RXN

My speedometer has always clicked, and the needle would bounce back and forth. This was more so at slow speeds, once over 60 it would smooth out and hold steady.

I replace the cable thinking it was the cable end. nope that did not fix it. Spraying liquid graphite at the speedo head would give the speedo about an hour or two of smooth operation before it would start clicking and bouncing again.

Yesterday, she clicked her last click and died. and when the needle quit so did the odometer. I rely on my odometer for when to fuel up again, as the gas gauge doesn't work.

I pulled the cluster out of the dash last night. I found the shaft that the cable turns to be seized, this drives both the speedometer needle and the odometer gears.

I freed it up. cleaned the bore (no bearing) and greased the shaft. it spins good now.

With just the speedometer parts. (odometer and gears removed) i can get the needle to work about 70% of the time, when i think I've finally got it and I attache the odometer and put the gear back in, the speedometer needle does not move, but the odometer works fine.

Any ideas? How does that shaft rotor spin that (brass/bronze) housing for the speedometer?



thanks

oldspackrat

What year & kind of car do you have?

RXN

it is a 1958 Dynamic 88.

RXN

I pulled the speedometer/Odometer out of my parts car. of course the numbers are faded. so ended up swapping the odometers. then added the missing milage. I went 98miles since it quit. Thank god for google maps. so I was able to put the reading back to where it should be.

I'm going to have to send the old one out for repair.

Octania

Either it works 100% of the time or it is not working....

Not real familiar with 1950's speedos but in the ones I have dismantled, the cable spins a magnet which is coupled to the driven part by magnetic action. Even though the driven member is nonferrous. Same principle on which AC motors work. Same thing if you drop a magnet into a Cu or AL pipe.

oldspackrat

I've done this trick for many friends. Eddy currents & magnetism in general is crazy magic stuff.

RXN

I gave up and took the one out of the parts car.

will have to send the old one for a rebuild.

rustyroger

I made a good speedometer out of two old units for a '59 Cadillac a few years ago. I painstakingly took them apart and built one up with the best or still working parts and it was fine.
A very fiddly job, around the same time I found I needed glasses for reading!.

Roger.