Tach drive

[William G.]

The gremlins keep cropping up in my 67. After 8 months of dealing with almost daily problems putting the original matching numbers engine back into my 67, I finally got it fired up today. However, the tach does not work! The cable is inserted into the back of the distributor gear, which was rebuilt by Dave Fiedler. Previously, as in last spring, when I removed the engine that was in the car, the tach was working fine in a different distributor, ( old Mallory Rev Pole ). Anyone have any suggestions?

Ratracer

[Don H.]

Re: Tach drive

It is possible the cable is a little short and came out on one end. I would remove the distributor end (much easier to get to) and verify the drive is turning in the distributor. You can then run the cable with a drill to verify the tach end. Good luck, Don H.

[William G.]

Re: Tach drive

Before dropping the distributor in yesterday, I did check to make sure the distributor gear was turning. It was. Could be that it has come out of the tach end though, as it was sticking out of the distributor end of the cable an inch, or so.

[Joe L.]

Re: Tach drive

Before dropping the distributor in yesterday, I did check to make sure the distributor gear was turning. It was. Could be that it has come out of the tach end though, as it was sticking out of the distributor end of the cable an inch, or so.

William------


On the instrument end there is a collar which prevents lateral movement of the cable. In fact, that's the reason that the cable cannot be removed from the distributor end.

[Don H.]

Re: Tach drive

Joe, you are assuming it is the correct cable and was installed that way. I would try the using a drill on the distributor end.

[Joe L.]

Re: Tach drive

Joe, you are assuming it is the correct cable and was installed that way. I would try the using a drill on the distributor end.

Donald------


I agree. Using a drill to try to rotate the cable is the first thing to do. If the tach doesn't operate, then he has to go into the dash regardless. He needs to make sure the drill is operated in the correct direction (I've forgotten which is correct).

[John H.]

Re: Tach drive

Donald------


I agree. Using a drill to try to rotate the cable is the first thing to do. If the tach doesn't operate, then he has to go into the dash regardless. He needs to make sure the drill is operated in the correct direction (I've forgotten which is correct).

Joe -

The drill needs to run in reverse (so the cable runs counter-clockwise as viewed from the front of the car).

[Joe L.]

Re: Tach drive

Joe -

The drill needs to run in reverse (so the cable runs counter-clockwise as viewed from the front of the car).

John-------

OK, thanks. I kind of thought it was reverse but I wasn't sure enough as getting it wrong might cause tachometer damage. I'll try to remember that now.

[Jerome P.]

Re: Tach drive

John,

I am hoping I don't need to get under the dash and my problem is at the disributor (faulty cross rear)

I am going to test my tach cable to verify that the tach does turn when connected to a variable speed drill.

Procedure: I understand the variable speed drill is set in reverse. However, is there a recommended drill speed (very slow, slow, medium, fast) I should use to verify if the tachometer is turning and functioning properly?

I obviously do not want to over spin the tach.

Thanks in advance for your thoughts.

[Mike E.]

Re: Tach drive

Unless you have a drill on steroids, it can’t turn fast enough to hurt the tach. 6500 rpm on the rach would be 3250 on your drill. I would use multiple speeds to see how the tach responds, if it does.

[Michael F.]

Re: Tach drive

unless you have airco car getting to tach on back is no big deal, just a little tight to move hand around up there, done many times, good luck and take your time

[Jerome P.]

Re: Tach drive

It is a LT1 car with factory A/C. Exponential harder to get to back of tach.