I think the instructions say to tighten the diff not till its snug, and then back off 1/8 of 1 full turn.
That is what I have used when assembling my T4 or B4 diffs in the past, and that has worked well. After that, I then play with the slipper setting. You need to make sure your diff is set right before working on the slipper.
Also, make sure that you have the diff in the right way in the tranny housing. If its not, it can open up ( the diff setting) on you.
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