
2. Determine TDC on the Harmonic Balancer.
The first thing to do is verify TDC. Always rotate the crankshaft clockwise looking at front of engine.
I checked my mark on the Harmonic Balancer for TDC. I set up a dial indicator on cylinder number one. The piston moved .029 inch before and .029 inch after TDC which was exactly 10 deg before and 10 deg after my mark on the front pully. My TDC mark on front pully is right on the money.
3. Camshaft Sprocket and Venier Plate.
There are 20 teeth on the cam sprocket or 18 degrees per tooth. There are 14 holes in sprocket or 25.7 degrees if you rotate vernier plate without removing pin from hole in vernier plate and pin next hole in sprocket (15 holes in vernier plate and 14 holes in sprocket). There is 1.6 deg on the camshaft sprocket if you rotate vernier washer to align with next pin hole in sprocket (360/15/15). So if you went 11 holes that would be like one tooth on camshaft sprocket or 17.6 degrees on the camshaft sprocket retard or advance. The smallest amount of retard or advance you could set would be 1.6 deg on the camshaft sprocket by pinning next aligned holes (3.2 deg on the Harmonic Balancer).
Marc Haibeck suggests there is about 3 deg of play (6 deg measured at the crankshaft) between the sprocket timing plate flat (vernier plate) and camshaft flat (90'-92'). This is reduced to 1.5 deg (3 deg measured at the crankshaft) on 93s' (having double flats). As one tightens the camshaft bolt you have to watch not to turn the camshaft in the timing plate (vernier plate). It helps to hold a 19 mm open end wrench on the rear of each cam during tightening of the camshaft bolt.
This 3 deg of play (at the camshaft) actually allows you to set the camshaft timing at any angle within the 1.6 deg (at the camshaft) allowed by the pin holes in the vernier plate and sprocket.
Marc Haibeck has upgraded his article "Timing the LT5 Camshafts" to .pdf on his website Timing LT5 Camshafts
I will use a similar setup with the dial indicator on the intake and exhaust primary lifters for cylinder number one (left Head) and cylinder number six (right Head) to determine crankshaft angle at camshaft maximum lift. I will first mark 114 ATDC and 110 BTDC on the Harmonic Balancer and set dial gauge up on lifters to verify intakes at 114 deg ATDC and exhaust at 110 deg BTDC on number one cylinder.
Marc suggests to have a broad torque and power range (3000 to 7000 rpm) use Intake 114 ATDC and Exhaust 110 BTDC. 114/114 is nice when trying to tame idle roughness out of a engine having modified Camshafts.
What you want is equal lifter depression before and after max lifter depression noting the crankshaft rotation degrees (degree wheel set up on front of crankshaft pully) before and after max lift set up on (No. 6 cylinder passsenger side and No. 1 cylinder drivers side). For Intake example you might see equal lifter depression at 104 deg ATDC and 124 deg ATDC and splitting the difference would be 114 deg ATDC. You do the equal lifter depression "trick" because it is almost impossible to see max lifter depression using a dial gauge within say 5 deg either way as the cam lobe rotates over the flat.
Marc Haibeck suggests positioning the cam at .010" before top of lift and .010" after top of lift point where .001" change in lift is about 1 degree of cam rotation.
If I am off on the camshaft timing, I will adjust vernier plate and/or re-pin sprocket and re-snug the camshaft bolt and verify again. Once I have the correct camshaft timing I will final tighten the camshaft bolts without moving the camshaft. See step 5c of LT5 Camshaft Timing Additional Tricks
If I am OK (110 deg BTDC EX and 114 deg ATDC IN), I will tighten the camshaft bolts without moving camshaft (an extremely important step since Marc has seen significant evidence of camshaft shifting after the camshaft bolt is torqued on many engines). I will re-intall the aluminum CNC camshaft retainers installed with cardboard spacer to take out slop and to hold camshaft when I tighten front camshaft bolt (using 19 mm box wrench on the other end of camshaft).
I will Use Loctite 262 on the camshaft bolt, and lubricate both sides of the washer. Tighten to 19 ft lbs and then mark a straight line and then proceed to tighten (Stretch) the bolt (Marc's Camshaft Bolts) another 80-85 degrees (while holding a 19 mm box wrench on the other end of the camshaft).
After the camshaft timing is set, I will remove the manual chain tensioners and install the factory hydraulic chain tensioners set in travel position. I will give the chain tensioners a tap to activate each tensioner.
1. First make sure of TDC
If you want to make sure of the TDC marks on the Harmonic Balancer, you can install a dial gauge to determine when piston #1 is TDC to determine TDC easy enough engine in car and can then mark harmonic balancer and use degree tab bracket easy enough engine in car. The Tab has marks 25 deg Before and 5 deg After TDC. Always rotate the crankshaft clockwise looking at front of engine.The Tab has marks 25 deg Before and 5 deg After TDC (A total of 30 deg). You can use the marks on the Timing Tab to mark your Harmonic Balancer. Mark 110 deg BTDC by rotating the Harmonic Balancer 3 complete Tabs (90 deg) + 20 deg Counter Clockwise and mark. Mark 114 deg ATDC by rotating the Harmonic Balancer Clockwise 3 complete Tabs (90 deg) + 24 deg and mark.
Ben's Trick Marking the cam journal and sprocket (just behind the sprocket) helps considerably keeping track of where you are in the camshaft timing process as Ben suggested (Ben's photo below). You know right away if things have moved on you.
Another Ben trick is to use the old camshaft bolts (snugged up to prevent the camshafts from popping forward or backward) during the timing process and then with the camshaft in a position where it will not pop or rotate backward or forward (best achieved with one set of valves at maximum opening), switch to the new camshaft bolts (with red loctite) for final camshaft bolt tightening.
4. Using a Dial Gauge.
A third trick is to use Lee's Harbor Freight Flexible Arm to hold the dial gage when measuring lifter movement. Harbor Freight Flesible Arm
5. Installation of New Camshaft Bolts.
After you degrease the new camshaft bolts, use plenty of red (262) Loctite on the camshaft bolts.
a. Jerry's Camshaft Bolts ---- 80 ft-lbs torque b. Marc's Camshaft Bolts -----18 ft-lbs + 80 deg rotation of camshaft bolt.
6. Venier plate movement.
a. For a (90-92 LT5) there is 6 deg of crankshaft play when the camshaft flat rotates 3 deg against the flat of the venier plate (flat to flat). b. It has also been calculated that each pin hole advance or retard moves the camshaft 1.6 deg (3.2 deg at crankshaft). c.Set up with the camshaft venier plate rotated against the camshaft flat (clockwise looking at front of engine).Forget about the 6 deg of crankshaft play (3 deg in the venier plate flat to flat) relative to camshaft movement for the moment.
7. Checking Actual Valve Maximum Opening Degrees.
Check actual valve max opening (shooting for 114 deg ATDC INTAKE for example) using equal Lifter movement before and after max valve opening. a. Look for .015 less than maximum lifter movement either side of maximum valve opening as you rotate the crankshaft (clockwise looking at front of engine) through max valve lift. b. If you have maximum valve opening at 112 deg ATDC (2 deg off) you have to rotate the camshaft and venier plate clockwise with respect to the camshaft sprocket one peg hole or 3.2 deg crankshaft rotation which would put you at 115.2 deg ATDC next check.
[B]c. The venier plate could now be rotated counterclockwise looking at front of engine 3 deg within the total play in the venier plate by locking the venier plate tight in the counterclockwise direction against the camshaft. In this case keep the venier plate locked in the clockwise direction (looking at front of engine) against the camshaft to eliminate this larger potential adjustment/play consideration which would amount to 6 deg of crankshaft rotation.
8. Tightening the Camshaft Bolt.
It is difficult to tighten the camshaft venier plate down on the camshaft with the flat of the venier plate somewhere within the 3 deg of play (6 deg of crankshaft rotation) where the venier plate can rotate back and forth on the camshaft. a. The Trick is to lock the venier plate flat in the most clockwise direction (clockwise looking at front of engine) tight against the flat of the camshaft.
Notes:
1. The worst you could be off (INTAKE Camshaft 114 deg ATDC example) would be 1.6 deg crankshaft rotation if you were at or greater than 115.6 deg ATDC or at or less than 112.4 deg ATDC first check. Just leave well enough alone (any degrees between 115.6 and 112.4 deg ATDC). [B]Either is very close and within measurement error (determining maximum lifter lift by any method within 1 deg is very difficult) of 114 deg ATDC desired INTAKE camshaft timing or 110 deg BTDC EXHAUST camshaft timing.
2. Keeping the venier plate locked in the clockwise direction against the camshaft flat eliminates the venier plate rotation when tightening the camshaft bolt while holding the camshaft from rotating on the other end with a box wrench.
3. This technique simplifies the adjustment and assures the camshaft sprocket venier plate flat is always against the flat of the camshaft rotating clockwise looking at front of engine (less chance for the venier plate to rotate and venier plate/camshaft flats to move relative to one another during or after camshaft bolt tightening).
