My truck has always been clunky on downshifts and coming to a stop I can see the tcase has excessive movement between the front and rear shafts. Also when I take it Offroad under a high stress situation when the wheels are spinning and grabbing traction again I can hear and feel a few loud popping noises that I’m pretty sure feel like the chain is skipping teeth.

Ive kept up on fluid changes and it has 140k miles. It also doesn’t leak. Is there any reason I can’t just replace the chain if there’s no other issues? Or is that asking for trouble? I’m not looking to sink a whole lot of money into this.

Is this easy enough to drop on the floor of my garage with a large jack? Or is there not enough clearance to get it out from under? I don’t have the u steps or anything to get in the way.

 

I had mine out about 6 weeks ago while doing the rear main seal on the engine. I have an inexpensive Harbor Freight transmission jack that helped out, but a regular automotive floor jack would work as well. After you disconnect everything and pull the bolts out, it's not going to drop or anything. You have to slide it back a little bit to disengage the splines. You will be sliding the tail housing back over that welding cross member that's in your way. Then you have to angle the front of the transfer case down onto a jack and then lower it. So make sure you've drained all the fluid first. And that's how I put it in. Tail shaft pointed up, raised it up with a jack and then laid the tail shaft over the crossmember. It's just a bit awkward. Not super heavy or anything. After I got it down I just dragged it out from under and lifted it up on my workbench.

 

I had to slide it off the Jack and onto the floor to clear my side steps to drag it outu

 

 

 

The most difficult thing with rebuilding transfer cases are the snap rings. Pick yourself up a large set of snap ring tools. Mine are 18 in Long and ratchets and position as you expand the snap ring to hold it open. Other than that it's pretty straightforward. The chain will cost you more than the rebuild kit. Assuming the hard parts are all okay, it's just a matter of disassembly and replacing the bearings and the chain and of course the seals. I have not dug into the transfer case on the Hummer yet, but it looks almost identical to some of the Borg Warner cases I've worked on.
it should have an oil pump that's included in the rebuild kit. Take pictures as you disassemble to refer to for when you put it back together. All of the bearings come out easy, nothing should be pressed on except for one needle bearing in a blind hole. You can pick up a suitable blind hole bearing puller said on Amazon for under $50. Individual parts are readily available for many transmission parts companies online.

 

Off the top of my head I think it is a Borg Warner 4484, but I won't swear to it. That's just from looking at the case. Anyway, make sure you only use an original Borg Warner transfer case chain. There are a lot of cheap Chinese ones for under $100. It is not where you want to save money.

 

Gavin, I rebuilt my 2007 Tahoe transfer case which was exhibiting the exact problem you are talking about. It too had about 160k on it. Like RobertDez has mentioned snap rings are the biggest pain in the ***. A genuine GM chain is the biggest cost and for some reason seems to be the part that causes the issue other then the shift forks. A transmission jack will be a must. I made a special jig when I pulled the case from the Tahoe but that case is lightweight compared to the BW4484 case used in the H2. Its a real monster an having one fall off the jack would be a real disaster.

I have watched a number of rebuilds on you tube and it seems that anyone who is mechanically literate wont have an issue with it. For the most part the things are bulletproof and the part that seems to see the most wear and tear is the chain. Break out the Amex Gold card, I bought a genuine GM about 3 years ago and it cost me close to $300 bucks! Its in the parts bin for my 08 when it needs it. I do know that Morse makes a replacement for under $200.00 and its a great product and one I used in the tahoe t-case project!

After I changed the chain in the Tahoe I was surprised how much difference it made. No more clunks putting it in gear as well as when shifting from drive to reverse just moving around in a parking lot and so. A slack chain in an AWD vehicle just sucks!
Keep us posted on your project! Snap some pictures if you can!

 

Thanks guys. I’ll update when I do it. At the moment it’s not the priority since the truck still drives fine. Just clunky. It only ever skips teeth when doors deep in a mud hole in 4lo. The oil leaks are so bad now I have to do something about it and the motor mounts have **** the bed too so it might be a while.

I’ve pulled a transfer case before but it was on a k5 with 37s and a 6 inch lift so there was plenty of room😂