If you have the axle shaft removed, use a big C clamp and a deep socket for the threaded part to push into. Tighten the clamp, and then hammer on the jackscrew. Keep tightening and hammering until the spline seats. That will keep the thread from getting stretched.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!