hey all. i have a 65 mustang. the speedometer is original and when im driving and givin it gas ... the speedometer moves up and then the needle juss goes crazy up and down like if its loose or something.. like up to 20 mph it kinda accuarate, then aftet hat it goes nuts ....any suggestions?

 

My guess would be the drive gear at the end of the speedo cable where it inserts into the trani. The gear teeth are prob worn. Its a cheap part to replace and most vendors have them. Good luck.

 

I got the same problem with a new gear drive at the trans end of the cable.

and it's intermittent to complicate matter.

My guess is it's the speedo itself in the gauge cluster.

 

if i get underneath the car, where exactly can i find that cable?

 

It will be on the passenger side right by the trans mount. Pull it out, and pull the clip off and spin the cable on a drill. This will tell you if it;s the gear, or cable. Everytime I've done one, it's the cable.

 

Sometimes speedo cables can "stick" in the sheath, so what happens is the cable "winds up" like a rubber band on one of those rubberband powered airplanes, then it will break loose, when it breaks loose it will often make a strange noise, and the speedometer needle will jump arround.

Try oiling the cable and see if that helps...

 

Needs a new cable

 

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Probably the cable is the root cause, and a binding cable will cause the driven gear at the end of the cable to shed teeth.

But before simply replacing only the inner cable, make sure the outer sheath isn't damaged.A sharp kink, crushed place, or torn spot (leak) will ruin the new cable pretty quicky too.


Norm

 

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