Re: Speedometer cable

Posted by Packard Don On 2019/11/12 16:20:50

If the speedometer needle is jumpy, it is often due to a sticking cable but whatever is causing it, letting it go too long without lubrication will eventually lead to breakage of the cable. The cable acts as a torsional spring that winds tight when something is binding. If the bind is not absolute, once enough torsional force is there, it breaks free and the needle jumps and the process starts over. If it is absolute and no amount of force can free it, then the cable will twist until it breaks.

Since it's relatively sealed, a little oil or light grease is fine and I even once made an adapter to use from the transmission end to push grease up into it rather than trying to do it from above. I used it only once but it worked well and no more jittery needle even today. Of course, it's also important to oil the speedometer itself periodically and it too can have the same symptoms of sticking intermittently.