What kind of fluids and how much for the front and rear? Anything else I might need to complete the job. Thanks!

 

I can't remember the differential oil capacities, exactly. But, I think 4 quarts would do it. Pretty sure my Front took about 1.5 qt's. And, the rear a little more, ~2 qt.

As far as type of OIL. Here is my 2cents... But, It is up to your budget.
A synthetic is going to give you a little better fuel econemy (maybe not enought to notice) and a synthetic will handle temperatures extreems better (if you tow a heavy trailer or live in the frozen tundra). But, if you off road, and spend some time in the water, and need to change it often to get the water out. I would use a non-synthetic 80/90wt. 140 weight if you tow a trailer...

If you have added a limited slip differential (not stock) then you will need to add a friction modifier (if your choise of oil doesn't already have it added) to the oil, or the clutch plates will be noisy.

FYI, I have Eaton Electric Lockers Front and Rear and I used Royal Purple Max Gear 80/90, Full Synhetic.

 

All the information you need is in your Owners Manual. If you don't have one, they can be downloaded from Hummer.com FYI, all H3's came from the factory with synthetic differential oil. It is a very easy project to do. Good luck.

 

Agree^

You definately want to use synthetic lube as recommended in your owners manual.

Front takes about 1.5 quarts, rear is right around 3 quarts.

Do a Gooogle search as there are plenty of write-ups on this very procedure.

One last tip- Float the un-opened quarts in a bucket of the hottest setting tap water while you are getting everything ready and the lube will flow so much quicker.
Use 10" length of rubber hose to slip on the bottle nozzle and put the hose into the fill hole, then you can flip the bottle upside down and it will fill nice and easy.

 

Also be prepared for the garage to stink if you spill even a small quantity of the gear oil. Last change I bought some Royal Purple and paid the local oil change place $40 to drain & refill. More than worth it for the decrease in spousal dissatisfaction relative to the smell.

A hand pump also helps a lot if you do the job yourself. Took me about 1.5 hours, start to finish.

 

have you had any problems using 80/90...i had to replace bearings in my 06 with 62000 on it using 75/90 mechanic seems to think it maybe 75/90 ...ty

 

I have not had any differential bearing problems. Fingers crossed.


I did get into some pretty deep water... So, I flushed the diffs with standard Valvoline 75/90. And, kept the non synthetic fluid in there for part of the winter.


On the really cold mornings, 15*F or colder, and only in the first mile, driving. My front electric locker would sometimes engage by itself in a corner tearing my steering wheel out of my hands.


The drag of the really cold, non synthetic, gear oil can be enough to energize the Eaton eLocker that is OEM on the H3. It was fine, once the diffs warm up a little (which doesn't take long).


But, I almost took out my neighbors mailbox... I wasn't expecting it to straighten out of the turn (in the middle of the turn) that quickly...


That Said, I now strongly suggest Full Synthetic Gear Oil.


I have also upgrade to ARB Air Lockers... .

 

thanks for reply....i always ran 75/90 syn and this happen ...wondering if i should go with 80/90 syn ..mechanic seems to think 75/90 maybe to thin ..you were saying that you were running 80/90 syn and it seems you had no trouble thinking i may go with 80/90 syn ....ty