1) What was the whine/noise thing a while back about the rear diff where they replaced it.

2) Anyone else spun out or broke either their front or rear diffs/ring/pinion/spider gears?

3) Which ring/pinion is in both the front and rear.... tooth count on the ring gear, etc?

I had my front diff replaced a few months back. It didn't completely shatter like Neo's or Bebe's but the tech told me there were some chipped teeth. I was gone while they were working on it so I couldn't check out the damage.

I still don't know exactly how it happened. I didn't even notice it until driving on the highway. Even then I was able to drive it for about a week before taking it in to the dealership.

Did you have trouble with one of the axles?

This the the best information I could obtain today.
Rear axle is either a AAM 800 or 860
AAM 800 - 205mm (8.07 inch) ring gear diameter with a TracRite EL rear differential. (If it is this axle, I stand corrected in my original post.)
AAM 860 - 220mm (8.66 inch) ring gear diam, with a TracRite EL differential.
Either one is cast iron.
Front axle
AAM 725 185 mm (7.28 inch) ring gear TracRite (think it is the GL series) with an aluminum casing.

Neo and Bebe's situation is very curious and makes me wonder if the slowness of GM to offer more power is associated with something along these lines or not.

There's one picture where it's obvious the pinion spun some teeth off the ring gear. It seems the same occured in all three instances on both trucks and that maybe even the I-5 is offering too much torque for this diff setup and the weight of the H3.

I would suspect if you tied 10 H3s to anchors and slowly applied the torque on a surface with good traction, several of them would spin out the ring gears if there was some weight transfer. This without the usual culprits of bouncing, over-spinning, etc that is usually associated with this kind of breakage.

Would a 2.56:1 transfer case consequently be better than the 4.00:1 one - delivers less torque in 4W-Lo?

All I can say is that the 3.7L will have the same axles; however, when the 5.3L comes on board, it will have a larger front axle for sure; not positive about the rear axle (but I did hear rumors about the next size up).
The overspinning when going over obstacles should be taken care of by the traction control system that limits the spin of the wheel in the air. Preventing the the well know axle grap...axle break or diff problems.

I really haven't heard of any problems with any of the axles other than the lapping compound problem. (I should say other than leaking drive shaft axle seals, caused by incorrect install of the axle. Hopefully, this was fixed by waking the guys up on the line and having them use the seal protector tool versus eyeing it. Easy fix at a dealer.)
I know the GM test guys did some hard testing on the vehicle prior to, and after vehicle launch.

The reason the I-5 was used was because at the time, it was the only engine available to fit in the compartment. The I-6 was too long, and production of the 5.3L was not up to the numbers they needed (and modifications were required to fit it in the engine compartment). The 3.5L was the logical engine to use, and GM has been blasted for the underpower of the engine by every magazine.
They had the 3.7L on the books prior to launch, but it takes a while to test, test and test. In a few months, the 3.5L will go out of production, and the 3.7L will take over.

I know the brand quality guy for this engine get reports everyday on any component that hits a certain number of replacements or rebuilds. This information comes from the dealers via the labor operation number for the part replaced.
This number is set pretty low, that is why with only 100+ cylinder heads replaced (out of over 100K engines on the road), the brand quality guy was all over the problem, working with engineering. Once the problem was found, the cylinder heads were stopped, which caused a shortage, and new ones with hardened valve guides were produced.

If I see a spike in the numbers (I get the labor operation number run once a month), I'll speak up.

I sure hope there is no problem, and this is just a fluke, but unless there VIN numbers are close, I can't see it as a quality spill from AAM.

Didn't know Neo and Bebe broke the front axles. Do you have photos. I would love to send them to the axle guru at GM and see what his reply is. I would be curious to see if he tries to pound sand up my rear or give me a straight answer.

I'm thinking, just thinking mind you, that everything was being lined up and there was no combination GM could put together that would offer a sufficient power plant off the bat that would match well with what could be produced throughout the drive train.

Maybe they needed to go with tried and true, as I'm sure something could have been done to accomodate a different engine in the design phase. It's a moot point anyway, just a thought.

I'm just wondering if the torque is too much for the diffs. Just odd to spin teeth off of 2 different ring gears, two different rigs, same day, etc.

There was a picture posted somewhere on here by someone from Moab and I think it was of Neo's diff. Maybe someone else remembers where it was.

http://elcova.com/groupee/forums/a/t...771084871/p/26

about halfway down. note: from the discussions (I wasn't there) this happened at the same place on the trail for both rigs.

interesting

it uses AAM calls their PowerDense ring/pinion set. Supposedly to offer more torque control in a lighter package.

Well, I get wary anytime a company has to call something a "special" name for something to do what it's supposed to do.

