Puzzled

[Gary S.]

I cannot get my tachometer in my '67 Corvette to work when everything is connected. When I purchased the car it had an after market Tach housing and cable that was 2.5 inches shorter than an original assembly. The tach worked, but since the housing was considerably shorter it put the tach in a bind causing it to make a noticeable noise. I installed an original cable / housing and the tach would not work. I thought that mayne the cable was too short so I had a cable made 1/4" longer. Still no luck. If I disconnect the cable from the tach and start the engine, the cable moves fine and you cannot stop it from turning. I can install just the cable in the tach and put a drill motor on the cable and the tach works fine. I can install just the cable in the distributor and tach and the tach works fine. I purchased another tach housing and cable assembly only to get the same results. Everything works fine until I screw the tach housing on the tach. I have reversed the tach cable knowing the washer end goes toward the tach, but it still will not work. Im out of combinations and patience. Any ideas.

[Carl N.]

Re: Puzzled

Disconnect at dist and have someone turn cable while you watch tac ?

[Bill M.]

Re: Puzzled

this is probably not the solution. But I had problems with my tac erratic readings and I finally found out that the distributer shaft gears were worn.

[Gary S.]

Re: Puzzled

New gears in distributor. Cannot hold the cable from spinning while engine is running. Thank you for the suggestion.

[Gary S.]

Re: Puzzled

Tried this with a drill motor. Tach will not work. It has something to do when the cable housing is connected to the tach, but I do not see any issues with the tach head assembly, cable, or housing. Thank you for the suggestion.

[Bill S.]

Re: Puzzled

You have tried a new cable, a new housing, everything works until you connect the cable housing to the tach then it stops. Problem is in the tach then. Maybe something got off center in there and when you screw the cable on, then it binds. If the cable is loose it has enough slop and can still turn the tach.

[Gary S.]

Re: Puzzled

I agree that the problem is in the tach. My next move is to remove the cluster to get a good look at the tach. If I don't see any issues I will send it off to have it checked out. I'm out of ideas. Thanks for trsponding.

[Steven B.]

Re: Puzzled

Just out of curiosity, have you tried loosening the threaded collar that attaches the casing to the tachometer housing and then spinning it with a drill from the distributor end? I wonder if something is pinching the cable. If it spins with the collar loosened, then something is preventing the portion of the tachometer where the squared end of the cable inserts from turning freely when the collar is tightened. Just a thought.

Steve