Tach not working

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Sep 1, 2016 | 11:17 AM

sportster89

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From: Bradenton Florida

Tach not working

I have a 1974 and do not what to check to see whats wrong. If I spin the cable dis.end the tach moves. What should I try next? Thanks

Sep 1, 2016 | 01:06 PM

antfarmer2

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Quote:

Originally Posted by sportster89

I have a 1974 and do not what to check to see whats wrong. If I spin the cable dis.end the tach moves. What should I try next? Thanks

Better off in c3 section but would clean the wire connections on the distributor.

Sep 1, 2016 | 10:51 PM

sportster89

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From: Bradenton Florida

Quote:

Originally Posted by antfarmer2

Better off in c3 section but would clean the wire connections on the distributor.

I do not know how I posted on C4 I have to pay more attention. Thanks

Sep 2, 2016 | 12:20 AM

Cliff Harris

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From: Anaheim CA

On my '71 the shaft gear was worn out inside the distributor.

This is not my car but this is exactly what mine looked like:

http://s167.photobucket.com/user/Cav...n6vhn.jpg.html

Last edited by Cliff Harris; Sep 2, 2016 at 12:24 AM.

Sep 2, 2016 | 08:21 AM

Joe C

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Quote:

Originally Posted by Cliff Harris

On my '71 the shaft gear was worn out inside the distributor.

This is not my car but this is exactly what mine looked like:

http://s167.photobucket.com/user/Cav...n6vhn.jpg.html

also, check the "squareness" on the cable end that mates with the drive gear. most likely it's an issue with the drive gear internal to the distributor. on my 69 SB, seems to me I had to replace my drive cable. I also added a bronze button as surface bearing on the drive gear end during my distributor rebuild.

, needs to be moved to the C3 section.

Sep 2, 2016 | 10:07 AM

Streamline

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From: New Hampshire

Had the same problem on my 72. The path of the tach cable into the distrubutor was poorly engineered.
Bought the 90 degree tach drive cable adapter..no more problems.

Sep 2, 2016 | 11:23 AM

Joe C

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Quote:

Originally Posted by Streamline

Had the same problem on my 72. The path of the tach cable into the distributor was poorly engineered.
Bought the 90 degree tach drive cable adapter..no more problems.

no, it was correctly engineered. no flames, but some people get in there, screw around, and have the distributor indexing off by one or more teeth on the drive gear, and think they need some aftermarket adapter to correct GM's poor engineering. if the distributor is properly installed, the tach drive cable comes off, approximately 90° left of the engine's centerline. the tach drive cable comes off the distributor, makes a smooth 90° transition, thru the dash and to the tach. those 90° adapters were just a band-aid for poor maintenance and engine assembly techniques, not to fix GM's screw-up.