H3 U-Joint/Drive Shaft issue?

[tslevin95]

Last week I got my drive shaft replaced (2 rear u joints connecting them are new), the mechanic forgot to put on a new front u joint so I noticed a vibration at high speeds while taking my foot off the gas (Chevy dealer said it was a bad front u joint). Was going to take the H3 back to the mechanic to install a new u joint in the front. Today while backing up I noticed a loud grinding noise when in motion (low speed) and when I turned the wheels, to the left or right, going forward or backward, my H3 came to a stop while my foot was on the gas.

Could this be due to the bad front u joint or the new drive shaft possibly being installed incorrectly?

Having it towed to the GM dealer in the morning, but hopefully looking for answers before then.

Thanks guys.

 

[4speedfunk]

Not likely. I'm guessing a t-case issue. Possibly a front diff issue.

 

[cgalpha08]

^what he said.

 

[alrock]

What he said.

 

[Happy Hummer]

May be. For instance if the ujoint fraged or the cv did possibly but not all to likely. I'd sure as he!! hope is was though. Lol. The other stuff they mentioned is pricey.

 

[4speedfunk]

My guess is something was wrong inside the t-case. The symptoms you describe leaving your driveway are classic signs of a stretched chain and/or loose parts inside the case.
Obviously something let go in a major way. I have not seen an H3 case turned inside out like that.

 

[06 H3]

letting your foot off the gas with noise or vibrations is usually pinion preload from a diff stand point. Dont count out the front diff

 

[tslevin95]

Just heard back from the mechanic at the Chevy dealer. There are a few problems. First, the front u joint is wobbling, so that needs to be replaced. Next the guy said that the transfer case has a leak and the transfer case control module and motor encoder need to be replaced.

They want around $1,500 for parts, labor, and disposal to do the repairs. Cleary that is outrageous, so I will purchase the parts (need to find the part numbers) and find a mechanic to install.

 

[4speedfunk]

Good luck with the repair.

 

[alrock]

I suspect there's going to be more to it than they said. Take it to a place that will tear down the transfer case and take a good look inside. Second, I don't see why the transfer case control module or encoder would lead to the issues you described. If you weren't changing 4WD modes the encoder should not be an issue.

One quick thing - do make sure your 4WD buttons are functioning properly and you didn't accidentally hit one of the other modes and/or two buttons are stuck down confusing the encoder.

 

[4speedfunk]

My t-case was doing the same thing. It would seemingly "jam-up" at start-up. Most of the time it would work fine but, every once in awhile...it would bind like hell at start-up. The buttons were fine. I could cycle thru the modes with no issues. But in 4HI-street, it would occasionally feel like it was locked. Fast forward a few days: It started crunching and munching and sometimes it was quite violent. I can remember coming to a stop several times, and feeling a very harsh, heavy, SLAM. One time I actually pull over because I thought someone had rear-ended me!

So I drained the fluid. It looked like that liquid metal cop from Terminator II....full of metal particulate. I immediately bought a new t-case from GM and swapped it out, since I knew the downtime would be weeks. Upon disassembly, I found the snubber had come loose and was bouncing around inside the machinery...causing havoc. Its made from soft aluminum, so there was not much damage to the gears. But the chain was stretched, and the snubber was gobbled up pretty good. The two steel screws were also loose and they had been captured by the magnet. I replaced the chain, snubber, and swapped out the plastic fork for an aluminum one (just for the helluvit), and called it done. I also replaced the small M8 bolts that retain the snubber with larger 1/4-20 studs and nylon locknuts. Since then, I have ran into this same identical problem on another H3 t-case...so its the first thing I think of when I hear the description. Early 06-07 cases did not have the snubber...and thus probably never have this issue.

The dealer's assessment sounds like a logical first guess. Mine was not leaking and only had 42K miles on it when it let go.

 

[alrock]

When mine started going, it bound up momentarily three times over a few months. Didn't realize it was the t-case at the time. Something was loose, maybe the snubber as 4speed suggests, but it only got in the way a few times. Until the last time when things exploded.

 

[4speedfunk]

Same here. I drove around for quite some time with only minor symptoms. I thought it was something else. I still didn't know for sure until I pulled the t-case off the tranny and onto my chest. While lugging it out from under the truck...I could hear loose parts rolling around inside it.
It sounded like $$$$$.

 

[reaper]

It sounded like $$$$$.

Hey-- I know that sound!!!