Recommended Fluids - Transfer Case, Front Diff, Rear Diff

[Meccanoble]

This site has blessed me with the knowledge to change all the fluids in my truck when i first got it. I wanted to see if the recommended fluids changed along with how much. I tried searching but I only seem to find discussions of issues/replacements rather than maintenance so far. I believe I have the G80 Rear Diff

VIN # 1GNSKBE03BR362322

I believe Transfer case takes Auto Tranny fluid (synthetic)
Front/Rear Diff takes 75w-90?

Thanks in advance

 

[Foggy]

You got it... Transfer case Dex VI spec...
Front and rear diffs: 75-90 synthetic gear lube
Get Er Done

 

[Meccanoble]

You got it... Transfer case Dex VI spec...
Front and rear diffs: 75-90 synthetic gear lube
Get Er Done

THanks. Any brands you recommend and how much? My understanding is most Dex VI were created equal so dont matter there but that gear oil....

 

[OR VietVet]

If your RPO sticker, on the inside of the glove box cover, says G80, then it is a G80. If you have an owners manual, that is where I like to get all the fluid specs at. I like to use Genuine GM fluids at all times.

 

[Foggy]

You will be fine with whatever brand is easiest for you to find...
I like the valvoline, etc ... But as long as it's synthetic GL-5 you will be just fine

 

[Bob2C]

I used AMSOIL severe gear 75w-90 for the diffs and ATF Signature for the transfer case. Should last an easy 100k.

 

[Meccanoble]

I used AMSOIL severe gear 75w-90 for the diffs and ATF Signature for the transfer case. Should last an easy 100k.

I think the DIFFS can go 100k miles but i hear the transfer case has to be changed every 30-50k miles?

 

[Meccanoble]

Going with Felpro gasket and permatex black gasket maker combo. Confirmed 10 bolt diff. Using 3 qts of valvoline 75w 90 for rear diff, 2 quarts for front diff, 2 quarts of tranny fluid for transfer case. Blue loctite for rear diff bolts and white loctite for fill and drain plugs. Saving this for future repairs. Currently @ about 235k miles

 

[donjetman]

Going with Felpro gasket and permatex black gasket maker combo.

You might want to use Permatex 81182 gear oil rtv: https://www.amazon.com/Permatex-81182-Gear-Gasket-Maker/dp/B0023GM2KK?th=1

 

[Just Fishing]

You will probably find like me, the rear axle has the molded rubber/steel gasket.
Those are reusable.

Just don't over tighten the bolts.