brucep

The speedo cable in my 66 M-21 broke. The replacement cable was a lot longer than the one I broke. I get needle bounce at slow speeds with the replacement cable. I've been told this happens when a cable is too long and must be crimped to fit. Can anyone tell me the correct length of an original 66 M-21 speedometer cable?

Thanks

gbvette62

65-67 4 speed Corvettes used a cable, approximately 71" long. 63 and 64's, used a much shorter, 57" cable.

The 65-67 use a longer cable, because it attaches to the right (passenger) side of the tail shaft. On earlier 4 speeds, the cable goes into the left side, so the cable is shorter.

3 speeds and automatics, use a 60" cable.

66since71

Doubt it will make much difference, but...

I replaced my original tach cable/jacket assembly last fall. Apparently, whoever munfactures these things for the usual suppliers took Chevy specs for length of the cable itself and applied it instead to the jacket, less end fittings, so the new cables wound up about 4" too long. I tried several suppliers: all the same. I wound up going to Bob's Speedometer in Howell Michigan, where they duplicated my original. I'd be surprised if the 4" would make a big difference on the speedo cable, but stranger things have happened.

Harry

Edit, if you jacket is in good shape, you should be able to get just a new cable?

DZAUTO

Why BUY a new cable???
Just cut off the excess of the cable that's too long, take the cable to ANY speedo shop and have them stamp the end square. ANY and ALL speedo shops have the stamping die to square a speedo cable. I even have one in my tool box.

Nowhere Man

Tom local speedo repair shops are tough to find its like going to a auto parts store and getting heater control cables made up. Its a thing of the past.