Transmission, Transfer case, and Differentials

[cory9oh4]

I've attempted to search around and found a couple things but they somewhat contradict each other. I need to do a drain and fill.
2008 Hummer H3 3.7L

- Does the transfer case and transmission take the same fluid? If so, what do you all reccommend and to confirm the transmission takes about 5qt and the transfer case 2qt?

- What oil do you all reccomend for the differentials. Are they 2qts front and 2qts rear?

If this has been answered a million times forgive me. I'm new to forum use and did my best to locate the information before aksing my petty questions.

Thanks,
Cory

 

[Graham2990]

A member of the forum has a site where's he's uploaded a complete service manual for the H3. Also makes some parts as well. Great resource I found out via this site when I first got my H3. I believe it's listed for a 2007, but most data is applicable to other years.

http://schwarttzy.com/wp-content/uploads/2013/01/Hummer-H3-Maintenance-Lubrication.pdf

 

[alrock]

Transfer case and transmission both use Dexron VI. T-case is about 2 quarts. A drain and fill on the transmission was about 6 quarts, if I recall correctly. Diffs take 75W-90 synthetic, a bit below 2 for the front and a bit over 2 for the rear. I would recommend having a fifth quart handy as you may use some of it.

 

[Renagade132]

Purple stuff is the best out there

 

[Panzer07]

^x2 on the royal purple products I run them on everything but the transmission and transfer case since they don't make a dextron VI or at least not that I'm aware.


Torres

 

[cory9oh4]

Thanks everyone for the speedy replies and information!

Any reccomendations on the Dexron VI brand?

 

[Panzer07]

I been running valvoline or something like that...so far has work great not transmission problem nor T-Case. As long as is dextron VI synthetic you should be fine. You might want to double check with royal purple and see if they make dextron VI in my books is the best oil out there...pricey but a cheap insurance for the long run.


Torres

 

[scoreh3]

Check with your local dealer or your owners manual , I was told ( and my manual said ) my 08 t-case uses manual transmission fluid . When I asked the dealer why some auto parts places say dex VI and others say manual trans oil , they told me GM changed t-cases in 2008 . At 50k I did front/rear dif's and t-case with Royal P and the trans with dex VI ( they don't make the purple stuff in dex VI yet ) . Oh when I drained my t-case that was not aft in there . I'm now up over 80k and no t- case issues . So if you have an 08 check your manual and the dealer to make sure .

 

[chaos254]

I did Mobil 1 for front and rear diffs, redline MTL for my transfer case

 

[4speedfunk]

GM has its own special fluid for the H3 full-time T-case, and it varies depending on the year. Something changed between 2007 and 2008, so check your owners manual for your specific GM Part number. There is so much net-chatter on this topic...you'll never get the straight scoop. Some say its DEXIII. Some say its DEXVI. Some say its MTF. Some say its its own critter. Some say that DEXVI supersedes all of those. Then there's the whole aftermarket lube debate that Amsoil, Royal Purp, and Lucas all exceed whatever juice GM says to use.

Long story short...if you have any doubts, just get the GM stuff listed in your owners manual. HINT: Type the GM part # into Amazon or Summit Racing and its much cheaper than your dealer!

One thing I do know for sure (and most will agree)...the 3393/3394 is a weird transfer case, and the fluid needs lots of attention. I change mine every 20K miles.

 

[Graham2990]

In my '08 I used Valvoline Dex 6 Full Synthetic ATF in the transfer case and Syntax 75-90 Synthetic gear oil in the diff's.

I believe my '08 is a later year build.

 

[rollerlocked]

For the front and rear differential I used redline 75/90 gear oil (pn 57904) , for the transfer case I used redline heavy shock proof (pn 58204) , and for the transmission I used ac delco 88861037. I'm rolling on about a year since last drive line maintenance and will use the same again.

 

[cory9oh4]

Thanks for everyone's input!

 

[jorallo]

transfer case fluids

I used 75-90 lucas front and rear diff. as for transfer case 1 lucas automatic trans additive with the rest of the fluid being synthetic dex 6

 

[digglesworth]

I use RP as well. Max ATF in the transfer case, 75-90 in the diffs. I used a synthetic dex vi in my last trans fluid swap.

 

[Best4x4]

Yep I slapped some RP Max ATF in both my H3 Transfer Cases and I used RP 75/90w in the Alpha's F/R diffs.

 

[tnd2]

I used Redline 75w90 GL-5 gear oil in the diffs, and Redline D6 ATF Dextron VI synthetic in the transfer case. It's been 11k miles and the fluids still looked clean 1k ago at the last engine service.

 

[Mb30sdl]

I prefer Mobil 1.