hey guys! i have a 2003 hummer h2, looking to change the front diff, rear diff, and transfer case fluid.

i see that the front and rear diff are 75w90 synthetic. So im thinking about using amsoil severe gear 75w90 for both.

also the t case seems to be a borgwarner 4484? seems like the recommended fluid is Dexron III NOT VI.

1. is severe gear fine for the diffs? or does hummer recommend gm fluids
2. do i need to add any ls additive in the diff fluid?
3. amsoil dexron iii is good for the t case? or use gm fluid?

its either between amsoil or royal purple for me!!! amsoil is a bit cheaper so leaning towards them. for rp i would probably do there maxgear 75w90 and then there synhcromax im guessing?


thanks!!

 

Amsoil makes great fluids. The sever gear fluids would be fine for your diff's.

How about Amsoil Synthetic ATF for the transfer case? Might as well put it in the trans while your under it.

 

Google the GM manual for your year truck even though they should be the same and look at the recommended fluids, that's what I went with when I did mine.

 

After my buddies H2 tcase was found with a pile of metal shavings when opened after using recommended transmission fluid,, starting at 78K miles, I change my front, rear diff and tcase oil every 30K miles with 75w 90 gear oil. At 258K now with no issues.

 

Amsoil in my Diffs and transfer case. I also did the power steering fluid, A brake fluid flush is super important while you are under there.

 

Just changed my transfer case fluid. When I drained I got almost 3 quarts of fluid out. But when I tried to fill the required 2.5 quarts it only took a little less then 2 until it started pouring out. Is that something I should be worried about

 

You got 3? Transfer Case Oil Capacity Borg Warner 4484 1.5 quarts

 

Yeah it was odd. So I’m only suppose to have 1.5? I filled up almost 2 quarts

 

I changed the tc with Dexron atf 3 h spec. I heard that we should use gear oil. Is there anything bad with using Dexron?

 

idk if we should use gear oil, i know we are supposed to NOT use dexron vi.
i used royal purple manual transmission fluid, seems to be a replacmenet for dexron 3 and a bunch of people on youtube are using it for our trucks