LT5 Timing Diagrams and Timing Chain Effective Lengths
LT5 Timing Diagrams and Timing Chain Effective Lengths
1. Timing Diagrams.
The Timing Chain Effective Lengths depends on Timing Chain Tightness and Chain Guide Wear...theory under development testing as we speak.
2. Timing Chain Effective Lengths.
The crankshaft rotates clockwise looking at front of engine. The Timing Chain Tensioners are located on the bottom (passenger side) chain before Camshaft Sprockets and on the top (drivers side) chain before Camshaft Sprockets. The chain between and after the Camshaft Sprockets returning to the timing chain Idler Sprocket is normally relatively tight. That section of the Timing Chain remains relatively tight as long as the crankshaft is rotated in a normal direction and as long as cams do not push back (lifters pushing the camshafts clockwise). Timing chain Effective Lengths are related directly to timing chain tightness and Timing Chain paths as directed by the Timing Chain Guides (That path changes with Timing Chain Guide wear).
a. Chain Tension different with engine runing as compared to the Camshaft Timing Process.
If the Timing Chains are tighter during engine running with hydraulic lifters pressurized the Exhaust camshafts may be advanced a degree and the Intake camshafts may be retarded by a degree. For Exhaust camshafts at 110 deg BTDC may actually advance to 111 deg BTDC. The Intake Camshafts at 114 deg ATDC may actually retard to 113 deg ATDC.
b. Fixed Timing Chain Guide wear.
As the Fixed Timing Chain Guides wear the chain returning to the Idler Sprocket between the Camshaft Sprockets and Idler Sprocket decreases in effective length Advancing the Intake Camshafts and retarding the Exhaust camshafts. The Exhaust Camshaft may retard from 110 deg BTDC to 109 deg BTDC. The Intake Camshafts may Advance from 114 deg ATDC to 115 deg ATDC.
1. Background Timing Chain Sprockets and Lubrication within front cover.
A #20 Torx can be used to remove the small Torx screw holding the bearing cover in place on the Timing Chain Idler Sprocket. Place two of the Timing Chain Idler Sprocket bolts (10 mm Head x 8 mm x 100 mm) into the Idler Sprocket holes with the Heads of those two bolts in a vice. Remove the #20 Torx screw. Use Red Loctite when replacing the #20 Torx screw.
There is an oil path around one of the three 10 mm Head (8 mm) x 100 mm bolts that attaches the inner race of the Timing Chain Idler Sprocket to the engine case (The distance between two 8 mm x 100 mm bolts is smaller so the Timing Chain Idler Sprocket inner race can only be attached to the engine case one way).
This oil path is vented from the bolt hole into the needle bearing area of the inner race. The Timing Chain Idler Sprocket inner race can be attached to the engine case in only one orientation assuring that the oil pressure from the engine case is directed to the Timing Chain Idler Sprocket Bolt hole that is vented to the needle bearings..
The two sets of Timing Chain Idler Sprocket needle bearings can be seen in the photos.
The Timing Chain Idler Sprocket oil pathway entrance to needle bearings from bolt hole to the inner race (left) and exit from sprocket (right) can be seen in the small ports of the inner race and outer sprockets.
2. LT5 Timing Chain Calculations.
Timing chain breakage although very rare has been blamed on repeated engine pulses or fatigue (dead injector or bad valves for example). The timing chain calculations in this post debunk all such theories on timing chain failure.
LT5 Cranskshaft sprocket has 20 teeth.
LT5 Idler sprocket on primary side has 42 teeth
LT5 Idler sprocket on secondary side has 21 teeth
Each LT5 camshaft sprocket has 20 teeth
LT5 Primary chain has 54 pins
LT5 Secondary chain on LH has 102 pins
L T5 Secondary chain on RH has 94 pins
So...we know the camshaft sprockets rotate half as fast as the crankshaft sprocket.
Lets calculate......Crankshaft sprocket rotates 360 deg or 20 teeth. Idler sprocket primary rotates 20/42 of 360 deg or 20 teeth. Idler sprocket on secondary side rotates 20/42 of 360 deg or 10 teeth. Camshaft sprocket rotates 180 deg or 10 teeth. Exactly 180 deg like it is suppose to.
Now lets see how much of total length the RH and LH secondary chains rotate. Crankshaft sprocket rotated 20 teeth or 360 degrees. Primary chain has 54 pins so it rotated 20/54ths of its length. Camshaft sprocket rotated 180 deg or 10 teeth so for RH chain with 94 pins that is 10/94ths of its length and for LH chain with 102 pins that is 10/102nds of its length.
Lets put this another way.......each time the crankshaft sprocket rotates 360 degees, the RH chain moves 10/94ths of its length and the LH chain moves 10/102nds of its length. Or if the RH chain were to rotate its full length, the crankshaft sprocket would rotate 9.4 times and if the LH chain were to rotate its full length, the crankshaft sprocket would rotate 10.2 times.
Now...let us look at the analysis in above posts wherein a miss fire could cause chain failure.
The bad cylinder miss fires once every two revolutions of the crankshaft. That little tug on the chain would occur on the RH chain 4.7 times as it rotated its full length. That little tug would occur on the LH chain 5.1 times as it rotated its full length. And the little tug from a bad injector would occur at different locations on each chain every revolution of the crankshaft since these (4.7 and 5.1) are not whole numbers.
Start with Ben's RH Tensioner photo on how to reset chain tensioner (The RH and LH Tensioner are different).
Originally Posted by bdw18_123
I remembered seeing a really good write up over at the "other" forum quite awhile ago (which we again can't link to, I thought that was fixed? ) on how to reset a timing chain tensioner with some good instructional pictures. It was done by someone with a forum name of ZR1 at that "other" forum. I decided to go looking for it since I need to reset my tensioners. Resetting timing chain tensioner TIPS
1. Resetting the Chain Tensioner. a.A is the Transport Clip which is smaller than B (the operational clip). b. Leave A in the groove on the left end of the plunger and move B to the smaller width reset groove just left of the wider operational groove. c. Place the spring inside the plunger and insert the plunger with spring into the Tensioner Housing. d. Place the Tensioner with plunger inserted in a vice being carefull not to mark the plunger tip (left end of plunger) with the jaws of the vice. The plunger tip should be exposed so a knife edge can be inserted in the end of the tensioner housing to move Transport Clip A when the plunger is fully compressed within the tensioner housing. e. With the plunger compressed into the tensioner housing (with Transport Clip A in the groove on the left end of the plunger), insert the knife blade and move any part of the Transport Clip A further into the tensioner housing out of the groove on the left end of the plunger. f. Hold the Transport Clip A (any part of the Transport Clip) out of the groove on the left end of the plunger when you gradually open the vice. g. If you start to see the Transport Clip A, it did not catch the inside of the Tensioner Housing for transport. Recompress the plunger inside the Tensioner Housing and move any part of the Tansport Clip A one more time out of the initial groove. Gradually open the vice and you will see the plunger is now caught inside the Tensioner Housing. The Chain Tensioner is now SET for Transport.
2. Activating the Chain Tensioner. a. Rotate the crankshaft clockwise looking at the front of the engine. This will loosen the timing chain on the tensioner side of the timing chain sprockets. This will allow the tensioner to extend maximum length when the tensioner is unset in step 3 below. b. Insert the chain tensioners (Plunger set for transport) into the locator housings that will be bolted to the heads (chain tensioner lubricated with engine oil and installed into locator housing). c. Make sure the "O" rings are in place on the locator housing and that the "O" rings stay in the grooves of the locator housing (a bit of permatex sealant on the "O" ring will hold it in place). Tighten the two bolts of the RH and LH locator housnigs to the RH and LH heads. d. Make sure both left and right chain tensioner slots are alligned vertically so they allign with the left and right chain guides. e. Make sure that the oil ports of the tensioner locator housing is facing up with tensioner locator housing installed in the heads. The LH and RH locator housings are different in regard to oil port and bolt alignment (RH bolts are vertical, and LH bolts are horizontal). f. Remove allen head plug on the tensioner locator housing. g. Insert a small punch positioned through the hole (removed allen head plug) on the top of the tensioner locator housing. Tilt the punch to the side making sure you are not punching the check valve on top of the barrel of the tensioner plunger. Give the punch a sharp tap with a small hammer. This unsets the chain tensioner plunger from the transport position in the tensioner housing moving the Transport Clip A back into its original groove on the tip of the plunger. h. Install the allen head plugs in the RH and LH tensioner locator housings with blue loctite.