<H1 align=center>Technology Update: Differentials Provide Customers with
Improved Traction and Handling and Reduced NVH</H1>


DETROIT, March 3 -- The <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=American%20Axle">American
Axle</A> & Manufacturing
(AAM) TracRite(R)
differentials for both front and rear axle applications have been designed to meet a
variety of customer requirements for traction control and improved ride and
handling. The AAM family of differentials range from its current
industry-standard mechanical differentials, to its newest, most sophisticated
electronic traction-enhancing architectures. When coupled with the SmartBar(TM)
roll-control module, AAM's TracRite
differentials provide maximum traction and handling performance with reduced
noise, vibration, and harshness (NVH).</P>


TracRite differentials feature PowerDense(TM)
gear sets and net-shaped forged and piloted side gears for low lash and quiet
operation. Two of AAM's newest TracRite
differentials are the <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=TracRite%20EL">TracRite
EL</A> and <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=TracRite%20GTL">TracRite
GTL</A>.</P>


AAM's advanced <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=TracRite%20EL">TracRite
EL</A> features lightning fast (50 milliseconds) engagement and disengagement
and is lightweight and compact. It offers scalable high-torque capacity, low
electrical power and actuation that can be programmable, driver selectable, or
both, and is compatible with ABS braking.</P>


The <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=TracRite%20GTL">TracRite
GTL</A> is a helical gear differential with a locking feature. The locked mode
may be engaged automatically via a programmed computer, driver selection, or
both. The GTL continuously biases torque to the higher traction wheel to prevent wheel
slip, and features a tunable torque bias ratio.</P>


"We have engineered and designed a family of differentials to meet and exceed
our customers' expectations and needs," says <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=Daniel%20V">Daniel
V</A>. Sagady, P.E., vice president, Engineering
& <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=Product%20Development">Product
Development</A>. "Our line
of AAM differentials builds important performance advantages into our customers'
vehicles. For instance, an SUV equipped with a TracRite
differential in both the front and rear axle can provide true four-wheel drive. In some four-
wheel-drive applications, the transfer case can be greatly simplified, providing
significant advantages in packaging and mass reduction, while creating full-time
all-wheel drive."</P>


AAM is a world leader in the manufacture, engineering, design and validation
of driveline systems and related components and modules, chassis systems and
forged products for trucks, sport utility vehicles and passenger cars. In
addition to its 14 locations in the <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=United%20States">United
States</A> (in Michigan,
<A class=tspt
href="http://www.theautochannel.com/search/search.html?words=New%20York">New
York</A> and Ohio),
AAM also has offices and facilities in Brazil,
England,
Germany,
Japan,
Mexico
and Scotland.</P>


Certain statements contained in this press release which are not historical
facts contain forward-looking information with respect to the Company's
plans, projections or future performance, the occurrence of which involves risk
and uncertainties that could cause the company's actual results or plans to
differ materially from those expected by the company which include risk factors
described in the Company's
filings with the Securities
and <A class=tspt
href="http://www.theautochannel.com/search/search.html?words=Exchange%20Commission">Exchange
Commission</A>.</P>

Design phase started with the Colorado/Canyon. Unquestionably, it was less expensive for GM to design the vehicle around the same engine as the optional C/C engine, and then set up for a new set of axles, and diffs, etc.
Might not have been the correct thing to do, and I have to admit, looking at that destroyed differential, does not give me a warm and fuzzy feeling.

I purchased my truck on 6/30/05. But I think you already checked my VIN.

I purchased my truck on 6/30/05. But I think you already checked my VIN. </div></BLOCKQUOTE>

Not sure. But that only affects rear diffs, and if you have any substantial miles on the vehicle, you would know if that problem exists. The wear caused by the lapping compound made the axle very noisy. But, while your vehicle is in service, ask the dealer if they would pull of the rear cover and check for debris.

Here's the pic from the other page. I hope that it's ok that I post this. I just thought it would be nice to have this photo on this page.

that is bebe's front diff . i think mine probably looks about the same but mine is in salt lake . so we havent seen what it looks like with the diff covers pulled .


still in moab drinkin beers

It looks like a metalurgical problem the teeth don't look stripped or sheared off in the case of a high torque load, it looks more like they cracked off due to porosity (bad alloy mixture,bad casting or bad block of raw material if they are a machined and forged parts )

Is this covered under wnty? Sorry if this was asked already.

Better be covered under warranty.

Mine was replaced under warranty.

I think you are on to the answer. I am not sure what this new PowerDense entails but maybe it's new technology and there are imperfections that can occur.

Many times items are run through a heat/cool cycle to enhance hardness and durability and maybe the process allows for one in xxxxx amount to come amount improperly "cured."

Paragon - I hope you're right and I hope that means the new one they put in mine won't be prone to the same kind of breakage. **fingers crossed**

Only time will tell I guess.

I replace a fornt diff on an H3 2 weeks ago that looked exactly like this one and it was on our dealer demo with 800 miles on it. Happened on the test track at the dealership. Truck was stuck in snow and mud on the mogals, pulled truck back front wheels had traction rear wheels in snow and it chewed it up. No wheel hop not spinning wheels hard or anything.

