Speedometer Troubleshooting question

[Dave in Boise]

Hi All,

Over this summer, both of my cars have had their speedometers stop working

1) The coupe stopped after I had to pull out the dash and replace the ammeter.. Can the cable pull short out of the speedo end, or did flexing it perhaps cause the inner cable to snap?

2) The Tudor just stopped working.. no external factors I can see.

Big questions.. How best to test the system to locate the trouble? Take the bottom off and spin it with a drill from under the car to eliminate the sending gear, or pull the cable from behind the speedo and see if it spins while the car moves forwards, or?

Not sure where to start, as I cannot swap 1 component out for a known good one as both systems are suspect. Need some advice please

- Dave

[CarlG]

I made a short cable out of a piece of scrap cable that I plug into the back of the speedometer to test with an variable speed electric drill. You need to run your drill in reverse though.

[pooch]

Drop the cable off the back of speedo and drive and grab turning cable with fingers lightly to see if it is smooth and transmitting torque.

This will eliminate from the speedo down.

To drive the speedo, I did not have a piece of cable so I used a small tap with the correct size square head in a drill.

[papanick]

if you need them rebuild let me know. jr.

[Mark in MT]

Another thing to look out for is the driving end on the oval style speedometers. The square end should be .125", the rest of the world including the round style used a .104 square end. The smaller end will work for a while, then the corners of the end will round off and slip inside the drive end of the speedometer.

On both styles, the square hole in the drive end is recessed in about 1/8" or so before it becomes a square, you have to make sure that the cable is sticking out far enough from the housing to fully engage the speedo head.

[H. L. Chauvin]

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Hi Dave,

If you or anyone one else may be concerned about "not" having a speedometer for several weeks or so while it is being repaired, the gentleman in above Reply No. 4 takes pride in giving customers immediate attention with quality work.

As mentioned previously on this Forum by others, this is his typical type of Model A speedometer service:

1. One mails him a speedometer on a Monday with the new USPS attention given to "insured U.S. Post Office Priority Mail", with a tracking number -- maybe $11.00 depending on one's distance from NY.

2. He gets it on the following Wednesday of the same week.

3. He repairs it on Wednesday, lubricates it, paints the case black with lacquer or a very fast drying paint, cleans & polishes the chrome & glass, applies new numbered decals, sets odometer to zero or whatever one wants, & usually places it back in insured "Priority Mail" that same Wednesday.

4. It arrives repaired on Friday -- maybe as late as Saturday depending on mailing distance & special repairs; but for me on two (2) occasions, it arrived on Friday of the same week after he told me he was not extremely busy these particular weeks -- really not many Model A owners needing speedometer repairs in the U.S.

If I had to guess, it appears that this gentleman finds repairing & restoring speedometers about as difficult a task as a young slim man finds in properly tying the shoe laces on his shoes.

Just thought I'd share a couple of good experiences with a nice Model A service.

[CarlG]

I can also attest to the service that JR gives. He usually has "exchange" units available that he can ship same day. He does beautiful work!