Unset LH chain tensioner..........................Unset/set RH chain tensioner (Photo by Craig)
Drivers Side Cams........................................ ........Passenger Side Cams
1. Insert spark plugs with a bit of anti-sieze on the threads before installing the Cam Covers to assure that nothing drops into the cylinders. 2.Leave Jeffvette Billet Aluminum Camshaft Retainers in place as the cam cover journals will take the camshaft loads once the cam covers are in place. The Camshaft Billet Aluminum Retainers do prevent the camshaft longitudinal movement however.
a. Use Loctite 518 (Permabond A136 recommended from Jerrys Gaskets) very thin coat on surface of cam covers. Do not coat 518 Loctite all the way to the edge of the journals (stay away 1/4 inch). leave 1/8 inch more or less space between Loctite 518 and outer/inner edges of any surface coated. Also, do not coat the cam covers all the way to the outer and inner edges (leave 1/8 inch more or less space between Loctite 518 and outer/inner edges of any surface coated). (Coat the grooves for the two camshaft rubber plugs on each end of each Cam Cover and same on each end of each head.
b. Lubricate all cam lobes and lifters with engine oil but do not get any oil on the Cam Cover interface surfaces. c. Place spark plug "O" rings in place and on the Cam Cover place a thin coat of 518 Loctite around each spark plug hole. d. On all surfaces keep thin coat of 518 Loctite 1/8 inch from edges of each/every surface. e. Set Cam Covers in place on Heads. f. Insert 24 SS Allen Head 8 mm (Replace original Torx-40....See....Post 67 - Removing Cam Covers (Engine In Car) for Inspections of Camshafts) 3 SS Allen Head 6 mm Cam Cover bolts with Aluminum Stat-O-Seal Washers (Do not use Loctite or Anti-sieze on Cam Cover bolts). I also used eight 1/4 inch Aluminum Stat-O-Seals for the IH coolant housings. The Aluminum Stat-O-Seals make a great lock washer as well as prevent oil leaks around the SS bolts.
Pegasus Auto Racing (Check Jerrys Gaskets for latest Stat-O Seal type Washers)
3. Tightgen all cam cover SS bolts in several steps a. Tighten All Cam Cover bolts using a #6 Allen Head wrench including the 3 #4 Allen Head bolts on the front edge of each Cam Cover. b. Check that the crankshaft is still free to rotate during and after tightening Cam Cover bolts. c. Clean any excess 518 loctite from cam covers.
4. Cam Inspection after several hours Run In a. Drivers side Cam Cover was removed after several hours of engine time after installation of regrind camshafts. The Cams and Cam Journals were found to be in perfect condition with no unusual wear marks. b. The Billet Camshaft Retainers were found to be in perfect condition with all bolts tight. c. The Lubrication condition was found to be perfect with all Cams and Lifters fully lubricated.
The PCV system with the dual PCV valves (each with its own vacuum characteristic) in conjunction with an Oil Catch Can evacuates the crankcase. See Elite Oil Catch Can Installation Details.
Oily gasses traveling upwards from the Crankcase Ventilation Cover bring oil into the IH which two small holes (each IH) let that oil drain back into the Head (The 90' being a bit different than the 91' in that regard with respect to oil drain hole sizes). From the IH the gasses are sucked through the PCV valves from each side of the IHs through two hard lines.
It is assumed that oil in the camshaft area drains back down into the crankcase through relatively small drain holes in the Heads. The area under the Cam Covers is then at the same pressure (depending on the capacity of the oil drain holes in the heads to pass gasses the opposite direction into the Camshaft area) as the Crankcase (compression gasses passing past rings).
The vacuum in the PCV return line and the Cam Cover Vents are a bit different as the Cam Cover vent line is attached to the Air Horn and the PCV return line is attached to the Plenum behind the Throttle Body. That means at idle you get a lot of vacuum pulling on the dual PCV valves and almost zero pulling on Cam Cover vents. At Wide Open Throttle (WOT) you get about equal vacuum on both maybe.
So.....you are pulling most oil through the Cam Cover Filters l at WOT and if you have a clogged air filter you are pulling even more vacuum at WOT from the Cam Cover vents but that is prolly just not a factor. Now if the Cam Cover Filter is clogged up, you might have a positive crankcase pressure since there is not much vacuum on the PCV system. The crankcase pressure would be greatest at WOT with the most gasses escaping into the crankcase around the rings.
In the case of a positive crankcase pressure you might see oil around the Cam Covers. Just guessing here to determine what can be done if the Cam Cover Filtersl get clogged upCam Cover Filters
It seems that the Crankcase pressure would be totally dependent on the condition of the rings. PCV valves, and Cam Cover Filters. The amount of gas passing through the PCV system and Cam Cover Vents is equal to the amount of gas passing past the rings at all times.
I switched from Scotch Brite to Marc Haibeck's new Cam Cover Vent filter material Cam Cover Filters
Plenum Pull 1. Just make sure you drain enough coolant if you do not have Throttle Body Coolant Blocked.
2. Electrical Connections associated with Plenum Pull (1990 ZR-1)
The 4 connectors on the Distributorless Ignition System (DIS) under the plenum are not interchangeable. The 2 Connectors towards the front of the DIS carry the coil primary controls signal. The small one at the back of the DIS is switched B+. The big one carries ECM signals. a. Disconnect two larger electrical plugs under front of DIS to underside of DIS from front of plenum. b. Disconnect the smaller electrical plug and ECM signal plug (1/4 inch socket with short extension) under rear of DIS from rear of plenum.
3. Tools a. Used a 1/4 inch socket wrench with short extension and 1/4 inch socket to install the bolt in the DIS module electrical connection from rear of plenum with plenum up 3 inches (DIS attached under the Plenum). b. Used a 3/8 inch socket wrench with 6 mm allen heads for plenum SS bolts.
Two Allen Head wrenches (6mm and 3mm),
Two flat head Screw drivers and ...................................1/4 inch socket wrench with 1/4 inch socket
TB bracket wrenches (7mm and 9mm)..........................and short extension for DIS Connector
4. The 10 Minute Plenum Removal (1991 LT5 after Eliminated TB Coolant, Installation of Oil Catch Can and Installation of SS Allen Head Bolts).
B. Plenum Removal Steps (assuming you have TB Coolant Blocked). If not.....remove some coolant before you start.
1. Disconnect Battery (Check Battery Condition and Jumper GOOD Battery as FIRST CHECK).
2. Remove Samco (or stock) Air Duct (large flat screw driver).
3. Remove Oil Catch Can Hose (If Oil Catch Can Installed) to Plenum and PCV Dual Connector on back of Plenum (small flat screw driver).
4. Remove Throttle Body Cables (two including TB Shield and two top (I have 3mm SS Allen Head) screws on Plenum) and TB Connector (7mm and 9mm wrenches).
5. Remove Fuel Regulator Vacuum Hose "L" rear of Plenum.
6. Disconnect MAP Vacuum hose from MAP (Manifold Absolute Pressure) and from rear of Plenum.......
(in case it gets intangled with other wires/hoses I just disconnect MAP bracket from Plenum).
7. Disconnect Passenger Side Plenum Vacuum (and Drivers side Plenum Vacuum if secondaries not removed).
8. Disconnect Brake Boost Vacuum line Drivers Side Rear of Plenum.
9. Remove three 6mm Allen Head SS Fuel Line Bolts and two fuel lines (6mm Allen Ball Head Socket) or Torx-40 stock bolts.
10. Open gas cap to prevent fuel lines from leaking when removed from fuel rail.
11. Remove 12 Allen Head SS Plenum Bolts (6mm Allen Ball Head Socket with Extension) or Torx-40 stock bolts.
12. Lift Plenum from Gasket (front only) and remove two Cam Cover PCV Vent Rubber Connectors to Air Horn.
13. Disconnect two DIS (Distributorless Ignition System) Connectors front of DIS.
14a. Disconnect large Purge Vacuum line under front of Plenum (91').
14b. Disconnect small vacuum line under front of Plenum and larger vacuum line from drivers side of Plenum going to Charcoal Canister under left head light (90').
15. Disconnect two small electrical connectors rear under Plenum (MAP and DIS).
16. Unscrew 1/4 bolt in Main DIS Connector rear of Plenum.
17. Remove Plenum.
1. After removing Plenum use high pressure Air Pressure to clean all debris around Injectors before removing the Injectors.
2. Fuel Rail Removal. a. There are 4 bolts that hold the fuel rail in place...remove them. b. Disconnect the fuel lines at rear of fuel rail (there are "O" rings). c. Disconnect the electrical to each injector (spring loaded clip). d. Wiggle the fuel rails with upward pressure popping the injectors out of the Injector Housing. e. The Purge vac line is on top as well as Cruize control vac line on passenger side and Aux secondary vacuum on drivers side. f. Remove the clips holding each injector on fuel rail and pull injectors out of fuel rail.
3. Installation of New Injectors.
Remove the protective blue plastic cape protecting the secondary
injector "O" ring before installing into the Injector Housing.
4. "O" Rings in IH and on Injectors......Primary LEFT ("O" Ring in IH) and Secondary RIGHT ("O" Ring on Injector)
Used just a tad of white grease on the "O" rings (Primary and Secondary Injectors) for easy installation of injectors.
5. Bracket install Trick (Purge connector through rear drivers side runners of Plenum). a. Modified bracket on passenger side of Plenum for Purge connector which was attached to TB coolant return (since removed). b. Kept the bracket and reinstalled bracket on passenger side of Plenum (second bolt from fire wall) for Purge connector. c. The TB return line to coolant tank in front of passenger side windshield has been capped off with brass plug.
6. Tools. a. Used a 1/4 inch socket wrench with short extension and 1/4 inch socket to install the bolt in the DIS module electrical connection from rear of plenum with plenum up 3 inches (DIS attached under the Plenum). b. Used a 3/8 inch socket wrench with 6 mm allen heads for plenum SS bolts.
