sometime what happens is the case breaks near the bearing support, this is due usually to a large rock coming under the case and forcing the case upwards as it passes, also it can happen on extreme hard side landing were you force the dogbones into the side of the case and it cracks the plastic.

what happens next is as you apply force to the dif the case moves allowign the spyder gears some play, as soon as one gets enough play the force is only on one tooth and the gear snaps, one breaks then it multiplys and soon you have four very exspensive broken gears.

best method to avoid.. if you hear a weird click, and you can not find a exterior gear with a chip, stop and take the diff apart( you may only need one gear at this point) .

best prevention, alloy case upgrade, adjustable is nice, and our preferance is to cut the chassis to keep dogbones as level as possible without lowering the ride ht.

The alloy conversion is pretty reasonable, check with a dealer for acurate pricing.

in our onroaders the plastic diff will last forever, as it is the rocks that cause the stress, in the offroaders depending on were you run we have seen easily a years worth of hard running out of a stock diff and case, some of that is just luck as to what the enviroment is you run in.

And remember you may not know when you strees the case the gears will not slip then they will usually fail in a high traction condition after the case is cracked or broken. Also the cover and its dents have no influence on the insides of the diff, the plastic carrier is what controls the gears and there position.