As mentioned previously I damaged the threads of the off side stub axle extracting it from the suspension upright, this is how I repaired it. To do this, you need at your disposal a vernier caliper, the Japanese digital ones by Mitutoyo are the best available, you will also need a thread chaser, a die wrench, a a good quality carbide cutting tool, and a decent Lathe. The Lathe I repaired this on is an old 1970's Colchester Triumph 2000, a fantastic well built lathe.
I started by locking the stub axle into the three jaw, and making sure its centred, you can clock it if you think it’s totally necessary, but I know this three jaw chuck is pretty centre so I didn’t bother.
I then proceeded to cut a small taper into the end of the stub axle using the cross slide with a carbide cutting tool cutting no more than 5 thou deep, just to take the threads of the damaged end, turning at around 425 with plenty of water soluble suds.
I then ran a thread chaser, 24 TPI UNF through the remaining threads just to increase the definition of the remaining threads on the end of the axle to help with the next step.
Pinning a die wrench with a ½ 24 TPI UNF die between the tailstock the and job with the wrench handle jammed against the bed, I slowly proceeded to turn the tail stock leaver and the headstock simultaneously by slowly by hand keeping the die straight until it bites onto the first thread and begins to cut. This ensures an clean straight cut thread perfectly incline with the old one.
It worked and a cleaned the thread up and threaded a new nut on just to make sure it was nice and tight, Good as new! Danaged stub axle repaired.
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