1928 Chrysler Speedometer Cleaning

[leomara]

My speedometer was not working, it appears the odometer reset is stuck and the speedometer speed indicator does not spring back.  I opened up the unit and it does not appear to be damaged, the speedometer speed dial spring spins the dial, the unit is just dusty/dirty inside not rusted or damaged.  What kind of a solvent can I use to clean it?  Can it be soaked?  If that does not loosen up what is stuck I will seek professional help. 

[HarryLime]

It is best not to try a solvent bath . Like a fine watch , it should be dis assembled for cleaning and lube .

[DFeeney]

Hello, I believe you will find this a expensive fix, perhaps the grease has hardened , perhaps the die cast  is bad, perhaps a little of both.  Don't be surprised with estimates $400-600. I have had two from that era repaired and they seem to quit again after a few years of summer driving.

[maok]

There is a good chance that the diecast/pot metal has swelled. I replaced my 1928 series 62 (now sold on) with a rebuilt Ford Model A speedo (I cant recall if its '28-29 or 30031 version), the trip meter reset stork is different  but can be modified to work. 

[trini]

Varsol is about the safest cleaner. Use a fine paint brush. Do not soak. Just keep brushing until all the gunk is loosen up. Then rinse with warm water. Soaking will obliterate the numbers. Have you tried Bob's Speedometers ? He advertises in the Hemmings Magazine. May be a little expensive but does a great job.

 

[leomara]

I also have a Model A Ford which has a Waltham speedometer.  The construction of the Waltham appears to be much more serviceable than the 1928 Chrysler.  The Chrysler speedometer after removing the back cover which instead of being held on by screws is held on by crimping edges to the main unit does not look like it was designed to ever be disassembled for cleaning or repair.  

[pmhowe]

20 hours ago, leomara said:

the unit is just dusty/dirty inside not rusted or damaged.

and, since you didn't mention it, probably doesn't have any hardened grease. If that is the case, I would try cleaning it with CRC electronics cleaner or throttle body cleaner(or a similar brand). They come in pressurized cans so you might not to have to disassemble the part.