XXX-CR Diff-iculty!

[philly]

I'm having a bit of bother with the diff on my xxx-cr, in that it's slipping way too much, or not at all! If I go by the adjustment suggested in the manual, it's so loose it slips under normal acceleration. If I tighten it right down and then back it off I find I have only about 1/2 to 3/4 of a turn before its sloppy. Is this right. The car is fairly new, probably about 8 club meetings so wear shouldn't be an issue. I guess I'm just not sure how much 'give' the diff should have...