Tachometer cable and gear question

[Peter B.]

Well, for the past 6 years I have not had a Tach. Cable was disconnected off of the Distributor when I bought the car. Tonight, in preparation for ordering the parts I need, I took the Coupler out. As expected, the gear I extracted was pretty eaten up. I guess I need to clean out where the coupler came from on the Tach stem. I do not want to take the distributor drive out, so any recommendations on this would be appreciated.

One thing I noticed is that when I connect the tach cable to the coupler, the square rod that rotates does not seem to reach far enough into the torn up grear to rotate it. My Tach cable's little square drive rod seems to be too short or broken. Anyone have any idea how long it should stick out when they are new?

Any other tips would be greatly appreciated.

Best Regards

Peter Bouza

[William C.]

Re: Tachometer cable and gear question

About 1/2 inch past the end of the flange should work fine. the bad news is that if the crossgear is torn up, the drive gear on the dist shaft is also gone, and the issue that caused the problem is still with you. Normally this problem results from the crossgear eating it's way thru the cast iron case to the point where the gears no longer mesh properly.

[James W.]

Re: Tachometer cable and gear question

Bill,

On a C2 Corvette, will a worn tach cable cause the tachometer/pointer to jump or oscillate when the car is idling? It works fine and does not oscilate whwn driving around town and on the highway. From what I can tell, the cable and sheath are the originals that came on the car when I bought it in 1979.

Thanks,

James West
Omaha, NE.

[William C.]

Re: Tachometer cable and gear question

I have no experience to judg that on. replacing the drive cable, not the sheath is a relatively easy way to find out if it cures your problem.

[Jim T.]

Re: Tachometer cable and gear question

Peter I have replaced a two tack drive systems but cannot give any better information than that which is available from www.tispecialty.com. A rebuild of our distributors is expertly covered. If you inspect the upper lubricant cavity in your distributor, you could find dried up remenants of lubricant. The longivity of the crossgear tach drive system is lubrication and this is not mentioned in service or owner manuals that I know of. You said that you do not want to take the distributor out, you must to properly put this unit back in operation. It is not really that difficult.