New Tach cable not working
04-14-2012, 08:08 AM
#21
Safety Car
I don't see that anyone mentioned this--start the car with the cable and housing unattached to the distributor, and take a look at the shaft inside the large threaded coupling. If its not turning, then you have gear issues. If it is turning , you have an issue with the tnterface between cable end and shaft end when you install the cable.
04-14-2012, 10:10 AM
#22
Former Vendor
Member Since: Aug 2006
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
If you know the dash unit is working (hook drill up to cable and see) I'd pull the distributor and go looking for the problem.
There are many factors that can cause the cross gear to not mate up with the main shaft and be destroyed...
On distributors made from 1962-1969 the wall of the distributor housing would wear out as shown in the picture below. Staring in mid production 1969 GM added a Teflon bushing and a hole in the distributor wall to prevent this. (pictured below)
If the Teflon bushing fails or falls out the cross shaft will not align with the main shaft.
If the Teflon bushing fails or falls out the cross gear can also wear into the back housing of the distributor.
On 62-69early distributors the gear will wear in the housing as shown below.
The coupling can also be a problem area for the distributor. If you look at the picture below you’ll see where the cross shaft surface has worn in to the coupling which will allow the **** outward and not align with the main shaft.
Distributor shaft upper and lower bushing wear can be another cause... Upper wear will tear up the teeth quick. A quick test to see if the distributor upper bushing is shot is to hook up a dwell meter and rev up the engine. If the dwell changes with RPM increase the upper bushing is bad.
The best advice I can share with you is to remove the distributor and start looking for issues in the above area's.
Willcox
There are many factors that can cause the cross gear to not mate up with the main shaft and be destroyed...
On distributors made from 1962-1969 the wall of the distributor housing would wear out as shown in the picture below. Staring in mid production 1969 GM added a Teflon bushing and a hole in the distributor wall to prevent this. (pictured below)
If the Teflon bushing fails or falls out the cross shaft will not align with the main shaft.
If the Teflon bushing fails or falls out the cross gear can also wear into the back housing of the distributor.
On 62-69early distributors the gear will wear in the housing as shown below.
The coupling can also be a problem area for the distributor. If you look at the picture below you’ll see where the cross shaft surface has worn in to the coupling which will allow the **** outward and not align with the main shaft.
Distributor shaft upper and lower bushing wear can be another cause... Upper wear will tear up the teeth quick. A quick test to see if the distributor upper bushing is shot is to hook up a dwell meter and rev up the engine. If the dwell changes with RPM increase the upper bushing is bad.
The best advice I can share with you is to remove the distributor and start looking for issues in the above area's.
Willcox
04-14-2012, 12:32 PM
#23
Melting Slicks
Member Since: Aug 2008
Location: Lehigh county Pennsylvania
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You failed to mention how you corrected this little problem. You cannot possibly expect the tach to work if that bell with the threaded connector is not on the cable sheath.
