Front Diff Issue? - PhilD, you there?

[PARAGON]

Those two items might be tied to each other. That bolt the rear mount for your front diff. If it is allowing the diff to move, you probably have tweaked the front diff some.

FWIW, mine looks similar but is not loose. There is a rubber bushing above and below that plate.

Maybe the leak is just a seal due to the tweaked diff, but you have a lot of fluid at the center, where the halves to come together and I haven't seen a seal leak to over there.

Chances are you have a seal on the DS leaking and also the halves are leaking where they join. They don't have a gasket and are just milled and bolted together. With the diff being alum. it's pretty easy to torque it. There are instances where the front diffs have cracked.

I had my front diff case replaced under warranty because they could not get the leak to stop at where the 2 halves bolt.

What makes the bolt come loose? They're bolts on an H2.... the come loose. I had front suspension bolts loosen on the way to Moab, I'll find an occasional bolt loosed up a bit now and then. It's just the torquing of the body and frame from being off-road, I guess.

[PARAGON]

Looking at that first pic of the leak, it looks like it could all be from the DS seal.

If you are still under warranty, take it in. If not, clean off that diff good and check the fluid in the front. Make sure to fill it. That way you find some clean fluid after running it a while and figure out where it's coming from.

Tighten up that bolt. There's a nut on top. Probably an 18mm or something along those lines.

[CO Hummer]

Originally Posted by PARAGON

Chances are you have a seal on the DS leaking and also the halves are leaking where they join.

......

Looking at that first pic of the leak, it looks like it could all be from the DS seal.

If not, clean off that diff good and check the fluid in the front. Make sure to fill it.

PARAGON,
Thanks for your help!! Now, a couple of questions.

(1) What the heck is a "DS"?
(2) How do I fill it? Top thing marked with red arrow? How do you know when it's full? How much to fill it).
(3) What brand/type of fluid do I need?

[PARAGON]

DS = Driver's Side

Yep, that's the check/fill plug. The other is the drain. Fill to the edge of that hole (a little is likely to run out)

It's in your Owner's manual but something like 80W Synthetic Oil

[PARAGON]

Wait and see what Phil says. It's probably worth it to drain all the front diff fluid and replace it with all new.

[CO Hummer]

I checked the bolts on the diff and tried to tighten them (from the PS ). The one near the rear tightened about 1/4 turn. The other were very tight and I didn't apply any more torque. That might do it!

I'm gonna wash it off, then top off the fluid. I'll see if it continues to leak. I just had the fluid changed in my diffs this spring. Man I feel like an idiot because it looks so simple to do myself.

[CO Hummer]

Ok,
I power washed the diff. It looks so clean I think I could sell it on eBay as new.

Owner's manual say to put SAE75W-90 oil in there. All WalMart has was this SAE80W-90.

Is this OK to put in there?

[CO Hummer]

Thanks Phil.

I was going to use the "220, 221 whatever it takes" philosophy, but I held off and didn't put any of the 80W in. I'm gonna get some Royal Purple.

The diff is so clean that I could eat off it right now.