Originally Posted by Red Alert

You've said you have an '04. Well all '04s and early '05s have been delivered with the old style differential.

Several folks have had problems with the diff failing and not always under load. You need to understand, that despite the failures, more folks than that have had absolutely no problems at all. None. So it is somewhat the luck of the draw.

I replaced mine with a True-Track because I was unsatisfied with the limited-slip that came with my truck. I've had zero problems it either.

I suggest, that if you do not have the finned aluminum diff cover, that you get one as it contains more diff fluid and the fins and aluminum help cool the diff. Then make sure your diff has the newer spec synthetic diff fluid. This is important as it removes one mode of failure, over heating.\

When you have the cover off, make sure the bolts on the diff are torqued to proper values. Also inspect the spider gears to see if there are any signs of improper wear or signs of over heating.

If you want to do as I did and replace the diff, then make sure you order new bearings and oil seals at the same time so your rear end will be fresh.

Red