Help! My Hummer hates offroading?

[rsc]

Took the wifes 109k mile, '07 base H3 out to play today in some gravel, sand and a little mud today. Drove great until after hitting the mud and started making grinding/popping noises. We were not locked up, staying in Hi-Unlocked. It seems to be coming from the center of the car, sounding like a broken cv shaft rubbing on itself. It gets faster with vehicle speed not engine speed and only grinds and pops when the driveline is loaded not when coasting in gear or in neutral. Hi-Lock, Lo-Lock or Hi-Unlocked was acting the same, even driving in reverse it would pop. Sounded like you could hear a ring to it like it was in the driveshaft at times. Both front CV's are okay, not snapped or popped out, the U-Joints are tight and the drive shaft has no play. Definitely not the shocks, springs or body mounts, etc. Although the crossmember bushing is shot and you can see the bolt move up and down when switching from reverse to drive, I can't see it moving faster as vehicle speed picks up. It did it on asphalt and dirt trails. The transfer case goes into and out of the 3 modes correctly and the truck is not binding in turns.

My guess is a stretched xfer case chain or something else inside there is popping. Since the xfer case is a cheap little slut that is about cheaper to buy new than rebuild, we decided to drive it home and get a tow if it grenaded itself. But...after a mile on the road the noise went away and stayed gone. I tried to replicate it near the house but it shifts in and out of the Hi/Lo ranges and drives just fine. It did the same thing to a lesser degree a month ago when we played in the mud and went away when we got on the asphalt. What gives??? Plastic shift fork? Chain stretch? Possessed?

 

[alrock]

I'm guessing a chain stretch and/or a broken piece getting in the way on occasion. I would further the test by doing the 4WD modes on asphalt because if you're not getting binding on asphalt then your t-case isn't working properly.

 

[4speedfunk]

Check your front driveshaft. There is a CV joint on the rear end of it, and they get noisy when they go dry....it makes that "tubular ringing" sound you describe. Look for thick grease flung all over the transmission tunnel and skid plate. Shine a flashlight rearward along the shaft and look toward the t-case. There is a tiny metal cup with a rubber boot in it, on the back end of the shaft (where it bolts to the t-case). Check that boot for rips...its very common to actually see the steel balls of the CV completely exposed and dry! If so...its junk. When you drive into the goo with no boot, it gets mud in it and gets noisy. Then when you hit the high-way, the mud flings out and it shuts-up (sort-of).

New t-case is not a cheap slut. She's a high-class escort...$1600 plus labor.

 

[SuperBuickGuy]

that sounds exactly like what mine sounded like when I broke my transfer case chain... 4speed is right, not cheap, however, I saved some big bucks by buying a rebuilt case I found on an online yard search (e.g. http://www.partshotlines.com/)... I bought the rebuilt because it was about the same price as fixing the t-case. I still have the case, it simply needs two parts a gear that got snapped when the links came off and a chain... IIRC, the gear was ~200 as was the chain.... at that time, I had trouble finding the gear.

and don't keep driving it!!!! you may get lucky and only need to replace the chain. in my case, I lost 2 links, one got caught by the magnet, the other jammed between the gear and broke the gear.... keep driving and you'll only cause more damage!

 

[rsc]

New t-case is not a cheap slut. She's a high-class escort...$1600 plus labor.[/QUOTE]
Damn, they have gone up in price since I last looked! Maybe I was looking at rebuilt prices vs new a year or two back but I don't remember new being that high. Ouch!

 

[Zach]

New t-case is not a cheap slut. She's a high-class escort...$1600 plus labor.

Damn, they have gone up in price since I last looked! Maybe I was looking at rebuilt prices vs new a year or two back but I don't remember new being that high. Ouch![/QUOTE]

They went up about $400 a few months ago

 

[4speedfunk]

That increase might be my fault. I scored one from my local GM dealer for $1150 in the crate. I blabbed-up this deal on the forums and immediately the nationwide prices jumped up to $1600. DOH!

 

[rsc]

Dang it! I'm always late to the party for getting the good prices. Anyway, I'll take a look at the front drive shaft CV boot. I can't remember if the boot was on it or not yesterday, I slept since then and I think that bit of information leaked out while I was sleeping. I don't remember any grease, just a lot of mud and rain water on everything. I'll pull it tonight and check it out, thanks.

 

[SuperBuickGuy]

FWIW, when I toasted my transfer case, it was driving along on a snow-covered trail a bit too fast. I hit a 12" tree and I think it stopped the front wheels at about 15 mph. What I should have done was hit the gas the moment I saw the tree .... alas, nope - was an expensive hit.

 

[rsc]

They say hind sight is 20/20. Unless I'm backing up on a tight trail, then I can't see for squat. :whoa:

 

[SuperBuickGuy]

yeah, but it was an expensive set of glasses... I would guess that the pinion bearing was put on its road to ruin in that same night of wheel.... adding it up - let's see, front axle $1400, transfer case $1400, right rear fenders $800... yeah, expensive set of glasses... however, I now have a front locker, so it's not all bad (I could have saved $500 on the front rebuild by using the open carrier)... still, was an expensive night.

 

[rsc]

I would have ponied up the extra $500 for the front locker too. Look at it this way, you were wanting to put in a locker anyway, right?

I crawled under the wife's H3 today, she's not lifted so it was getting to be a tight squeeze in winter clothing. That thing needs to be lifted. It also apparently needs a new propeller shaft, dust boot has a big rip in it. Time to call around for parts. Thanks for the diagnostic help CJ.

 

[rsc]

Looking for a new part online I see new/OEM, rebuilt/Cardone and a Cardone CV rebuild kit. I was under the imprrssion these were mon-rebuildable, how do you change this out? Is it a slip-on fit of is there a clip or bolt holding the joint on???

 

[reaper]

I would guess driveshaft. If it happens again you can put it into 4hi lock, remove the front driveshaft, then drive it (basically in 2 wheel drive) to see if it acts up, and you could always bring the shaft to a driveshaft place to check out for free. Also: for driveshaft issues, take the shaft to a driveshaft shop, they rebuilt mine which is heavily modified for high angles for only $250.

 

[rsc]

I was debating pulling it and driving in 4Hi Locked while I had a greasable one fabbed up, but am not sure my wife will do what needs to be done to keep the transfer case locked up or call me saying it won't move. It's her H3, I just wheel it for her on the weekends.

I debated taking it through the mud with the shaft on and then with the shaft off to recreate the problem but I think the torn boot was the root cause like CJ said.

 

[rsc]

Replaced the prop shaft/CV and the clicking I had been hearing went away, didn't take it through the mud but I'm sure that fixed it. Inside the ripped boot was a nasty, dry cv as expected.