1970 C10 Speedo Cable Replacement

[rmawyer]

Speedometer needle skipping. Truck has a 68 inch cable that goes from speedometer to a coupler (maybe for cruise control?) in engine bay. There is a second lower cable from same coupler to transmission that is about 55 inches long. Home mechanic friend used drill to show upper cable working; subsequently determined lower cable is broken, needs replacement. Not having any luck on tracking down a replacement cable. I may not be using the correct cable name in my online searches. Any ideas on where to look? Also, is the cable unique because of the cruise control? As always, thanks for any insight shared.

[ncpetersc]

https://www.summitracing.com/parts/o...del/c10-pickup

Maybe?

Don't know what engine/tranny you have, but the length of this matches what you are looking for.

[rmawyer]

Thanks for the information and confirmation, since it matches one I was finally able to locate on the JEGS site. I still don't know if the cruise control matters, but I took a chance and ordered the part anyway.

[ncpetersc]

Originally Posted by rmawyer

Thanks for the information and confirmation, since it matches one I was finally able to locate on the JEGS site. I still don't know if the cruise control matters, but I took a chance and ordered the part anyway.

I think cruise/no cruise may just change the length.

[rmawyer]

Thanks for responding!

[rmawyer]

I replaced the lower speedometer cable and still have same symptoms: needle skipping, sometimes stays at 0 MPH, never goes higher than 20 or 30 MPH. I've been told there are 4 major parts involved - the speedometer, the upper cable from the speedometer cable to an engine bay coupler, the lower cable from the engine bay coupler to the transmission, and a plastic (?)gear in the transmission. Since I replaced the lower cable with no improvement, and I have a replacement upper cable, should I try that next? Again, thanks for any advice.

[rmawyer]

Here's the latest. Took truck to a mechanic. He said the coupler / transducer needed to be repaired or replaced, since one of the receptors for a cable had become rounded. Even though I'm not hooking up the cruise control for now, I found a transducer replacement. Now I'm going to connect the two cables to the transducer. Here's my challenge - trying to find a GM cable roughly 36 inches long for the speedometer to transducer without having to make a custom cable. Anyone know where I can get one? No problem getting the lower cable. If this does not fix the speedometer issue I'll next replace the transmission drive, driven, and speedo gears. Thanks.

[demian5]

Originally Posted by rmawyer

Here's the latest. Took truck to a mechanic. He said the coupler / transducer needed to be repaired or replaced, since one of the receptors for a cable had become rounded.

Why not put a small amount of some tin foil on the end of the cable and shove it in and see if it works?

[rmawyer]

Thanks for the suggestion.