So among the many things my new project needs, one of them is the speedometer. The previous owner told me it used to be intermittent, but appears to have stopped working completely since. I've been using Ulysse on my phone for speedometer purposes, but that's definitely a temp fix. Now to my understanding the speedometer gear should be in the back of the tranny, correct? I've been having a hard time finding answers through google for this. I have the C6, is it in the tranny itself or on the drive shaft somewhere? Idk the technical terms but mine has the tranny that hooks to a smaller shaft that's hooked to a larger one that goes all the way back. Is this something I could do by myself in a day?

 

Find the cable going into the tail shaft housing on the trans. The driven gear is on the cable just inside the case, and comes out when you pull the cable. It will be clear once you get to it how it comes out. IIRC, held in with one bolt and a metal keeper.

If the gear is good, check the cable itself. Does it turn, does it make it all the way to the speedo.

If the gear is good and turns the cable all the way to the speedo, it's the speedo.

I think you might find it's the cable. Much more common to have those fail than the speedo.

 

Take the cable off THEN take the keeper and the little round barrel housing out. You will then see the plastic gear.

If the gear looks ok, get someone to watch the speedo as you twirl the gear with your fingers(put the cable back on temp with the barrel out). If should turn smooth and the speedo should jump up. Sometimes you can put a drill on it and get it to read if you like.