7. Electrical Connections associated with Plenum Pull (1990-1991).
The 4 connectors on the Distributorless Ignition System (DIS) under the plenum are not interchangeable. The 2 Connectors towards the front of the DIS carry the coil primary controls signal. The small one at the back of the DIS is switched B+. The big one carries ECM signals.
a. Attach two larger electrical plugs under front of DIS to underside of DIS from front of plenum. b. Attach the smaller electrical plug and ECM signal plug (1/4 inch socket with short extension) under rear of DIS from rear of plenum.
8. Engraving Tricks.
Thanks to Carter for the great engraving on coolant manifolds and TB plate
Vacuum Systems 90' and 91' (Secondary and Cruize/HVAC)
Vacuum Systems 90' and 91' (Secondary and Cruize/HVAC)
1. Secondary Vacuum System
The first photo shows details of the vacuum plumbing around the Secondary Vacuum Solenoid and Secondary Vacuum Reservoir Including the Check Valve. The second photo is the complete Secondary Vacuum System.
The Check Valve allows plenum vacuum to be seen by Secondary Vacuum Reservoir but does not allow plenum to see Vacuum pump vacuum.
2. Cruize Control and HVAC The vacuum line on the passenger side of the plenum is for the cruise control and HVAC. That vacuum is a separate system.
The cruize control and HVAC Vacuum are NOT eliminated having nothing to do with the secondary vacuum system removal. See item #3LT5 Eliminated Systems
The cruize control plenum vacuum line (mid plenum connection passenger side) and L connector is shown on left and Cruize control is shown on right. A vacuum line is connected to one of the connections shown left photo (L connector) running forward under plenum (out front of plenum) to drivers side wheel well. There it connects to a connector going forward to vacuum reservoir under drivers side head light (bottom photo) and backward to Cruize Control shown in right photo just above battery on drivers side. The other vacuum hose connected to the Cruize Control is for the brake pedal cruise cancel function.
The second connection shown in left photo (L connector) connects to the HVAC vacuum line included in passenger side fuel injector wire harness.
4. Checking Vacuum System. Before you tighten down the Plenum (with Plenum tipped up in front) and ALL vacuum lines, and DIS module connections in place....check your vacuum systems.
With all vacuum lines connected, turn key on and listen for vacuum pump to shut off. If it does not shut off, start at the closest vacuum line to the vacuum pump disconnecting the line and holding your finger over the end. If the pump shuts off the leak is on other side of that. Go to next fitting and do the same until you are past the leak wherein the vacuum pump will NOT shut off. You have now located the leak.
If the Plenum has NOT been removed Check between Vacuum Pump and Plenum first....then check Drivers side Plenum Vacuum Connection to see if the Check Valve under Plenum is leaking. Disconnect that vacuum fitting and hold finger over end of vacuum line to see if pump stops cycling...if pump stops cycling the Check Valve is leaking.
Also check your HVAC and Cruize Control Vacuum System (check ALL connections). Also check your EVAP Purge system connections (charcoal canister which is under drivers side headlight on your 90'). That single small vacuum port under front of plenum facing rearward (90' only) is for the Evap Purge System. The second larger vacuum port on drivers side lower front of plenum is the main vacuum line for the Charcoal Canister. The second Vacuum port right next to that Charcoal Canister port is your PCV Vacuum port.
With the key on, ground the pink wire in the green connector (third from drivers side) on ECM. Use a small finishing nail stuck in alongside the wire connector with an alligator clip pigtail attached to the end for grounding. This will activate the Secondaries which you can watch with the plenum tipped up in front before you bolt it down. This after you are sure you have NO vacuum leaks in the Secondary System.
Eliminating IH Housing Throttle Body (TB) Coolant system
Eliminating IH Housing Throttle Body (TB) Coolant system.
Install 1/8 inch NPT allen head pipe plugs (21/64 or 11/32 drill) two each side of Plenum (Two each TB Coolant and Injector Housing (IH) Coolant) as shown (The associated two IH coolant ports in the IH can also be plugged on each side).
Remove hose and tubing left and right side of plenum, plug hose return to coolant tank passenger side. See item #9 TB Coolant Return Modified. Initial Coolant Fill may be somewhat affected by the TB Coolant Elimination (see item #4 Initial Coolant Fill).
Note: The TB coolant path back to the passenger side overflow tank does provide a path for air and potential air lock to return to that passenger side tank during initial coolant fill. However, the Plenum to TB coolant hose sits only an inch or so above the IH coolant manifolds on the passenger side so the benefit of using that path to bleed air vice the top of the coolant manifolds to the radiator is very small. Marc has decided to bypass the TB coolant (vice eliminate all TB coolant hoses) leaving that coolant path back to the passenger side overflow tank in place to assure issues would not arrise on rebuilds for those unaware of coolant initial filling and water pump potential air locks.I also park on KwikLift sloped upward which assures IH coolant manifolds are voided of air at all times (especially if engine is reved a bit).
The 5th plug (Plenum Vacuum) is for Plenum Vacuum drivers side only which was connected to the vacuum reservoir. The tubing can be removed and a 1/8 inch NPT allen head pipe plug inserted exactly like the plenum coolant plugs.
a.When you run the tap....keep checking the pipe plug for depth so you end up tight and flush. b.When you run the Drill.......remember you are in ALUMINUM so go very easy and slow!!! (you can do it without a drill press). c. Use a bit of Permatex gasket sealer or Teflon tape on the pipe plugs.
Install Dorman freeze plugs 555-108 with Loctite 262 to plug the secondary shaft ports for a complete elimination of Secondary throttle shafts and associated vacuum canisters. Summit Racing Freeze Plugs 555-108
Stainless Steel Air Box and Air Filter (L98 and LT5)
Stainless Steel Air Box and Air Filter (L98 and LT5)
The Stainless Steel Air Box has been offered for those that want to add Bling and Higher Intake Air Flow for the LT5 or L98
1. SS Air Box Installation and Air Filter Selection
George Braml fabricates the SS Air Box.
Just an installation tip....If you use that Orange FRAM Air Filter you will find it about 1/4 inch too high. The bottom end of the SS Air Box Square Filter Retainer lip will not engage the Built In (L) of the Air Box at the bottom end as shown in the first photo (the Orange Fram Air Filter has a gap at the bottom end). You will also notice the two Retaining screws for the Square SS Air Box Filter Retainer have tilted towards the engine indicating the top Square Retainer has moved upward out of the SS Air Box (L) at the bottom end.
If you look closely at the SS Air Box Square Filter Retainer you will see a cut out about 1/4 inch deep and the width of the Square Filter Retainer on the bottom end. The height of the Air Filter cannot be higher than that cut out (The Orange Fram Filter is about 1/4 inch higher than that cut out).
The K&N 33-2035 High Flow Air Filter is the correct Air Filter matching the SS Air Box Cut Out.
George Braml did a perfect fabrication job on the L98 SS Air Box as he did on the LT5 SS Air Box (Both SS Air Boxes are IDENTICAL)
2. Facts and Photos
The L98 and LT5 SS Air Box and Air Filters are Identical.
A. The Air Filter opening is 9.5 in x 16.25 in or 154 square inches (both OEM and SS).
B. The Air path inside the Air Filter housing to the oval outlet is 1 in x 17.25 in or 17.25 square inches (both OEM and SS).
C. The OEM metal cover Louvers are 3/8 in x 4 in or 1.5 square inches and there are 24 Louvers or 36 square inches for Air Flow into the Air Filter area (OEM only).
D. Space between top of OEM metal Louvered cover and closed hood exceeds 1 inch all around (more space with SS Air box since metal louvered cover is not used.
C. Using SS Air Box with FRAM decreases the space between top of Air Filter and closed hood by 1/4 inch or 12.5 square inches around the perimeter of the Air Filter.
D. Using the SS Air Box with K&N High Flow Air Filter eliminates the need for the OEM metal Air Box cover (36 inches of air flow area) making available the total air flow area of 154 square inches to the K&N 33-2035 High Flow Air Filter.
E. The K&N 33-2035 High Flow Air Filter is Washable and Reusable.
SS Air Box installed with FRAM Air Filter with bottom of Filter Square Retainer not engaged
SS Air Box and OEM Air Box bottom compared showing where they ride on ridge
of radiator shroud (SS Air Box) and between ridges of radiator shroud (OEM Air Box)
SS Air Box and OEM Air Box bottom compared showing where they ride on ridge
of radiator shroud (SS Air Box) and between ridges of radiator shroud (OEM Air Box) close up
SS Air Box installed showing 1/4 inch Cut Out on lower side of Square Air Filter Retainer
with K&N High Flow Air Filter fitting under small cross member
OEM Air Box with metal Louver cover
FRAM Air Filter exceedes the SS Air Box Square Retainer 1/4 inch cut out height
(filter shown above SS metal)
K&N 33-2035 correctly sits even with the 1/4 inch cut out
For the installation of the K&N 33-2035 air filter in the "stock" Air Filter Housing......SEE
3. Technical Discussion
The air is drawn from top side of Air Filter in the OEM set up through the louvers in the metal cover. There is a gap of at least an inch between that Air Filter metal cover and closed hood (OEM or SS Air Box).
