I have a 1980 Corvette. The lower speedo cable between the transmission and the cruise servo burnt on the exhaust pipe and broke. I replaced it but the speedometer still does not work. Help......what do I look for next?

 

Welcome to the forum.

Disconnect the cable from the speedo at the servo and spin it and see if the speedo needle moves. If it does then pull the speedo gear from the tranny and ensure that it's OK. See if spinning the cable at the tranny end causes the servo output side to turn.

IOW, you need to isolate where the problem is.

 

I have a 79. My speedo wasn't working when I bought it 3 weeks ago. It's usually a broken cable but that wasn't the case with mine. I found the gear in the auto trans tailpiece had slid forward on the shaft so it wasn't in contact with the speedo drive gear. I had to remove the driveshaft and tail piece for access to the gear. I found nothing broken inside nor any way to keep the gear from sliding forward or back on the shaft. There is a pin that lines up with a slot in the gear to make it turn with the tailshaft but there are no grooves for a snap ring in front or back of the gear. I ended up using a worm gear hose clamp on each side of the gear to keep it in place. Placed the screw part of each clamp 180 degrees apart from each other for balance. It's been working fine since.

 

Welcome to the forum.

Thanks for the info. Wonder if the drive gear is just pressed on and yours was out of tolerance.

 

Its possible it may be pressed on. Mine is a snug fit and not easily moved by hand on the tailpiece shaft but it does move. After I slid it back into position it was fine for about 50 miles then it stopped working again. Pulled apart the second time and found it had moved again. That's when I decided to use hose clamps to keep it in place. This may or may not be Chubbs325 problem but figured I'd let him know what mine was.