Diff bearing failure after rebuild?

[ProjectZS]

About 4K my RS turbo had to have the box out as the selector mechanism had failed. The box was stripped and had all bearings replaced, after rebuild I noticed the box whined a bit but thought it was maybe due to these Uprated bearings and I’ve heard the LSD’s can be quite noisy. Last week or so though I’ve noticed a leak has sprung from the n/s driveshaft oil seal, popped the shaft out to swap it over and it still leaks. Whilst the shaft was out I noticed quite bit of play in the diff bearing on the n/s that could be felt quite a bit when rocking the shaft, the o/s one is pretty solid. Anyone able to advise on why this may have happened so prematurely? I rebuilt the box myself, used the correct oil etc. Seems strange why only one side has gone, do have a video of the play if it’s possible to upload.

[996TT02]

Shims? Clearance? Preload? Replacement bearings are rarely identically sized, over-tightening causes premature failure.

Rather than buy a bucket of shims to try out (every time destroying the very £££ bearing to remove and replace shim) my box rebuilder calculated the clearance needed and had, if I recall correctly, 0.3mm ground off the bearing itself. It's the difference between a bearing that is seizing and one that is properly clearanced.

That's just my theory about what happened with yours of course, hard to prophesize what really did happen.