Speedometer problems
 

When I bought my truck, the speedometer did not work. So I tried replacing the
cable, to no avail, and then the speedo itself, from a junkyard still nothing. Could it be the speedo driven gear? If so where can I get one? Schucks and autozone, etc say that they do not sell them?

Btw its a 1977 C10 with a 305 and a 350 a/t tranny

Re: Speedometer problems
 

probably the gear if you replaced the other 2. have the tires been changed? When you change the speedo gear to compensate for tires, you have to move it so it'll mesh since different gears have different diameters, it miay not be where it should be.

Re: Speedometer problems
 

I bought the parts for mine locally at a transmission supply shop. It is the place the local rebuilders get their stuff. It was cheap.

http://slonaker.net/images/truck/speedo1.jpg

Slonaker

Re: Speedometer problems
 

No tire change whatso ever....

Re: Speedometer problems
 

hello,,had a problem like that too...i THOUGHT the cable was in the back of gauge cluster all the way and it was clipped in properly,,,"i thought" after a week i figured out i thought wrong,,lol thing's just were not connected all the way...:)

Re: Speedometer problems
 

Slonaker I believe my gear drive is broken as well. I have a4 speed with granny, 2 ton clutch and have 16's for tires. I don't know anything else spec wise on the tranny. Did the transmission shop look it over to figure which drive gear you needed or did you already know? All of my trans. shops dont have a clue or maybe it's just me.:confused: :drama:

Re: Speedometer problems
 

Take the one you have out and see if there's anything left of it that could tell you tooth count.

Re: Speedometer problems
 

On my 85 C20 454 4 speed the transmission has a "gear drive" or reducer which is external to the transmission. The shaft that runs between the speedo cable and the transmission gear failed. It was in this housing. These are different for the different rear end ratios and tire sizes.

LILREDGMC