With the SS Air Filter housing, there is NO metal cover and air is drawn from air gap between the filter and closed hood not restricted by the 36 square inch Louver area of the OEM Metal cover. With a K&N High Flow Air Filter that gap is 1/4 inch larger (than when using a FRAM Air Filter).
The OEM filter housing metal cover will accomodate both FRAM and K&N 33-2035 Air Filters. The difference between the SS Air Box and OEM Air Box is that the SS Air box rides a bit higher requiring the 1/4 inch Cut Out for the small front crossover (see photos of the bottom of both the OEM and SS Air Box.
Because of the Cut Out the SS Air Filter housing with correct K&N 33-2035 High Flow Air Filter will sit at the same height as an OEM Air Box. However if you use a higher FRAM Air Filter that exceedes the Cut Out height in the SS Square Retainer, the overall height of the top of the filter has changed and will interfere with the front small corss over.This will in turn cause interference bwtween the FRAM Air Filter and small cross over preventing the Top Square Retainer of the SS Air Box from engaging at the bottom end.
The L98 and LT5 are IDENTICAL in regard to these issues as the OEM Air Filter housings are IDENTICAL and the radiator shrouds appear to be IDENTICAL in regard to top side of that shroud.
4. Water Deflector
The Water Deflector which sits under the end of the OEM Air Box (or SS Air Box) to prevent water from being sucked into the Air Intake from the front grille. What it also does is prevent cooler air from entering the Air Intake from the grille. I deleted the Water Deflector from both the L98 and LT5 SS Air Box installations.
5. Powder Coating or Painting SS Air Box I did not Powder Coat or Paint the SS Air Box as it looks very very nice as a SS Machined look and the welding is absolutly perfect......so why cover up with Powder Coating or Paint
1. Pilot Bearing
Two issues important in the clutch area are the replacement of the throwout bearing and Pilot Bushnig/Bearing. There has been much confusion over which Pilot Bushing/Bearing is to be used. GM has changed their part numbers several times and are currently referring to the bearing (part #14061685) to be used.
It has been suggrested to NOT use this bearing as it is a needle type bearing designed for 6.2L diesel trucks which have a limit of only 4,000-4,500 rpms. The theory is that those little needles will turn at over 7,000 rpms. It has therefore been suggested the ideal bushing replacement is a bronze type with three grooves (or flutes) spiraled inside and is available under the GM part number 10125896.
This really only applies to drag racing where you drop the clutch at high rpms. At all other times the RELATIVE rpm difference between the transmission spline and the flywheel are low and much less than 4,000 rpm. The needle bearing pilot would be the best choice for most applications excluding drag racing.
Matter of fact except when starting out in first gear engaging the clutch a bit above idle rpm, one trys to match transmission spline rpm with engine/flywheel rpm when selecting higher or lower gears. This method of shifting gears is also much better for the syncros (Depress the clutch, take it out of gear, syncronize rpms between the flywheel and transmission spline in the gear to be selected, and then shift to higher or lower gear, release clutch).
I use the Needle Type Pilot Bearing
2. Pilot Bearing Depth
Originally Posted by Marc Haibeck
You should drive the pilot bearing in until it seats at the bottom of the bore. That will be about 14 mm deep.
Note that a bronze bushing often comes loose and spins in the crankshaft. Installation of the bushing with bushing retaining compound will not solve the problem. I recommend to use only the roller pilot bearing. It will never come loose. GM PN 14061685.
All measurements from the surface of the rear of the crankshaft (bottom arrow).
The depth to the plug is 34.90 mm (top arrow).
The depth to the raised bottom of the pilot hole is 31.75 mm (Second arrow from top).
The depth to the raised portion of the pilot hole (the pilot bearing housing in the crankshaft) is 9.5 mm (third arrow from top).
The height of the Roller Bearing (width of outer race) is 17.45 mm.
So......I am assuming the new roller bearing pilot should be sunk in past the raised portion of the housing (third arrow from top) about 4.5 mm or .175 inches.
In other words just a bit past the raised portion of the pilot bearing hole. This would put the other end of the pilot bearing almost exactly to the raised portion near the bottom of the pilot hole at 31.75 mm (second arrow from top).
Using a Blind Hole Slide Hammer to easily pull the old Pilot Bushing.
The height of the Roller Bearing is 11/16 in (17.45 mm) ....... The face of the Bronze Pilot Bushing I removed ........................................ ........................................ ...............was even with the reduced diameter of the bore.
3. Dimensions of Black Label Transmission which except for Throwout Bearing Inside Diameter are identical to Blue Label Transmission.
1 inch or 25.4 mm........................................ ................................1.373 inch or 34.87 mm
4. Clutch Fork
The Clutch Fork pivots on a pivot post attached to the Bell Housing. The outer part of the Clutch Fork lever is pushed in by the rod of the Clutch Slave Cylinder.
Inside the Bell Housing Left and Outside the Bell Housing Right.You can see in the Left Photo that the Clutch Fork can be slipped to the Right off the pivot when positioning the Bell housing on the engine so the Clutch Fork Fingers can be positioned on the Throwout Bearing during installation of the Bell Housing.
5. Throwout Bearing
The throwout bearing is locked inside the pressure plate fingers with a circular wire clip. The Throwout Bearing is inserted inside the pressure plate before the pressure plate and clutch disk are attached to the fly wheel.
When the outer part of the Clutch Fork lever is pushed in by the rod of the Clutch Slave Cylinder, the other end of the Clutch Fork is pulled away from the center of the Pressure Plate. The Fingers of the Clutch Fork engage the corners of the throwout bearing square collar and pulls the throwout bearing out and away from the clutch surface (Center Force Clutch/Pressure Plate shown). This assembly shows a Blue Label Throwout bearing as a 95' ZF S6 40 Transmisison was used with a 91' engine.
The throwout bearing pulls the Pressure Plate Fingers which each finger has a pivot point at the outer edge of the pressure plate with an attachment to the pressure plate at approximately the half way point to the outer edge. This pulls the pressure plate surface away from the clutch disk releasing the clutch.
The outer part of the throwout bearing is always rotating with the clutch (engaged or not). The inner part of the throwout bearing does not rotate but is lubricated to slide in and out on the outer collar of the transmission input shaft.
That outer collar of the ZF S6 40 Transmissions is of a different diameter for 90-93 Black Label and 94-95 Blue Label ZF S6 40 Transmissions Throwout Bearings and Clutch Forks
The only hydraulics involved is the hydraulic fluid (DOT 3 or DOT 4) between the Clutch Master Cylinder and Clutch Slave Cylinder. Which Clutch Fluid Reservoir is hidden below the ECM just in front of the dirvers side under the hood.
6. Installation of the Transmission
I ALWAYS use Jerry's Pilot Bearing which has a height of 11/16 inch (.687 inch).
You have about 1 inch to work with on the end of the Transmission Input Shaft and I always try to set up the seating depth of the Pilot Bearing to fully install within that last 1 inch of the Transmission Input Shaft.
What I do to insure that.....as I position the transmission using my Transmission jack......it is easy to slide the Transmission Input Shaft Collar through the throwout bearing and the Transmission Input spline through the Clutch Plate (as I recall I have someone depress the Clutch as I install the Transmission).
The Transmission usually slides easily until the tip of the Transmission Input shaft meets up with the Pilot Bearing at which point I have approximately 11/16 inch left for full contact between the Transmission and Bell Housing which dimension is what I am looking for correct engagement of the Transmission Input Shaft with the Pilot Bearing. I then "wiggle" up and down...side to side as I push on Transmission and it always pops in that last (approximately 11/16 inch).
If you do not have approximately 11/16 inch ....Pilot Bearing installation depth may need adjustment.
I do use some good wheel bearing grease on the Pilot Bearing and on the Throwout Bearing, Transmission Shaft Collar before installation of the Transmission.
NEW 95' ZF S6-40 Transmission (Blue Label)..Harbor Freight 800 lb Capacity Transmisison Jack
1. Transmission Jack
The Transmission Jack works perfectly with the ZR1 on KwikLift18 inches off the ground (Perfect height). The 800 lb Capacity Transmission Jack has roll and tilt adjustments for a perfect match when locating the transmission on the Bell Housing (Clutch depressed last 2 inches of installation). The transmission (on Transmission Jack) can be rolled under KwiKLift from the front as the shifter will clear the cross members and bell housing/oil pan (slipped along side of oil pan).
2. KwikLift a. KwikLift (wheels 18 inches off ground). b. KwikLift Creeper (Perfect with KwikLift). c. Park Z on KwikLift for ease of inspection under engine. d. Key in ignition, release park brake, in neutral.....roll out of garage without starting engine.
For those of you who feel like a KLUTZ (Like I did) when trying to get the Z up on an inclined ramp such as KwikLift for repairs when the Z is in non operable condition.....here is a solution.
As you prolly know, the Z can be towed easily using a chain or synthetic tow rope from either the back end (attached underneath to near center of leaf spring) or front end (attached underneath to center of frame cross member). The Z cannot, however, be pushed by another vehicle (The Z can be hand pushed easily but not up inclines) from either end because of the fiberglass on both ends.
