C2 tach needle bounce

[brumbach]

65 vette w/327. I get a lot of needle bounce in my tach when rapidly accelerating. Works fine otherwise. Don't have the orginial distributor. Using a dual point mallory with mech tach drive. Any suggestions as to correcting this problem? Bill

 

[allcoupedup]

Lube that cable!

When the grease dries out in the casing, the tach cable faces resistance and has trouble accelerating as fast as the tach drives it so it ends up acting like a spring. It winds up, un-winds, winds, un-winds.... and that is why your tach bounces all over the place.

I need to do the same thing to mine. If I'm in first and I bring it to redline, the tach will track just fine until I shift, since the RPMs drop rapidly, the tach cable cannot adjust so it winds up and starts bouncing all over the place. Does this when I rev the motor too.

You can buy special lube - some have used other forms of lubrication - not sure what works best.

Brian

 

[maxphunn]

"You can buy special lube - some have used other forms of lubrication - not sure what works best."

From what I remember, the special tach cable lube won't "creep" into the tach.
This might be some of the General's hype, but I got some of the special lube for mine just in case.

Pat G.

 

[studiog]

You might want to also check that there are no sharp bends in the cable. Allow as gentle an arc as possible.

 

[brumbach]

As I said, I don't have the correct distributor. The mallory has a grease fitting on the base of the shaft (flip side of the tach cable connection). Would greasing this fitting help? Bill

Lube that cable!

When the grease dries out in the casing, the tach cable faces resistance and has trouble accelerating as fast as the tach drives it so it ends up acting like a spring. It winds up, un-winds, winds, un-winds.... and that is why your tach bounces all over the place.

I need to do the same thing to mine. If I'm in first and I bring it to redline, the tach will track just fine until I shift, since the RPMs drop rapidly, the tach cable cannot adjust so it winds up and starts bouncing all over the place. Does this when I rev the motor too.

You can buy special lube - some have used other forms of lubrication - not sure what works best.

Brian