RR Axle seal leaking (Again)

FL335i · May 2, 2016

This weekend I installed my PML diff cover. While laying on my back getting ready to start the job I notice the right axle seal is starting to leak again!! Dammit. When the truck was only about 9 months old and had 16k on it the RR axle seal let go pretty good. oil all over the wheel and tire. Dealer repaired it and I cleaned everything up. It's been bone dry since until now. Truck has 43,500 miles on it. Noticed it's starting to get wet and it's definitely oil. What a bummer. But more importantly, what's going on here. Two axle seals on the same wheel in 43k miles. Never had issues with axle seals like this before in my life.

This is oil leak # 3 in 43k miles.... 2x on the axle seal and 1x on the flywheel bolts.

Edited May 2, 2016 by FL335i

Silver ice 6.2 · May 2, 2016

Do you have offset wheels? Buddies of mine have lifted trucks with tires sticking out and have this same problem..

FL335i · May 2, 2016

Stock 18" wheels. Stock SRA goodyears man. No lift, no level. Nothing. I still plan on keeping the factory SRA's up to around 60k at my current rate. My truck is empty 99% of the time.

Edited May 2, 2016 by FL335i

O_J_Simpson · May 2, 2016

Oil leaks happen. Just warranty it and move on.

Jon A · May 2, 2016

It makes me wonder if that axle shaft has a machining flaw or if the bearings were installed incorrectly somehow. There's no good reason you should blow that same seal twice in this many miles.

How do you like that PML cover? They look nice.

tnchevy · May 2, 2016

Either the shaft has a flaw or the mechanic who replaced it did not get the new seal seated properly.

FL335i · May 2, 2016

^Something is going on. This time around I want to see it taken apart prior to them assembling. The PML cover is nice. I added a Gold Plug drain plug to it. Their magnetic drain plug is a bit weak. Aside from that love it so far. I'm pretty ticked that the PML cover will have to come off and I'm going to loose all that new synthetic gear oil. I'm running 75/90 Triton FE GL5 oil from Conoco Phillips. Has Eaton approvals and everything. NO LSD additives for the G80. I think when the dealer repaired the leak the 1st time at 16k, they put the wrong oil back in it. It was for sure not the GM stuff. Just looked like regular 80/90 jobber oil.

Side note. I did my front diff also this weekend. Front diff was never changed. So it had the full 43,5k. It needed it. Bad. I use 4WD and Auto 4WD quite a bit. The oil was black and the magnet was covered in the normal break-in debris. I cleaned everything up and put the 75/90 GL5 Syn Triton FE oil in it.

Edited May 2, 2016 by FL335i

Shu · May 3, 2016

Those seals and wear out quickly if they failed to apply some grase he seal lip. A bent axle, An axle with a burr rough section and improper installation could all cause a bad seal.

FL335i · May 3, 2016

^yup. makes me want to try this next one on my own.

Shu · May 3, 2016

The seal and gear oil are inexpensive and if you have the know how, then go for it IF it is out of warranty. If in warranty, I'd get them to change it again and document this is the second repair so they check carefully for the things above.

FL335i · May 4, 2016

Still in warranty. 20 months, 43.5k. Should fall under the power-train warranty. I cleaned the area up tonight. I drive a ton, I'll give it a week or two and see how it's looking. I want to know I cleaned it, and it came back.

FL335i · May 8, 2016

Since I've decreased it very well and confirmed I started with a bone dry clean area, nothing has come back. I've driven about 150-200 miles. Nothing. I'll keep an eye on it and see if it comes back. With how small the leak appeared to be, I'm betting it will take 500-1k to show back up if it is indeed leaking. I will be taking the rotor off and doing an inspection back in there to veryify There's no oil in the e-brake shoe area.

FL335i · May 12, 2016

Well I checked it tonight. Without a doubt leaking again. I've run about 3 tanks of gas through it since I de-greased it well and confirmed it was bone dry and clean. It is leaking again. darn it. Off the dealership I go.

BuyAmericanIron · May 13, 2016

I agree with Jon A and Shu. One thing not mentioned is the vent tube and cap. Have the dealer make sure the vent tube is freely venting and the cap is in place and not restricted. If the vent is blocked, it will cause excess pressure to build when the differential heats up and the oil will vent from the weakest point which will most likely be an axle seal. I would lean towards a defect in the axle that is causing premature wear in the seal. Good luck with your repair.

FL335i · May 14, 2016

BuyAmericanIron- When I did my PML cover the other week, I traced the vent tube up to the gas pipe. With the diff cover off, I blew into the vent hose and it was free. No restriction. I thought of this too... Not the issue. I'm guessing it's a bad axle shaft machined surface and the dealer techs are in too much of a hurry. This 2nd time I will demand to personally inspect the housing, seal, shaft etc prior to assembly. now I'm out a bunch of new 75/90 Syn Gear oil. FML.

Edited May 14, 2016 by FL335i