The Stovebolt Site Forums The Shop Area General Truck Talk Speedometer Rattle and Jumping when Cold

I've noticed the last few times driving my 52 pickup that the speedometer makes a rattling, grinding noise when it's cold. The speedometer will jump up to 70 and drop back down to where it should be. This seems to go away after the truck warms up some and I rarely (if ever) hear it or experience this when the temp is warm outside. I read somewhere that you need to lubricate the cable or something but it wasn't very clear. Do any of you fellow bolters out there have any experience with this or advice? Thanks in advance (pun intended).

The cable can be pulled out of the housing(jacket) and cleaned and oiled. I had a terrible squeal from my speedo when cold, it wasn't the cable causing the noise, it was the bushing in the speedo where the cable nut threads on.

Interesting... Thank you. Did you have to replace the bushing?

Pull the cable out out of its sleeve and lubricate it. I used white lithium grease when that happened to my old speedo. It, too did what you describe when it was cold.

The grease stopped it but about a year or so later, the speedo itself fell apart and I installed a rebuilt one. If lubricating it doesn't help, leave it disconnected until you fix the head itself.

Your cable might need to be replaced altogether if it's broken or rusty or something.

I didn't have to replace anything, pulled the gauge cluster, disassembled the gauge cluster to get the speedo out, gentile clean with gun scrubber or similar, very light lubrication on the bushing with gun oil or clock oil. Been good for a couple of years now.

The problem isn't the moving cable- - - -it's the flex housing it runs in. The spiral wires that guide the spinning cable get rough spots that cause the cable to bind, wind up, and unwind, changing the rotational speed. Once things warm up a little, the problem diminishes, but it never really goes away. The only good fix is to change both the cable, and the external housing. Lubing the cable is a temporary fix at best.
Jerry

I greased the cable and that seemed to help a little but what really did the trick was pulling the gauge out. On the back of the gauge where the cable connects is a little hole with a brass cap and felt piece inside. I cleaned that out with parts cleaner letting it run back out toward the cable attachment hole. The I put a few drops of gun oil in there, saturated the felt piece with oil too. Smooth as can be now.

Glad that you were able to get it to run smoothly, you will probably notice a steadier needle while driving.

How did you get that little brass cap out .curious as I may try this sometime down the road

I used a small flat head screwdriver and applied pressure to the outside wall of the cap. I worked it a few times and was able to gently pry it up and out. Then used a sewing needle to get the felt piece out.

Thanks good to know .👍