rear axle leaking

[BBB-Dmax]

I have had it in 2 times for the same problem not under warrenty of course. Had to pay for new brake shoes alos. This time it's just one and found it before it ruins the pads this time. Question is this was fixed both times by the dealer, last time it was past the 12 months so they didnt cover it.I havent brought it in yet but it has been past the 12 months because I just got back from Iraq after 16 months. I'll have to check the milage but i'm guessing it isnt more than 5k or so. I'm wanting them to take care of it so we will see. Reasonable or what? Dont understand why this keeps happening tho?
Dan

[DmaxMaverick]

There are a couple reasons for leaky axle seals.

Obviously, a bad or improperly installed seal can leak. Once you've had it repaired, it should not leak again. Both should not leak within a reasonable time of each other.

Blocked vent tube. If the vent tube is kinked or blocked, it will allow pressure to build in the rear end, blowing lube out a seal, and sometimes both. Replacing a seal under this condition is temporary. Check the vent tube to be sure it is clear, and is in a constant incline to the end, which is near the fuel filler pipe. If it has any dips or loops in it, lube will accumulate in it and block free air flow.

Overfilled. If the level is too high, lube will get slung onto the vent hole, causing case pressure as the diff heats up. The proper level should be about 3/4" BELOW the fill hole.

Lube type. If you use the wrong lube type/grade it can attack the rubber in the seal. Be sure you are using the GM stuff ($$), or a known compatible synthetic lube. I've been using Amsoil 75-90 and 75-140 w/o problems for over 100K, but mine doesn't sit for any period of time.

Check the spindle for defects. If it has been sitting for a long period, pitting can develop on the sealing surface of the spindle. It is bare metal, and long sitting lets it dry out, exposing the metal to the elements. It is possible your axle housing was defective from the manufacturer. If that's the case, GM owes you a new one, regardless of the miles/time you have on it, as long as you have had it repaired once for this under warranty. The housing should have been replaced under warranty the first time. If it is damaged, and GM won't work with you, try a Speedy-Sleeve. This can/will seal it up.

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