Stovebolt.com Forums The Shop Area Driveline Jittery Speedometer Needle

My speedometer and odometer both work perfectly in that speed and distance are accurately recorded.

The odd thing is that the needle is jittery and bounces in a 5mph or so range when first starting out. It's most noticeable at 50-55. After a few minutes of driving it smooths out and stays perfectly still at whatever speed you're traveling.

The only thing I can think of is that the drive gear in the transmission needs to get warmed up with hot oil before it turns smoothly. Is it some other cause?

Is this something I need to deal with or should I leave well enough alone and get busy fixing the horn?

The speedometer cable is new. The gauge and tranny are original.

Mine turned out to be inside the speedometer. I had to disassemble and remove all the rock solid grease from 70 years ago. Disassembled, cleaned, and lubricated the gears. My needle hasn’t bounced since.

Did yours bounce all the time? Mine only does it for the first 3 or 4 minutes of driving after a cold start up in the morning. After that it's steady as a rock for the rest of the day.

I agree with the thought of the speedo head needing attention. Mine was very noisy and erratic when cold, disassembled it, cleaned and very light lube on the input bushing, now it's quiet and smooth.

I guess I'll have to deal with that when I get under there to install new instrument panel bulbs.

Somewhere here I've shown how to remove the plug (or plugs) and lubricate the speedometer head...also have provided free image files (speedometer, gauge faces and odometer) for use with waterslide decal paper (use the white decal paper as your printer can not print in white). I want to say I even posted the reverse image for the odometer (black background with white numerals). It is all here somewhere. Good luck! I think the jittery needle problem is in the speedometer head in your case. Use a thin oil...you can use WD-40 if you spray a bit into a small jar and let it separate. The top layer will be a fine light oil and the bottom layer will be paraffin, immiscible solvents and other junk you don't need.

Thanks.

Mine bounced erratically. Sometimes a lot, others not a lot. It also made a terrible scratching sound. Slight, but awful. I think yours stops because of the truck/cab heating up? Perhaps the grease softens up a tad? Georgia is a lot warmer than up here! 😉 I’d still tear it open and clean it. I bet it stops. Good luck!

Thanks. Today is only 37degrees this morning so I'll be able to see if it's related to the temperature.

28* here this morning and the Speedo needle on our ‘62 C-10 started jumping around. After getting some heat into the cable, by driving, it settled down. It’s time for some speedo cable lube.