H3 differential problems

[frumaker]

I took my H3 to the dealer on Monday because I was hearing a noise in the front end that I couldn't figure out. I got a call yesterday saying the driveshaft was bad. today, I got a call saying they think the front differential is bad. Later today, they verified that the internals of the differential were "chewed up". they said that the parts are on back order and they have no idea when they will be in. I have just over 40,000 miles on the vehicle, is this normal? I also found that I have dented the skid plate that covers the front differential pretty bad so I may be looking to get a new one or building a stronger one. Any thoughts would be great. thanks

 

[06 H3]

Tell them you wanna see pics of the chewed up internals. I'd start there.

 

[frumaker]

I can go look for myself too. This is all covered under warrantee


FRU

 

[06 H3]

o ok cool. I wish I was in your shoes...I would say thats not normal for regular driving but for offroading I wouldnt be surprised.

What kind of sounds are you getting?

 

[alrock]

Considering the wheeling you've done, the aluminum case, the bad driveshaft, I don't think this is unreasonable. Not ideal, but jot unreasonable. That diff has received a lot of stress from a lot of different sources.

I just replaced that OEM skid for the same reason. Found it a bit interesting that the new one has vent holes in the vertical section right in front of the diff, presumably for cooling.

It may be beneficial to request a new diff housing as well. My rebuild lasted 30,000 miles (original failure was at 98,000) and I suspect the second failure was due to the invisible but present stress failure in the metal. This is what Bebe and Neo had to go through on 06.

And in the meantime start saving up for a CI carrier as an upgrade down the road.

 

[frumaker]

Well I have the 09 adventure so i was under the impression I have the ci differential case. Am I wrong? I have mentioned that I want a full swap but they r saying no. If it goes a while with no parts I will push hard for a full swap.


FRU

 

[rsc]

If they won't replace the whole diff and have no internal parts available, take it back and drive the piss out of it or push against a wall with the front until you grenade the whole front diff. Then they have no choice but to replace the entire unit. You're right though, you have the CI diff housing which shouldn't stretch, but then they didn't think the aluminum housing was stretching back in 06 and 07 either. If they won't warranty the housing I would look into getting an extended waiver to the warranty on the front diff for another 50k miles.

 

[06 H3]

Maybe Zach can chime in here iirc we all thought h3s after 08 had the CI diff but only the alphas or front locked 3s have em.

 

[frumaker]

I have the front locker


FRU

 

[4speedfunk]

This all sounds normal. But that doesn't make it any more tolerable. Many of us have had the same issues...some of us multiple times. The front axle is way undersized for a 5500lb vehicle. Even with stock tires, its at its limit for 4-series gearing. Having an optional 4:1 t-case nearly doubles the torque on the input side of the axles. Then adding big luggy tires increases the load on the output side. So you can begin to see the problem...no engineering degree required. Its just too small for this kind of off road use. A cast iron case is certainly better than aluminum but, its not near as rugged as it needs to be. There is no quick & easy upgrade, so you're stuck with replacing your broken junk with brand new identical junk.

The only real way to prevent a broken front axle is to be easy on the gas pedal, avoid tire-spin as much as possible, and don't apply too much power with the wheels turned to full lock. The H3's front end is fragile, and you must gently crawl over obstacles and let the computer do its thing. The tried & true (Jeep) method of backing-up and hitting it again with more throttle...will surely result in an exploded front end. Perhaps the worst thing about the H3's breakage is the full-time 4wd layout. Because you can't shut off the front axle...they tend to completely eat themselves before you can get off the trail. Minor breaks...turn into massive damage on the drive home. I suspect the only parts you'll salvage are the case, the drivers-side tube, and the stub-axle inside it. The diff itself, ring & pinion, bearings, seals, etc. are most likely all junk. Notice, I didn't include: half-shafts, drive-shafts, t-case, or steering rack...all of which are also subject to being damaged.

When you consider the labor and parts chasing to rebuild one...I agree that a completely new assembly might be the way to go. Hopefully the dealer will get you fixed up.

You are pre-approved for a second mortgage, right?

 

[alrock]

Fru, you are correct - the front lockers are in CI carriers. I mistakenly assumed you did not have a front locker

 

[SolidusJ]

Anyway to search if GM has a set of 4:56 ring and pinon gears on hand to install at the dealer or nation wide?

 

[4speedfunk]

Here's a complete breakdown via Yukon. Hit the purple "VIEW PARTS LIST" button in the upper right....

http://www.yukongear.com/DiffDetail...ypeID=5&Type=GM&DiffID=290&DiffName=GM+7.6IFS

I realize this isn't GM stuff but, given the situation...you might pass this to your service manager. Yukon parts are very nice...perhaps better than the OEM Brazilian/Mexican GM parts. I'm actually floored that GM is covering it under warranty, especially with a caved-in skid plate. You got a good dealer there.

 

[rsc]

Did you go to a Cadillac dealer or the GM place behind the old HUMMER dealer on 35? That GM place fixed my warranty issues a year ago but did not seem to want to fix any 'extras' although the service was good.

 

[SolidusJ]

Is the H3 still in the shop? We need to link up and hang out again and run some test with the LED lights.

 

[frumaker]

Hummer is fixed after a full differential rebuild and new driveshaft.


FRU

 

[SolidusJ]

Great to hear man, let me know when you got some free time.