I am still having problems with my 4 wheel drive . I replaced fork shoes. what I put the truck in 4 wheel drive the shift fork operate properly . but it will not stay in 4 wheel drive . it stops right back out . on 1 of the axles teeth look chewed up at the end. should I replace the axle and collar

 

Do you have good vacuum at the cad? Sounds like the check valve up by the manifold might be bad.... replacing that wouldn't hurt. Either that, or you have a vacuum leak somewhere.

If the parts like rather chewed up, yeah, time to replace 'em.

 

no doubt, the collar needs to be able to slide over the shaft end to join the two with EASE. if the splines are messed up, that won't happen

 

you might can salvage the axle and collar by filing off any burrs and creating nice clean splines. a new, sharp flat file and some patience can do wonders. it fixed mine. you want the collar to be able to slide on/off with ease.