I welded a padeye at the center of two 1-1/2 x 1-1/2 x 45 inch long steel box sections welded side by side (1-1/2 x 3 x 45 inch steel beam). I welded two hangers (one on each end of the steel beam). I can just hang the 1-1/2 x 3 x 45 inch steel beam on the end of Kwiklift to pull from the center padeye between each ramp with a wire rope come-a-long attached to the rear or front of any vehicle.
I use a long chain the first two pulls with KwikLift yellow chocks set during resetting of the chain length (the wire rope come-a-long cannot reach from one end of the KwikLift to the other end without starting out with a chain connection).
I call this steel beam KLUTZ (KwikLift Utility Towbar for Zs)
I actually tested the beam (pulled Z up ramp) with just one 1-1/2 x 1-1/2 x 45 inch box section then doubled up in final design.
3. Hydraulic Aluminum Floor Jack (3 ton) a. Pittsburgh Racing b. Very low initial height and weighs 55 lbs. c. High lift rate.
See Lifting the ZR-1 for a specific discussion regarding lifting the ZR-1 with a floor jack, jackstands, and ramps.
4. Differences between Black and Blue Label transmisisons Pete says the 1995 ZF S6-40 transmission has a crash thru detent for reverse which means you have to push a little harder to the right to get it in reverse. The original 1991 has the lock out which is more positive as you have to compress the lock out upward to shift into reverse. The 1991 ZF S6-40 shifer is easier to push to the right than the 1995.
Bill Bourdeau says The ’95 and ’96 ZF transmission (ZF P/N 1052 000 089) has a “crash-thru” shifter with reverse requiring additional sideways force when entering the neutral gate portion of reverse to let the operator know he/she is about to engage reverse gear. The revised internal shift shaft mountain detent pad with raised reverse detent pad causes a brief higher tactile feedback (additional counter-pressure) as the spring loaded detent roller ball must climb up to a slightly higher level just before engaging reverse thus the name crash-thru reverse. Bill's "C" Beam plates are installed (transmission end torqued to 37 ft-lbs and differential end torqued to 59 ft-lbs).
5. Throwout Bearings
I have a 91' ZF S6-40 Transmission (Black Label) Parts List No 1052-000-035 with a collar diameter of 1.373 inches and a 94'-95' ZF S6-40 Transmission (Blue Label) Parts List No 1052-000-087 with a collar diameter of 1.305 inches.
a. Here is a source for the 90'-93' ZR1/LT5 Throwout BearingPower Torque Systems Throwout Bearing Part #: 23243 b. Here is a source for the 94'-95' ZR1/LT5 Throwout BearingPower Torque Systems Throwout Bearing Part #: 23244 c. This is exactly what the Throwout Bearing looks like as cited above in both cases as the differences in internal diameter is not noticeable from a picture only.
d. The square end of the Throwout Bearing is prevented from rotating on the transmission collar by the Clutch Fork. The Throwout Bearing slides in and out on the transmission collar when you depress the clutch pedal (Lubricate the transmission collar when installing the transmission so the Throwout Bearing slides freely during operation of the clutch pedal). e. The other end of the Throwout Bearing which rides against the pressure plate fingers is locked to the pressure plate fingers by a wire clip and always rotates with the flywheel with the clutch engaged or not (the three tabs on the Throwout Bearing are locked between three sets of fingers of the pressure plate). f. If the Throwout Bearing locks up with the square end forced to rotate, the square end will spread the Clutch Forks completing the failure of the Throwout Bearing as well as the Clutch Fork. g. As I recall, typically a Throwout Bearing does not rotate at all when the clutch is not depressed unlike the Throwout Bearing of the LT5.
6. Clutch Replacement TIPS (REMOVAL)
1. Drop the exhaust manifolds and release the exhaust system from the two transmission hangers and differential hangers (Or drop exhaust pipes after CATS only). Drag exhaust out of the way.
2. Place jack under oil pan with 2x4 between oil pan and jack plate. Jack up a tad and go to item 3.
3. Remove "C" Frame Bolts and remove "C" Frame. Have in hand ZF Doc "C" Frame Plates for the re-installation of "C" Frame Later.
4. After "C" frame is removed, Lower engine (jack under oil pan) a few inches.
5. Remove universal joint on drive shaft to rear by differential. Mark drive shaft so you get it installed for possible correct balance later. Pull drive shaft from transmission. Beware of transmission fluid leaking all over once drive shaft is removed from transmission.
6. I would drain transmission fluid before I start this job and replace with new Castrol TWS 10W-60 later after reinstallation of transmission. Get yourself a 17 mm Allen Wrench also for transmission plugs. Castrol TWS 10W-60 I just buy Castrol TWS 10W-60 as well as Amsoil 10W-40 (Engine) online. Transmission ZF S6-40 takes 4.4 pints or 2.1 Liters of Castrol TWS 10W-60.
7. On top side remove shifter ****, and shifter boot so you can lower transmission later with shifter attached. The lower you can get the rear of the engine the better but make sure your cam covers do not hit brake booster of fire wall as you lower rear of engine a bit.
8. Remove clutch slave cylinder and leave it hang.
9. Remove transmission bolts (jack under oil pan and with another jack under transmission (the best is transmission jack), use BIG flat head screw driver between transmission and bell housing as it takes some pressure as you jack up and down a bit to free the transmission from the pilot bearing. There are some electrical connections on transmission you remove before pulling the transmission free.
10. Remove bell housing bolts. Pull Bell housing off but watch the throw out bearing as it stays with the pressure plate. The black label and blue label transmissons take different throw out bearings.
11. Remove pressure plate bolts being carefull to loosen bolts equally all around the pressure plate a step at a time. Do not just remove one bolt at a time. Remove pressure plate (it will fall off once all bolts are removed. The clutch plate will also fall off.
12. You might want to now inspect the pressure plate surface and surface of the flywheel.
13. You also want to remove the pilot bearing (there are pilot bearing pullers if it will not come out with flat screw driver wedging it out). I would have a new pilot bearing/bushing on hand.
INSTALLATION
1. Lubricate the new pilot bearing (Lubricate Needle Type Pilot Bearing, Do NOT Lubricate Oil Lite Pilot Bearing).
2. Remember to torque the pressure plate bolts uniformly in steps.
3. Remember to insert clutch plate alignment tool with clutch depressed before trying to install transmission.
4. It also helps if someone presses the clutch as you insert transmission releasing the new clutch plate for better alignment with transmission spline.
5. When you attach bell housing there is a trick to get the throwout bearing mating with the yoke properly. The Clutch Fork can be slid to the drivers side of the Bell Housing (elongated hole with spring clip) once the transmission is removed. This will disengage the Clutch Fork from the Throwout Bearing for Bell Housing removal and installation.
6. I already mentioned marking the drive shaft and re-installing as it was removed from rear differential yoke.
7. Remember torque on front and rear C4 Beam Plate bolts (59 ft-lbs on rear two bolts and 37 ft-lbs on front two bolts).
8. Use alignment tabs provided by ZFDoc with C4 Beam Plates which align the "C" frame properly with frame just near the shifter assembly.
9. Leave 4 original washers on the rear (Differential) off the bolts. I installed 2 of the 4 original washers on the front (Transmission) bolts as they were originally.
10. The Tranmsmission C4 Beam Plate beveled corner faces toward the front of the transmission.
A transmission jack is not to expensive and Harbor Freight sells one for $129.
7. Installation of the Transmission
I ALWAYS use Jerry's Pilot Bearing which has a height of 11/16 inch (.687 inch).
You have about 1 inch to work with on the end of the Transmission Input Shaft and I always try to set up the seating depth of the Pilot Bearing to fully install within that last 1 inch of the Transmission Input Shaft.
What I do to insure that.....as I position the transmission using my Transmission jack......it is easy to slide the Transmission Input Shaft Collar through the throwout bearing and the Transmission Input spline through the Clutch Plate (as I recall I have someone depress the Clutch as I install the Transmission).
The Transmission usually slides easily until the tip of the Transmission Input shaft meets up with the Pilot Bearing at which point I have approximately 11/16 inch left for full contact between the Transmission and Bell Housing which dimension is what I am looking for correct engagement of the Transmission Input Shaft with the Pilot Bearing. I then "wiggle" up and down...side to side as I push on Transmission and it always pops in that last (approximately 11/16 inch).
If you do not have approximately 11/16 inch ....Pilot Bearing installation depth may need adjustment.
I do use some good wheel bearing grease on the Pilot Bearing and on the Throwout Bearing, Transmission Shaft Collar before installation of the Transmission.
1. Is car being driven or is car standing still? (see tccrab diagnoses below)
2. If car is standing still, at what engine rpm does vibration occur with clutch pedal released and transmission in neutral? Belt tensioner, Harmonic Balancer (HB), crank shaft, engine uneven combustion, flywheel, clutch plate, pressure plate check
3. If the car is standing still, depress clutch pedal with transmission in neutral and note what engine rpm vibration occurs? Belt tensioner, HB, crank shaft, engine uneven combustion, flywheel, transmission pilot bearing, transmission input shaft, pressure plate, clutch plate check
4. If the car is standing still with transmission in gear and clutch pedal depressed does vibration exist? Pilot bearing, clutch plate, transmission input shaft check
Assuming no vibration in steps 2-4 above.
