cleaning/lube bouncing speedometer


Knuckle Buster
Feb 21, 2010
Willys Model
Willys Year:
my '48 Wagon speedometer needle bounces badly (not the cable, I've removed, cleaned and greased it. it's fine). I was wondering if anybody new how and if possible to disassemble instrument box to clean, oil, grease, etc the internal speedometer gears. (?)
It didn't appear at first glance to have a back plate specifically behind the center speedometer to remove. And I'm a little nervous just digging into to something with teeny parts without checking around first.
I cannot speak to the Willy's speedo, but my guess is most of the older stuff is all the same just with a different logo/face on it. I have worked to fix these before on various old rigs and step 1 you said you have done. ClEAN and grease the cable. If that does not do it then its either in gears at the speedo and or at the driven point.

1) Inspect the end of the cable to insure its not so rounded as to allow slippage

2) Inspect the insert point (most often on the trans) to insure that it is not rounded out, worn gear and especially make sure the screw on attachment sits fully on and is tight.

[I have always done the above first and more often than not this has solved or at least improved the problem]

3) Speedo: Here again WD 40 in a spray can is your friend. Since its mechanical you can attack it liberally with the WD to clean it (you might want to pick up a can of compressed air for cleaning the inside of computers). If any of the gears inside are plastic be very careful as they will break very easily. If they are metal its usually weak pot-metal castings and can be worn or have a broken tooth. Generally if a good cleaning does not fix it at the speedo then I see it as above my pay level leave it alone. I have never had one that was not better after cleaning and some light lubing.

Let us know how this progresses and how you improve or solve the problem... ;)