Duster 360 *Snuffy* New exhaust and 8 3/4 !!

Those bearings are pressed on the axle shaft and then retained with that pressed collar, on the other end the retaining plate bolts to the housing and keeps the bearing from coming out. Welding on heat treated material like that axle is not good. It's already been heated to treat it, now that you super heated a small area by welding on it you may induce small crystaline fractures into the metal because now it's been overheated. So you may indeed break an axle when if you had left it alone you wouldn't have.

Just because someone had an 11 sec pro street car that doesn't make them an engineer or a metallurgist.