Can you get the VIN and details to F5Fstop. It sounds like he might be able to track some of this or check it out more or whatever.

Haven't seen any issues with diffs in our shop other than the ones f5 was talkin about with the lapping compound in the rear diffs. Have had 0 front diff failures, could be isolated cases, possibly A bad production run, never seen A diff come apart like that without some serious driver abuse and A lot more torque and hp than an H-3 produces. I sure hope it does not become A widespread problem. As for warranty it should be covered but depending on your dealer don't offer info on where the failure occured. If ya told me you were blazing up A hill bounced over A rock ledge and kept your foot in it I would say to you "cool, lets get the general to cover it" but thats me. I would rather see someone use there hummer and have some fun with it and be confident the dealer will stand behind the product.

A couple of things to think about:

Were the rigs experiencing these issues Auto or Manual? You have to consider the torque convertor on auto when figuring the over all gear ratio... While the by the numbers ratio for a H3 with Auto, 4.0:1 TC gears and 4.56 gears in the axles the crawl ratio is about 56:1, when you factor in the Torque Convertor, you end up with approximaitely 100:1 ratios.

The next thing to consider: The front diff looks like its aluminum, which if stressed hard enough may allow for some case deflection. Possibly enough in high traction environments that you may start stripping off ring gear teeth.

I did this a couples time on a 9" Ford axle that was in the front my competition buggy using stock Ford 9" carrier. I stripped teeth much in the same way as shown in Bebe's picture. (Note, I also broke bearing caps which contributed to the teeth breakage). I did this 3 times before I installed a stonger case (Ford 9' axles use a drop out third member like Toyota axles).

The last thing to consider is that GM used a standard cut gear in the front which is well known to be weaker when used in a front axle application (vs a revese cut gear, think Hi-Pinion diff in the front). This is because the gears are running on the "coast" side of the ring gear teeth.

Add that to a fairly small ring gear..

I hope that this is isolated, but larger tires, lots of torque, good traction, heavy rig.... you might just be pushing the front diff past its design limits.

I hope not, because while my H3 is my DD, it will server some double duty as a toy and see Tellico, Windrock and who knows where else.

Jim O
www.etoracing.com
06 H3 Lux/Adv

I checked the data on our demo this is the build data for front diff. Build date on truck is 6/27/05 last 8 68114896.

Component Code : 63 - FRONT AXLE/FRONT CRADLE WITH FRONT HUB ASSEMBLIES
Source Plant : X
Part/Num Broadcast : UK5 Traceability : 16750177
Date Scanned : 06/27/2005 Time Scanned : 12.46.00 Scan Station : 06

That could fall in with the others that have had this issue.

How do you check build date?

You have a PM. Sorry to hear about your front axle.

The other two were built within a month of that date.

Off topic question on the front rear link replacements. Was this due to squeaking noise while going over bumps? I'm trying to track my squeaks, and I believe this is the areas where they are coming from.

I also had the squeaking noise look into as well. They said that it was caused by the 4 bolts that hold the front cross member(?) to the frame. All 4 bolts were loose and 1 he was able to unscrew by hand it was so loose. So, whenever the frame flexed over a bump, that's what was causing the squeaking noise.

Could build date be estimated by sticker on frame on drivers side between the 2 doors?

Mine says 06/20/06

I have pic dont think it will load?

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Nope Dam !

WoW...that's impressive!

New question:

What does HUMMER consider a normal measurement for Backlash???

The tech who put in my new R&P said the old one was at .022 (thousandths) and that normal was from .006 - .010.

He said he thought along with the possible inconsistency with the hardening process, that the backlash was way off. He shimmed it to .010 thousandths.

Shhhhhh.....no honey.

I don't think case deflection would be an issue up front with this IFS setup. Even if the axle case flexed I don't think it would to where it would pull the pinion away from the ring.

I say that, but I really don't have a clue what the freaking case looks like, but IFS has other points before it gets to the case to allow for any twist to be absorbed.

There is nothing standard about the front and rear axles. It's some new technology that AAM has come out with. The gears are made using what they call PowerDense material which is "lighter" but stronger, or so they say.

Apparently the torque load for this axle is well within specs for the H3 and would easily assume more torque from a larger engine or some type of forced induction, but it might be the weakest part of the driveline. It all remains to be seen.

HummBebe
Hummer Guru

Posted Apr 27, 5:58 PM
quote:
Originally posted by fourfourto:
Could build date be estimated by sticker on frame on drivers side between the 2 doors?

Mine says 06/20/06



Shhhhhh.....no honey.

T & A Affilliate
Fo T & A Monitor


HummBebe called me honey

Shhhhhh.....no honey. </div></BLOCKQUOTE>


Look at the date.....It hasn't even happened yet.

Holy Shiite! .022"?!?!? That's horrible!

I set mine up at .006" but acceptable is up to .009", that may explain alot. I wonder if the case is distorted, no way GM would allow that kind of excessive clearance.