3. If car is driven, does vibration occur in all gears at that same rpm (different speeds mph)? transmission input shaft check
4. If car is driven, does vibration occur in all gears at same speeds mph? Drive shaft U joints, drive shaft, short shaft U joints between differential and wheels, wheels, road (try a different road) check
5. If car is driven, does vibration occur with clutch pedal depressed? Let the car maintain speed mph and depress clutch pedal letting engine rpm drop to idle with transmission in gear (this will put maximum relative motion between transmission input shaft and pilot bearing in flywheel). Clutch plate, pilot bearing, transmission input shaft check
6. If car is driven, does vibration occur with clutch pedal not depressed? Let the car maintain speed mph and release clutch pedal (clutch pedal not depressed) letting engine rpm drop to idle with transmission in neutral. Clutch plate, transmission input shaft, pilot bearing check
7. Did you recently (just before vibration issues) change anything? Tires, wheels, drive shafts, clutch plate, pressure plate, flywheel, pilot bearing, "C" Beam bolts, "C" Beam, transmission, tansmission input shaft, transmission input shaft bearings, transmission output shaft bearings, injectors, plugs, belt tensioner, HB, etc. check (The reason I ask is there is always a possibility of an improper installation of new parts or new parts require balance).
What you cannot separate doing steps 1 through 7 above are the following:
A. Clutch plate from transmission input shaft.
B. Drive shaft from differential, short shafts from differential, wheels from short shafts.
C. Flywheel from pressure plate.
D. Flywheel from crankshaft, belt tensioner, HB, uneven combustion.
E. Transmission output shaft from drive shaft.
You can separate the following doing steps 1 through 7 above:
A. Pressure plate from clutch plate.
B. Flywheel from clutch plate.
C. Transmission input shaft from pressure plate.
D. Transmission input shaft from transmission output shaft.
E. Transmission input shaft from drive shaft and drive train beyond drive shaft.
F. Clutch plate from crankshaft, belt tensioner, HB, uneven combustion.
I have a 91' ZF S6-40 Transmission (Black Label) Parts List No 1052-000-035 with a collar diameter of 1.373 inches and a 94'-95' ZF S6-40 Transmission (Blue Label) Parts List No 1052-000-087 with a collar diameter of 1.305 inches.
a. Here is a source for the 90'-93' ZR1/LT5 Throwout BearingPower Torque Systems Throwout Bearing Part #: 23243 b. Here is a source for the 94'-95' ZR1/LT5 Throwout BearingPower Torque Systems Throwout Bearing Part #: 23244 c. This is exactly what the Throwout Bearing looks like as cited above in both cases as the differences in internal diameter is not noticeable from a picture only.
d. The square end of the Throwout Bearing is prevented from rotating on the transmission collar by the Clutch Fork. The Throwout Bearing slides in and out on the transmission collar when you depress the clutch pedal (Lubricate the transmission collar when installing the transmission so the Throwout Bearing slides freely during operation of the clutch pedal). e. The other end of the Throwout Bearing which rides against the pressure plate fingers is locked to the pressure plate fingers by a wire clip and always rotates with the flywheel with the clutch engaged or not (the three tabs on the Throwout Bearing are locked between three sets of fingers of the pressure plate). f. If the Throwout Bearing locks up with the square end forced to rotate, the square end will spread the Clutch Forks completing the failure of the Throwout Bearing as well as the Clutch Fork. g. As I recall, typically a Throwout Bearing does not rotate at all when the clutch is not depressed unlike the Throwout Bearing of the LT5.
2. Throwout Bearing has two Bearings. A. When you engage the clutch placing pressure (pulling with the Clutch Fork) on the Throwout bearing the inner bearing is working/spinning. B. When you release the clutch, the outer bearing is always spinning. C. The inside collar is prevented from spinning by the Clutch Fork. The Outside collar is always spinning with the Pressure Plate. D. The Clutch Disk is spinning or not depending on if it is compressed between the Pressure Plate and the Flywheel.
3. Clutch Forks.
a. The Clutch Fork can be slid to the drivers side of the Bell Housing (elongated hole with spring clip) once the transmission is removed. This will disengage the Clutch Fork from the Throwout Bearing for Bell Housing removal and installation. b. I have a 90 (L98) with ZF S6 40 trans also and I expect that the clutch fork is identical (90 ZR1 (LT5), 91 ZR1 (LT5), 90 Corvette (L98).
c. If a clutch fork fails, I would never try to weld or stiffen a clutch fork (the failure is an anomaly) and the heat treatment of the original is unknown.
d. I have seen clutch forks on Ebay as well as complete bell housings with clutch forks installed.
e. Clutch forks do have three wear points (fingers at the throwout bearing, pivot, slave cylinder plunger) all of which should be greased a tad upon installation.
C4 beam plates and Installation (ZF S6 40 Transmission)
For this Installation I am assuming the ZR-1 is lifted and on jack stands on the front and rear or on wheel Ramps/Jack Stands.
1. Advantages of C4 Beam Plates. a. The C4 Beam Plates tie together each pair of bolts (Transmisison pair and Differential pair) with a SS Plate vice aluminum. b. Each C4 Beam Plate also offers a larger contact area of the tensile bolt loads onto the C-Frame. This eliminates the wear on the "C" Frame from a smaller original washer and resulting release of bolt tension. c. The C4 Beam Plate also acts like one big washer wherein the tensile load from each individual bolt is now shared a bit between bolts (minimum effect). d. The C4 Beam Plates correct the condition caused by the bolt holes in the Aluminum C-Frame getting bigger or elongated with wear or the thickness of the Aluminum C-Frame from top to bottom between the original bolt two washers becoming worn so that thickness is less releasing bolt tension. The C4 Beam Plates are definitley worth it if only for the Bolt Load Distribution (Two BIG SS washers on each end) on the C Frame and Ease of Installation. Take Note of the additional Stiffeners on each C4 Beam Plate (The BIG H). There is a BIG Difference between a Clamping Load distibution by two washers and the Clamping Load on ONE BIG PLATE on the Transmission Yoke as well as the Differential Housing.
2. Captured Free Floating Nut Design.
The C4 Beam Plates by Bill Boudreau have Free Floating Captured Nuts on the Top Plate as previously mentioned (which is a bit more complex in manufacture than a welded nut on a plate) This Captured Nut allows the Nut to Float a bit making it even easier to catch with the bolts as you insert them from the bottom.
This Captured Free Floating Nut Concept also allows self equalization of the distance between bolts (as if you are inserting them singularly THE TOP BOLT HOLES ONLY) especially after having one bolt started. The Nuts float and are prevented from turning by the design of the Capture. This Free Floating Capture of the Nuts in the Bill Boudreau Design is more important from an engineering concept (even if only floating on the TOP END) and overlooked by many in this discussion.
From a Structural Point Of View
The Top C4 Beam Plates (ZFdoc) are a little complex in that the Nuts are NOT welded in place but captured and free floating (not allowed to turn). The Bottom C4 Beam Plates are shown in this thread. I have NOT seen any photos of other C4 Beam Plates having that feature. This allows the C4 Beam Bolts to self align without any additional stress from tipping or lateral movement of the two Self Locking Nuts. A very Creative Design from other Load Distribution Designs (C4 Beam Clamping) I have seen
3. Removing existing Exhaust.
The Existing Stock Exhaust is the most difficult to remove. You may need a torch to heat the 6 bolts attaching the exhaust to the Catalytic Converters. I recall the bolts have 15mm Heads. You will need a socket wrench and maybe a cheater bar on the socket wrench handle to loosen the bolts.
A. Once the bolts are removed from the Catalytic Converters the two front and two rear 13mm Head Hanger bolts can be removed. B. Place a rolling hydraulic jack under the rear of the center Exhaust and slide the exhaust to the rear about 1/2 inch to clear the bevel connector on the Drivers Side of the Catalytic Converter Flange Connector. The Front of the exhaust can then be lowered with the hydraulic jack and the entire Exhaust System slid forward releasing the rear slip joints on each side of the tail pipes. Slide the Complete Exhaust System out from under the ZR-1. C. Remove the three lower 13mm Head bolts holding the front Exhaust Hanger so the hanger can be rotated forward and rearward clearing an area for removal of the C-Beam Transmission Bolts.
