Hello all. I've decided to change the fluid in my front and rear differentials at ONLY 7300kms. I was hearing a 'popping' sensation from the rear end when the diff. was hot coming off the highway. Dealership says the fluid needs to be changed so soon due to a 'break in period for the clutch pack.' Well news to me! Is this true?? Anyways, bought the fluid but do I need a gasket or can I just use some good RTV silicone?? I've used just RTV on my Dakota without any problems. Thanks to all who reply!

 

WOW!!! Only 7300kms... That should NOT be necessary.

Anyway, a gasket is available if you choose, but RTV will work as well.

 

Thanks for the reply Mr. Admin. Anyways, I was flipping through the maintenance schedule of my owners manual and believe it or not, at 5,000km it does say '**see footnote' so I did, and it said Diff. service and a GM tech did say the same thing. Ah well $33 for synthetic fluid and I already had the RTV.

 

Hmm... Never did see that, but then again, I never had my Bravada when new.

So with the service, I created a post a while back with pictures and such on how to do a proper rear end service. But it was mostly for a 50-75k mile service, not a as new service. I used some brake parts cleaner to wash all of the old lube out, then used a new gasket and filled it up with some Mobil1 75w90 GL5 rated diff lube. If you have a limited slip rear diff (RPO code G80), then you'll need to have the GL5 rated lube to protect the clutch packs.

Here ya go: Rear Diff Service

 

im looking to do the rear diff in the spring. i bought the truck with 145K on it and i don't know if the rear fluid was changed at all. i know im the second owner of the truck and i know the oil was changed and the trans fluid was changed regularly. i have the limited slip rear so i do have to run a certain fluid? i wanna get it right cause i don't need to replace a rear end on my truck.

 

I wouldn't use RTV on the rear-end. While it may work fine, I think a Fel-Pro gasket is the best way to go. +1 on the brake cleaner. Works great for removing old clutch material and getting it cleaned up well.

 

Never heard of changing diff fluid so soon. I didn't do mine till 95K. Probably waited a bit too long, but it still looked ok. I went with the gasket option and cleaned everything up with brake cleaner.

 

At 80k miles, I will be changing my rear diff fluid. Found some good how-to threads on this. I just want to make sure I have the correct stuff for the job. Can someone help me with the correct fluid (type and how much it needs), a part number for the gasket and which type of gasket sealant? I have a 2000 2dr 4x4.

 

GM Part number is 26016661 for the 7-5/8" rear and comes 2 to a pack. The gasket can be purchased in the aftermarket as well. RTV can also be used (sparingly) if you do not want to go with the gasket (gasket is easier IMO). The rest of the information you require can be found in this thread and the thread linked to in my last reply in this thread.

Post up here if you have further questions.

 

To answer your other questions, I've been running Royal Purple 75w90 synthetic gear oil and used RTV black for the gasket, and have had no leaks, no problems what-so-ever for ~3000 miles. If I were doing it again, I would just buy the new diff cover from the dealer, and a new gasket set instead of cleaning the old cover and using RTV. That was the hardest part of the job[:'(]