Anyone know the actual p/n for 8" rear differential gasket?

[Capote]

Seems like a mystery as to what is the correct part number when it comes to people ordering them from what I've been sifting through on old threads. I don't have leaks or anything, but I kind of wanna pop open the rear diff and have a look inside to see how much fluid drains out. This rear axle was taken off of a Rainier (a neglected one) that spent it's life in Ohio after all. It's all dingy and i'm wanting to paint the whole rear axle flat black.

 

[Mooseman]

Shouldn't be that difficult to find but honestly, I usually just use RTV. If you have the original gasket on there, it's a rubber/metal type. I was able to reuse mine on the replacement 2008 diff for my Saab. I did look up for the same type replacement and found it too expensive for what it is (I'm cheap).

 

[littleblazer]

I went to the dealer, was about 40. Let me see if I can find the p/n.

 

[mrrsm]

These guys have a cool visual chart at the bottom of their Main Page and sub-listings for GM, etc. by RPO codes:

http://www.differentials.com/technical-help/differential-identification

 

[littleblazer]

The one I ended up with was 12479020.

 

[AWD V8]

In my 45 years of vehicle servicing, 9 years in fleet service, I have never used a diff cover gasket. I've done literally done thousands of diff fluid changes and never had one leak.

I use the best RTV out there, Permatex Right Stuff

I use it everywhere. Never had an intake or water pump leak, or any place I've used it. Just make sure the cover and housing are clean and dry. Install within a few minutes and if you are using synthetic oil, let it set for about 20 minutes after getting the cover on before you fill the diff.

 

[Capote]

These guys have a cool visual chart at the bottom of their Main Page and sub-listings for GM, etc. by RPO codes:

http://www.differentials.com/technical-help/differential-identification

I've had that site bookmarked for a while lol

In my 45 years of vehicle servicing, 9 years in fleet service, I have never used a diff cover gasket. I've done literally done thousands of diff fluid changes and never had one leak.

I use the best RTV out there, Permatex Right Stuff

I use it everywhere. Never had an intake or water pump leak, or any place I've used it. Just make sure the cover and housing are clean and dry. Install within a few minutes and if you are using synthetic oil, let it set for about 20 minutes after getting the cover on before you fill the diff.

I don't mind using RTV, used it on my TB and Cutlass before in various applications. If I can't find a cheap gasket or my current one doesn't look reusable after removing it, i'll look into the Permatex Right Stuff.

 

[littleblazer]

As long as it wasn't driven in salty conditions, the oem gasket will be fine. Mine the inner metal rusted out. It wasn't leaking but I didn't trust myself to reuse it.

 

[HARDTRAILZ]

I never use gaskets on diffs. My buddy swears by some Lube Locker BS gasket, but I think it is just cause he got upsold on them when he did his lockers and now does not want to admit that.

 

[C-ya]

RTV here as well when the one for mine didn't fit. GM part number crossover for the 8.6" - not so much. Holes didn't line up.