Axle/Auburn Diff Problem

[hiflyer727]

Hey guys, here is the situation: Helping a friend restore a 1963 Plymouth Fury. It has the 741 case, and tapered axles, as you may know. He purchased an Auburn Posi Differential for the 741 case. A friend installed the Auburn without an issue. But, here is the problem. We installed the one axle and all went fine.....However, the other axle will not go into the Auburn unit the whole way. The axle extends past the axle tub by 3/8" !! It will not "seat" the whole way like the opposite axle did. We checked for any obvious obstruction, can not see anything. No burrs on the axle end, or in the posi unit. Why will the axle not go completely in? Any help would be greatly appreciated.

 

[Dako]

Is it making a 'hard' sound or 'soft' sound when it stops going in? In other words is there a 'metal' bottoming out sound/ feel or a soft 'thud' like maybe you are having problems with the seal (outer) end of the axle?

 

[hiflyer727]

Metal to metal sound.

- - - Updated - - -

Actually, we removed the seal to see if that was keeping the axle from going all the way in....still no luck

 

[threewood]

Are you using the supplied axle spacer (looks like a steel marshmellow)?

If it is the same setup as the Tru Trac, the spacer may need to be milled down. If you have the original rear end, measure the stock spacer and compare with the new one. I went through the same thing with my 62 Belvedere, 741 with stock axles. Mine was way too long, milled it down and set the exact spacing with the shims used under the backing plates.

- - - Updated - - -

Are you using the supplied axle spacer (looks like a steel marshmellow)?

If it is the same setup as the Tru Trac, the spacer may need to be milled down. If you have the original rear end, measure the stock spacer and compare with the new one. I went through the same thing with my 62 Belvedere, 741 with stock axles. Mine was way too long, milled it down and set the exact spacing with the shims used under the backing plates.

 

[hiflyer727]

I will ask the guy who installed the posi unit, and new ring&pinion about the spacer. Thank you. I will keep you informed.

 

[Mick70RR]

Sounds to me like the splines in the side gear are not aligned with the splines in the sure grip. Push the half shaft in as far as you can and then rotate it, keeping the other half shaft stationary, and it should drop in.