Outer Limits 4x4 Board

GUDDAY ALL!!!
just brought a 60's cruiser off a mate, now he has had it for a while and it has had issues with the rear pinion seal and bearing's it keeps chewing out seal's and bearing's
it has had approx 4" lift - 2" inch heavy duty load carrying springs, 2 inch snake racing extended shackles, the lift appears to have brought the rear diff forward as the shackles now sit vertical no angle at all and the tail shaft seem's to be to long - my guess is the tail shaft needs to be shortened and diff wedges????????

what do poeple think any opinions would be great

hi, ive had some exprience rebuilding diffs and observed the work others do too. if a differential and pinion preloads are set correctly and proper tooth mesh is attained, there should be no worries with it. however problems can arrise from the tail shaft and angle of rotation of the axle - such as the angle the universal joints are set to. universal joints display a "fast-slow" characteristic, which, if they dont cancel eachother out on oposing ends of the drive shaft can lead to vibration, and hence increased wear. it is possible that this vibration (which can be felt at high speed) could be rendering the seal useless (by way of flexing) and allowing dirt to enter and damage the bearings. -this can be simply fixed by correcting the angle of the axle. shaft length is an unlikely cause because the higher you lift the longer the shaft will need to be - right? in the case of the axle being brought forward, we need to ask why? is it because of larger tyres? - i dont know, but there are three main reasons why this may have occured:
1. the uni-joints are not concentric.
2. workmanship to the differential and pinion are not up to factory standard.
3. off road damage-where the tailshaft has taken weight and damaged the seal.

i have seen these thing happen to other people, as well as myself. other than that someone else may have another opinion. !!! dont shorten drive shaft unless you need to !!!

Recently did this to my 60, 3" suspension lift, with 2" ext shackles.
I also found that it had brought my rear diff forward.... about 1-2"
Only running 275/70/16's - no vibration at high speed.

Had to get a custom rear tailshaft made as trial fitted 3 (original + 2 spares) and they were all too long.

As for wedges... did not have to get them as the new tailshaft fit perfect..
Tailshaft cost me about $300 - $400

thanks for the reply guy's!!!

I had a 60 a few years back and same thing once lifted (springs and shakles) it brought the diff forward and the same result back then- the tail shaft was to long, i ended up fitting a fj55 shaft as they are approx 1" shorter so will prob try that 1st and also fit wedges to bring the angle on the uni's back, just wanted a few other opinoins
thanks again!!!

what is the sealing surface on the pinion flane like? if its rouch and rusted it might be chewing out the seal.. they are only about $40 new and solved my issues.

thanks for all the info
found the problem -- the pinion shaft itself was worn -- new shaft new bearings and seal all fixed-- $350 later --