Loud whine from????

Hey guys, I need some help. 2005 H2 SUV

i've got a loud (ish) whine coming from somewhere ??? Sounds like the front seat forward but I can' t pinpoint it.
i can hear it from inside but rolling down the windows doesn't help. I, ve had my son drive it while I walked along and also rode on the running board to about twenty and still can't hear it from outside. Anyway, I've changed the front/rear diff fluids and TC fluid. The front diff was the worst looking with a few metal chips (about the size of a grain of wheat) but the truck has 177k on it and who knows if it's ever been checked/changed. The cv joints look good ( no grease slung, boots look good)
the noise happens when I am accelerating ( any time foot is on pedal) and subsides when I let off so I'm ruling out wheel bearings.
i have about 30degrees of "lash" in front driveshaft, not in the u-joints(up and down and side to side they feel fine.
is that excessive?? Wouldn't that mean both the TC AND the front diff are bad if not?
can I remove the front driveline and drive it and see if the noise goes away? Will it hurt anything? The front diff will still be spinning right? Just wondering if it will tell me anything, but as
Long as it won't damage anything or throw codes or ???? That's my next step, thanks for any help

the transfer case has a limited slip differential in it. The front differential doesn't thus, the transfer case would be fine with a bit of movement, the front differential - not so much. Pull the cover on the front differential and report back.

I have to split it don' t I ?
this is an H2

Correct, the 2 does not have a cover. You would have to pull it and open the case.

Thanks guys,

Do you think pulling the front driveline and driving it will help me find the noise?

Couldn't/shouldn't hurt huh?

You can try pulling the front prop shaft and a half shaft and drive it in hi lock

OK
new to the H2 and AWD, pretty green all around actually. First, what is the prop shaft?
I'm pretty sure you are talking about the cv joint from boot to boot by the term half shaft...right?
what would that tell me, or what would the difference be (meaning what turns/doesn't turn etc.)between that and pulling front driveline?

I'm not sure what pulling the driveshaft will get you - the front differential will still turn while you're driving.

and yes, split the case, it's really not that terribly difficult - keep this in mind, the only reason I say split it is because there is no reason you should have any metal shavings in the oil. If there are, this is something damaged.

OK, I just didn't want to do it unless I had to. Still trying to pinpoint the noise. What are my options if I find the front diff is gone? After a quick internet search that reman or new part looks like it might not be available. Are there any other aftermarket direct fit replacements I should consider?

oh, and thanks guys

p.s. I just bought the H2 and Love It!!!! Finding parts and info is a bit "tedious" and this forum is a great resource.

From GM, there is no replacement, you would have to rebuild it. Luckily, you have a 05, it has a stronger case than earlier years. If you're looking for a replacement, might want to try jasper. They carry a pretty good warranty as well

If you want a complete front diff sax-express carries them. If your case is good then the insides can be rebuilt using a master install kit from g2 gears and pickup another factory differential are upgrade to a eaton e locker and some new gears.

Thanks guys, like I said I'm having trouble searching for one using Hummer, I'm assuming its a gm part, is there a part number or is it the same one out of a suburban, or ????

i did see that eaton e- locker somewhere, is it direct replacement? Would I have to run wiring and put in a switch?
just trying to weigh my options, before I pull it.
how hard is it to pull? I'm doing this in my driveway, so far anyway

H2 is by itself. If you add the elocker, you would have to run wiring

My money is on typical GM alternator whine. Freaked me out when I first heard it on my H2... now I pretend it is a supercharger.

Can you post an audio clip of the sound?

I've got it out and removed the big plastic plug and can see the ring gear and there is like four (I'll call them pinion gears) gears that all look pretty good. No missing teeth, no slack or slop up and down or side to side on either axle nor the yoke end. I pulled the drivers side axle to replace the seal and don't see anything out of sorts. I think I'm gonna put it back in and move on to ????
autumn walker, I'll try to get an audio of it this weekend, the noise is pretty loud but you give me something else to at least check.wouldnt it rise and fall with rpm though? This sound only does it while pushing on the throttle under load, not in neutral or coasting or revving.
does anyone know if the front driveshaft is splined or ??
will it just pull out and I can drive it without it in and then just slide it back in? I don't even know if that will tell me anything but I'm just trying to find the damn noise
thanks again