Well I guess I should have also said I replaced the clutches with the spiders. I did dump oil on them when installed.

another option is the ARB air locker, its a limited slip in normal conditions, flip the switch and it locks fully. and yes, they do make one for the dana 80. its pricey but worth it. Local buddy has 5 years of sled pulling on his and is making over 800 hp, no problems to date with the ARB

did you use the limited slip additive? seems odd to me that it has broke the same thing twice i still think something else is goin on there