1931 Ford Model A Roadster

1931 Ford Model A Roadster

Wednesday, March 12, 2014

Front Axle Repair

As soon as I finished adding the new leaf to the front spring, I was ready to assemble the front suspension to the frame.  I got the front axle and cleaned the holes for the spring perches and king pins and was just about to start assembly when I noticed the front axle looked like it had an unusual curve to it.  So I did some checking and  discovered that the four holes that should be in line with each other were out by 3/4 of an inch.  Both ends of the axle were bent back at the spring perch holes and the center had been pulled forward as well.  I also discovered that it had a 1/2 inch twist in it and the left side kingpin boss that should have had a 7 degree angle was almost straight.  I called all the local alignment shops to ask about straightening an axle and quickly discovered they don't do that anymore and if it was going to get straightened I was going to have to do it.  So I did some research and discovered that some simple jigs and rods were all you needed if you have a large press.  So I made the jigs and headed to David's transport shop to use his press.  I cut the tops off the old king pins in my lathe and used them as a base for the indicator rods as they would fit the holes perfectly.  Mike came over to help and in under an hour we had it as straight as it came from the factory.  The axle is a special steel that Ford called the AA alloy and it is very flexible.  You had to press the axle past the centerline to get it straight as it springs back a lot when you let off the press.  This was a fun learning experience and I'm sure the car will handle like it should now.  Thanks again to David and Mike.  More pics when it goes back together!  SS


Front axle set up.

Front axle straightness check.

Front axle 7 degree angle.

Front axle and alignment rods.

Front axle centerline.


Front axle in press.



I just found these old Ford pics from 1931 showing the strength of the A model axle!


Ford axle twists.




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