ok still have a speedo prob. first it was the needle jumpin5 to 10 miles at any speed changed the long cable tested the short one it looked go hook it up (not fun place to b i might add) took it for a spin the dam thing worked like a new one for about 4 miles now nothingi wonder if the cop will understan

 

I doubt it.

 

There's an app for that.

Don't ask how I know. ;-)

 

so what do u think is wrong with my speedo

 

It only works when it feels like it.

 

Sounds like the female square drive in the speedometer might be worn out. Can be easily pulled from the front and checked. Remove the clear cover over the speedo and tach and unscrew speedo mtng tabs. Unhook cable from backside and remove speedo out the front. If square drive connector is worn cable will slip causing needle to jump and eventually stop.
Just a guess but fairly easy check. Good luck.

 

I would say it is the gear on the end of the cable that is right inside the transmission that is stripped out. The worst case scenario would be the gear inside the transmission that is bad (like mine) this is not working and strips out the gear that is at the end of the cable.

 

If not at the speedo look at gear drive in tail of ur tranny.

 

thanks i'll check that

 

Dave..

On your car it makes the job way easier (and less up-side-under) to remove the dash housing to replace the cable. If you do it this way... you can remove the cable from either the transducer or the transmission (if no cruise) and pull the housing outward, reach behind it and un-clip. Then reverse to install.

Before I removed anything and if you have cruise, pull the cable loose at the cruise transducer and hook up a drill to it and see if your speedo is working.. If it is working by doing this the problem is lower… Transducer, lower Cable or Drive gear. I would then do the same at the lower cable by the tranny.. spool it up with a drill and see if the speedo works. If it works the issue is in the tranny gear. If it fails to work I’d inspect the transducer, the lower cable.

Failure in the 1978-1982 speedometer is very far and few between. The head style changed in 1978 and the newer design seemed to solve an age old issue with the failing first worm and magnet issues. Funny two post today with the same problem…


Side Note: And just to add to this… If you ever find a tip broken off the speedo cable when you remove it.. always remove the broken off end from the speedo (or transducer). Sometimes it is possible to get the cable on the gauge with the excess still in there but in most cases this will bind up the speedometer speed cup. (long story here).

If you ever have a broke off tip (and it’s the plastic design) removal is easy. Find some decent size wire.. (for us we use Bowden wire or the same wire used for making the heater/ac pull cables and also used on lawn mower throttle cable). Cut off a section about 12” long and then heat it with a torch until it is almost glowing… Insert this in the end of the speedo and then let it sit until cool. When cool pull the broken end out of the gauge.