4. Installation of C4 Beam Plates. a. ALIGN DRIVELINE COMPONENTS: Take the following measurements directly above and to the right of the Propeller shaft front yolk universal joint between the C-Frame and the inside of the underbody. Use a hydraulic jack under the transmission to lift/lower the transmission for proper alignment of the Driveline on the Transmission End. b. To ensure proper alignment of the driveline, a clearance of 45 mm +/- 6mm (1.77 in +/- 0.236 in) must be maintained between the top of the support to the underbody. I set the clearance to 1.5 in to account for unloading deflection when I remove the hydraulic jack supporting the transmission. c. A clearance of 28 mm+/-6 mm (1.1 in +/- 0.236 in) from the (passenger side of vehicle) right side of the support to the side wall. d.Do not use any of the 4 original C-Frame bolt washers on the front (Transmission) or rear (Differential) bolts. e. Tighten support bolts at Carrier (Differential) to 80 Nm (59 lb-ft). f. Tighten support bolts at Transmission to 50 Nm (37 lb-ft). g.Do not go over the Bolt Torque on the Carrier and Transmission or you risk changing the Dimensions of the Carrier and Transmission Connectons.
C4 Beam Plate Installed On Differential......................C4 Beam Plate Installed On Transmission ........................................ ........................................ ..Note C4 Beam Plate Bevel Location
5. Why Take Measurements?
It is kind of a corny measurement since you are measuring between the C-Frame and the side wall/Underbody which is heavily coated and made of light steel and the accuracy of the measurement needs only to be within 1/4 inch + or -. I think you are just making sure you did not put an angle in that front driveline U-joint by moving the transmission appreciably during the installation of the new C4 Beam Plates.
A Quick Measurement in regard to Transmission Yoke height can be checked from inside the car by measuring the height of the Shifter. A height of 6.25 inches from the counsel to the top of the shifter (at the center of the shifter in neutral) will be very close to the correct transmission height.
a. The 1.77 in spacer should fit between the top of the driveline support to the underbody. The 1.1 in spacer should fit between the right side (passenger side) of the driveline support to the side wall. b. You might check that alignment spacing before you start the project to see where your alignment is now. Then just keep that alignment with the installation of the new C4 Beam Plates.
Secondary to Transmission/Driveline Alignment is ground clearance of Transmission Drain Plug. The Transmission Drain Plug clearance to ground is approximately 4 to 4.5 inches on my ZR-1s which is NOT the lowest point on the ZR-1 Drive Train/Chassis. The Ground Clearance depends on many things including Tire Pressure, Tires, Wheels, and Suspension.
6. Re-Installing the Exhaust.
The Exhaust System can be re-installed after the C-Beam Plates are torqued and the front Exhaust Hanger is re-installed in the location of the Front C-Beam Plates.
The Entire Exhaust System can be reinstalled by sliding the Exhaust System under the ZR-1 and setting a rolling hydraulic jack under the rear of the center Exhaust and lifting up to within about 8 inches of the final position.
A. Lift the two rear Tail Pipes and slip the slider into position on the slip joints. Slide the Entire Exhaust System to the rear of the ZR-1 about 1 inch completely engaging the slip joints holding the Tail Pipes. B. Raise the front of the Exhaust System with the rolling Hydraulic Jack to the final height aligning with the Catalytic Converter Connections. Slide the Entire Exhaust System Forward and install 6 NEW SS 10mm x 1.5 bolts. (10mm x 1.5 x 30mm on Passenger Side and 10mm x 1.5 x 50mm on Drivers Side). The SS Bolts shown have 17mm Hex Heads and Washers are NOT required.
SS 10mm x 1.5 x 30mm and SS 10mm x 1.5 x 50mm Bolts
C. Reinstall the two Front 13mm Head Hanger Bolts and the two Rear 13mm Head Hanger Bolts.
7. Questions/Answeres Originally Posted by Hammer Regarding C4 Beam Plate Installation. a. Exactly where do you check the alignment? I checked between C-Frame and side wall/underbody at location of C-frame bolts (transmission extension housing). b. Do you jack the transmission towards the upper and right tunnel to get the alignment right? I placed jack under transmission (with a little upward pressure) BEFORE I loosened C-frame bolts. c. Do you tighten the back differential bolts and then check alignment? I installed the C-Frame Plates at the rear (differential) first after placing a jack with a little pressure under the transmission (but not loosening the transmission extension C-Frame bolts). I tightened those differential C-Frame bolts and then moved to the front of the C-Frame (transmission extension housing). d. Are all the bolts just snug and then you check alignment? That is the idea......but on mine I tightened them up and found that the alignment was perfect anyway since I did no jacking or moving of the transmission after loosening the C-Frame bolts. And, since I did the differential C4 Beam Plates first. e. Do you use red or blue locktite on the threads? I used blue Loctite since I might recheck from time to time. I use blue Loctite on anything I think I will recheck such as the Plenum bolts for example. Red loctite on the starter bolts, and the crankcase ventilation cover for example. Blue loctite on the oil pan and red loctite on the the oil pickup and baffle within the oil pan for another example. f. Do not use the 4 original C-Frame bolt washers on the rear (Differential) bolts. Use 2 of the 4 original C-Frame bolt washers on the front (Transmission) bolts as they were originally. The Tranmsmission C4 Beam Plate beveled corner faces toward the front of the transmission.
8. Caution on Jacking the Engine. Always remove the C4 Beam plate bolts on the transmission yoke when jacking/lifting the engine to minimize potential of twisting transmission yoke or C-Frame. .
FRONT........................................ ..............................REAR
Nitto NT 555 Extreme Performance..................................Nitto NT 555R Drag Radial
P275/40ZR-17 98W........................................ .............315/35R-17 102V B ........................................ .....................
1. Total for ALL four tires (two FRONT and two REAR) $666 with free shipping. 2. Tires arrived 3 days by UPS after ordered from Discount Tire 3. Took new tires and two sets of rims with original good tires and old tires to local WW Tire 4.WW Tire removed original good tires from A-Molds and installed them on another 1990 ZR-1 (#3032) with original SawBlades then installed new Nitto tires on 1990 ZR-1 A-Molds (#2067). 5. Cost to install ALL tires including balancing was $20 each tire (including removing a nail from one original tire). 6. Confirmed tire balance at 135 mph on both ZR-1s with zero vibration at any speed 0 - 135 mph. 7.WW Tire installation was Absolutely the best balanced tires I have ever had. 8. Tires (some helpful hints from Marc Haibeck) a. There are four or more brands available for the ZR-1. Sumitomo, Kumho, Nitto, Vredestein, etc. b. Sumitomo's may flat spot when cold because there is one nylon cord. They will thump for about the first five miles when cold. c. Kumho's racing tires are excellent. d. The Nitto NT 555 provides 95% of the performance of the Goodyear D3 at about 60% of the price. The soft thread on the NT 555R wears out in about 20k miles. e. The Tire Rack does not sell Nitto. Discount Tire has them Discount Tire. f. AFS Wheels sells Vredestein tires Vredestein. AFS Wheels are the same as "Cleanin-out-the-garage" on Ebay. Cleanin-out-the-garage has Lots of information on Vredestein Sessanta tires on Ebay Vredestein Tires.
Seethis from Captain Z
Please take a moment to inspect the small metal gear located on the top of the shock. Often they are broken and must be replaced before the fx3 system will be restored to working order. We have original equipment gears in stock for 1989 to 1991. We have replacement gears for 1992 and later models in stock also. These gears are made of steel finished in yellow zinc dichromate. There are two different gears used on the shocks in the fx3 system. The difference is in the size of the stop located along the lower edge of the gear. The year of your Corvette determines the type of gear used. See photo below.
Visually inspect the gear for breaks and for cracks. Also the gear should not be able to turn in complete circles without stopping. If you can turn it continuously without hitting the stop then it is broken and must be replaced. The gear can be replaced in either position without affecting the operation of the shock.
From this it appears to me the setup of the FX-3 is self aligning in all regards...........just want to make sure.
Originally Posted by Dynomite
Got a new front actuator on Ebay and installed it with shock gear centered. Appears the positon of shock gear makes no difference because the actuator does a self alignment on startup. Got rid of Service Ride Control warning ......it went away immediately and never returned
Seethis from Captain Z When the ignition key is turned, the system will do a check to be sure it is working properly. The service ride control light should come on momentarily and then go out if all is well. If the light stays on then the system most likely has problems.
The two following observations suggests FX3 Bilstein self alignment IS what I think it is........
Originally Posted by We Gone
I've had my front actuator motors off every time I clean the front suspension, blow the grit out of the cups and put a drop of gun oil on the shock gear even turn the gear and never paid attention to the position when I put them back on with 0 issues.
Originally Posted by Jagdpanzer
I changed out my front shocks recently and all I had to do was carefully reinstalled the actuator by rotating it back and forth as it went down on shock the to make sure the actuator and valve gear teeth properly engaged. When fully inserted the splines on the outside of the actuator cap will lock into the metal cup on top of the shock and the retainer clip will insert easily then. As mentioned above when you turn the ignition key on the actuator cycles in both directions sensing the location of the valve hard stops by the resulting increase in current draw when the stops are reached. Then you’re ready to go. If for some reason the control system cannot find either of the valve hard stops (in case of broken gear) or senses the calibration time is taking too long it will trip the “Check Ride Control light”.
07-12-2012, 11:23 PM
LT5 Camshaft Specifications and Camshaft General Timing (pinning)
) on how to reset a timing chain tensioner with some good instructional pictures. It was done by someone with a forum name of ZR1 at that "other" forum. I decided to go looking for it since I need to reset my tensioners. Resetting timing chain tensioner TIPS 
