The speedometer in my new (to me) 1970 Corvette (300ci) manual trans, wasn't working. I looked into it and found that the speedometer cable was disconnected from the transmission, which seemed like an easy win, but of course nothing is ever that simple.

I was able to reconnect it and hand tighten, but I couldn't get pliers in there to tighten it further. Is there a better tool I can use to fully tighten the cable to the transmission? The cable connects to the trans on the passenger side right above the transmission mount at the cross member, which makes it difficult to get to.

If there is no good tool, then I thought of two options. I could remove the exhaust pipe clamp above the transmission mount to get better access. Or I could remove the speedo bullet from the transmission (I might have better access to that bolt) and tighten the cable while the bullet it out. Do either of these sounds like good options or has anyone done this before?

And, to keep things interesting, I found that the cable was rubbing against the exhaust pipe which melted away a portion of the cable. The metal mesh in the cable was still intact, so I wrapped it in electric tape as a temporary measure. Should I replace the cable now or wait until it becomes a problem?

The cable was rubbing against the exhaust because it looks like the metal clamps/brackets that held it above the pipe had rusted away. I was able to zip-tie it back up above the exhaust to one of the pieces of metal that was still intact. Has anyone replaced these brackets before? Would I need to remove the rivets and then screw in new brackets?

Thanks !

 

Addressing the cable connection to the trans: the cables I've worked on only had/have a knurled ring to grasp as you tighten or loosen the connection. Because of the design of this, a wrench or pliers is not recommended; hand tighten and leave it at that. Seems to me that it was intentionally disconnected as I've not heard of them unscrewing themselves. Is your speedo working now that it's reconnected?

 

hand tighten usually is enough to need pliers to remove, unless you have arthritic fingers....Im heading that way. If you must use pilers slip some rubber hose over the jaws to prevent damage aadn just give them a gentle tweak. It just needs to stay on, the bullet has an oring to prevent seepage

 

Thanks all. I took it for an hour drive this morning and the speedometer worked the entire time.

I'll check out how the tape and zip tie is doing next time I raise the car.