aubinw

I have a 68 Coupe with a 302 and a C4 transmission. I've been having speedometer problems for a while and I was wondering if anybody here has ideas about what is going on. I replaced the speedometer cable a couple of months ago, then finally figured out that the gear was broken and I replaced the gear. After replacing the gear, the speedometer worked for about a mile and then quit working. I pulled the gear out of the transmission and it looks fine. I pulled off the instrument panel and disconnected the cable and drove down the street. The cable spins just fine. However, when I stop and hook the cable back up to the speedometer gauge, then start moving, it starts clicking in the back of the gauge like the cable is still spinning but the gauge is not turning. Also, the end of the speedometer cable that goes into the gauge now looks kind of chewed up. Do I need a new gauge? I wanted to ask around before I purchase one.

Gun Jam

prolly a crap chicom cable. Do you still have the one you pulled out?

aubinw

Nope. It's long gone. I don't remember where I ordered the new one. Any suggestions?

Gun Jam

maybe hit up ebay for a new old stock cable. Maybe someone online has a collection of old mustangs and can get you a used original cable.

Gun Jam

obviously you'll want to install the cable in the speedometer first and rotate the gear end by hand to insure that it does indeed rotate smoothy. Any resistance and you may want to replace the speedometer as well.

aubinw

Yeah, I'm going to work on that this weekend when I have a little time. Thanks for the advice. I'll let you know how it pans out.

bop11

As gun jam said maybe a poor cable. The speedo end may be too short and only fit into the meter a short distance. There is usually a clip on the end to keep the end sticking out of the shielding a specific distance. This can move, making the end not penetrate the meter far enough and finally rounding it off.
The bearings in the meter could also be bad causing the rotating cup to grab and not run smoothly. This usually results in the needle not moving then moving a to a high sped and then back to nothing over and over.

aubinw

Thanks guys. I found a poor old rusted out 68 in a junkyard and pulled some parts off of/out of it this morning including a speedo cable! This cable has the little copper ring/clip on it to keep the cable engaged into the back of the gauge. I'm putting this cable into my car now. I'll let you know how it works out. (Just in case it's the speedometer gauge itself, I also pulled the instrument panel out of that poor old car).

aubinw

Here are the ends of the two cables. The old cable out of an original 68 is on the right. The new one that I've been having problems with is on the left. Note the dramatic difference in the length of actual cable sticking out between the two. Hopefully this will solve it.

aubinw

It worked! The old cable that I pulled out of a junked out 68 mustang in a junkyard works perfectly. I put a new gear on the end of it and threaded it through the firewall. No problems at all! Thanks for the advice!!