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Classic/Antique Car Repair/1931 speedometer problem


how can a person trouble shoot a speedometer installed in the car that does not work. The 1931 Model A runs fine. The installed speedometer looks good(don't know if ever worked)cable assembly is installed and attached to the transmission. Any suggestions to determine a problem before removing complete assembly?

What usually happens is that the main bearing in the head of the speedo tightens up and is very hard to turn, and it breaks the cable.  It is rather hard to fix this problem.  Let's hope you don't have that problem.  Jack up one wheel, Put it on a jack stand, don't trust the jack, block the car from moving, make sure the wheel is free to turn, be very careful, and start the engine and put it in third and let the clutch out.  The jacked wheel will turn, and while it is turning, observe the speedo cable.  It should be turning.  If not, something is wrong at the trans, or the cable is broken.  Now take the speedo head and try to turn the center shaft with your fingers.  It should turn easily.  If not, the bearing has tightened up and broken your cable.  
This should let you determine where the problem is, and if you do have to fix the bearing, I can help you with that.  Good luck.  jack

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jack bahm


Only repair type questions on the 1928-1931 Ford Model A.


Owned one when I was 15 yrs old, and now have owned 5. Still own and play with 2 of them.

Oakleaf region of MARC. Model A Restorers Club. I have put several Model A videos on the Oakleaf site that may be of help. Things like how to start the A, how to Time it, how to troubleshoot it.. Go to and you will find them. Also, go to and search for "jackbahm" and you will find over a hundred videos. Many about the Model A and our outings. jack

"More than you need to know about cars." Just a small book for Car Nuts. "Model A Ford Tips and Hints" "Get A Horse" (What to do when Henry's Lady quits on you.) or Snyder's Antique Parts. "Engineering Stuff" (For the Kid who likes to take things apart and get them back together). Kids book for ages 10-16. 2012 Many Model A movies that can be found on

BSME LSU, 1958, Masters of automotive engineering from the Chrysler Institute of engineering, 1960, MBA Mich State, 1976. Worked as an engineer at Chrysler from 1958 to the end of 1991.

Awards and Honors
Two patents while working in auto industry. Go to this site for my Model A videos.

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