I have a number of original Ford rear axle shafts that are good except for the keyways being worn. Would cutting a new keyway weaken the shaft? Has any one had any bad results doing this?
At Chickasha the year before last there was a rebuilt Ruckstell axle for sale. It had new keyways recut in both axles. In my view it would work OK, but if I could afford it, I would just buy new axle shafts. It will weaken the shaft somewhat just as cutting the first keyway did. The question is how much is somewhat.
I don't like to begin a repair on a weakened foundation.
Randy, one way would be to mill the keyseat to the next larger size and then mill a step key. That is a key with steps that will fit the standard keyway in the hub and the larger keyseat on the axle. This will weaken the axle less than cutting a whole new key seat and will work quite well. I've used this method many times on other applications. Hope this helps. Bob
If you're going to cut new key ways; make sure you do it 180 degrees from the original to reduce shaft weakening to a minimum. I did this on a 1913 wide track touring back in the 70's and to my knowledge, It hasn't caused its owner any problems.
I like Roberts idea. Also, an otherwise good hub could be salvaged this way. I have had step keys made for many applications over the years. If you think you may need more than one, they can be made much longer and then just cut off whatever is needed, much cheaper and handier that way. Dave
MMC sells step key stock in 12” lengths.
http://www.mcmaster.com/#step-keys/=havpq5
One problem is usually the axle taper is worn so the hub fits on too far and the brake shoes rub on the sides of the brake drum. Sure you can use the shims. I make my own axles and usually make then just a bit longer if needed to fit the hubs I am going to use and locate the hub where it is supposed to be.
Randy,
It's not a good idea. There just isn't enough material left to be safe. Think of how little cross sectional area would be left just behind the threaded end. I have widened a keyway on a non-Ford, where getting a new axle would be difficult, but I wouldn't bother for a Model T. I would get a new or good used axle.