I might need someone to verify before I go forward....


I spoke with a very knowledgable person at the Salt Lake Hummer Dealer. He said the first thing I need to do if I am going to keep wheeling like this is to replace my front and rear ring and pinion gears with Yukons (as in GM). He said either 488's or 513's. If this pans out.....we could have a fix.

F5fstop.....can you verify?

I'm not so sure I agree, Phil. If it spun the teeth off the ring gear while stationary, it means there was enough torque flowing through to the pinion to do the job but the ring was not able to handle the torque and make the tires break free and spin over. (this according to what everyone said happened)

A truck "should" have enough strength to break the tires loose if the truck is immovable without breaking something in the drivetrain as long as it's not a jerk on the drivetrain, ie dumping a clutch. Static load vs. dynamic load.

Now, I have no idea if going to a lower gear ratio would solve this if the gear itself is too weak to handle the load.

I'm not real sure about this one.

Bebe,
It was very clear to me that crawl ratio is not the issue here, it is gear material strength. It appears that the gears are too brittle for high impact driving, so the 'fix' would be a stronger material. As an example, the ring and pinion gears used in a 200 HP S10 Blazer 7.625" differential are exactly identical physically to an SS Camaro LS1 with 330 HP. The difference is that the Camaro gears are made for high impact driving. They are made to absorb the shock by being more resilient.

I would venture to say that GM will probably come out with a different material replacement R&P for vehicles with your 'symptoms'.

hey phil , bebe and i are wondering if they ment the gears for a yukon or gears from a company called yukon ?

and thanks for the input NoMo maybe we should be looking for a stronger material

thanks guys

still in moab drinkin beers

Interesting info NoMo. AAM has something called PowerDense ring/pinions they are using in the front (I don't know about the back). I don't like the idea of something that has to have a special name to do something it is already supposed to do.

Anyway, Phil, I think you and I are on the same page. I just couldn't necessarily see that a lower gear ratio would mean a stronger gear, but could see how it would break the tires free sooner, but that's as far as I could make it.

Here is a link to some more info that was started in the H3 tech section on this:

http://elcova.com/groupee/forums/a/t...1/m/9351068971

That is good advice, stronger gears of the same ratio is a far better idea than the dealers on of running 5.13's. </div></BLOCKQUOTE>

I would have to vote for stronger gears too. From surfing through this thread and many others, my first glance is a hardening problem. But I will see what I can find out...unofficially.

That is good advice, stronger gears of the same ratio is a far better idea than the dealers on of running 5.13's. </div></BLOCKQUOTE>

I would have to vote for stronger gears too. From surfing through this thread and many others, my first glance is a hardening problem. But I will see what I can find out...unofficially. </div></BLOCKQUOTE>

Thanks, I appreciate everyone's opinions on this.

Going from a 4:56 with 35" tires to 4:88's with 35" tires, may not make that much more of a difference. But I appreciate the comments. BebeRhino is my daily driver, however most of it is city, or congested freeways. No real need for high speeds.

As long as the Yukons are a stronger material, I may still look at this as a viable option.

Someone has to be a guinea pig

Just my 2 cents.....

4.88:1 with 35's puts you back to about stock with 33's so that sounds good. Problem is the lower (higher numerically) the gear the more teeth which equals less metal per tooth so in theory with all things being equal a 4.88:1 is weaker than a 4.56:1.

As I recall the H1 uses an AMC model 20 differential which was used in CJ’s etc……and not known to be the most durable differential in the world especially the two piece axles. The reason it holds together in an H1 is because they run a 2.56:1 or 2.73:1 gear ratio and multiply at the geared hub.

My opinion if people are breaking gears finding stronger ones is a good idea but I’m not sure going to a lower gear is the best idea. At least if it’s stock the dealer will warranty it for 50k miles.

Here is a shot in the dark but how close were the built dates on Neo's and Bebe's rigs? Could it possibly be that there was a problem in the production/hardening of these gears and by dumb luck, they both had gears from this batch? Sorry Bebe and Neo, just looking for a silver lining for the rest of us

Here is a shot in the dark but how close were the built dates on Neo's and Bebe's rigs? Could it possibly be that there was a problem in the production/hardening of these gears and by dumb luck, they both had gears from this batch? Sorry Bebe and Neo, just looking for a silver lining for the rest of us </div></BLOCKQUOTE>

My feeling is, this is likely the problem, and wouldn't afect most owners unless they're really pushing the truck hard. Something as straight forward as a high load ring gear failure would have shown up in preproduction testing if it was a design issue and not a manufacturing issue.

HummBebe

I missed the story on how you broke the gears.

Do you have an auto or 5-speed and do you have 35" tires?

KetKat is right about the 4.88's having smaller (more) teeth on the gears. Also with lower gears in the diff and bigger tires the cv joint might start to blow??

Also if you change out the front you have to do the rear (not under waranty) too.

I agree with the previous posts. You are going to be very unhappy with that high a numerical ratio on the road, unless this is for offroad use only. When you go with the stronger gears, everything needs beefing up in the drivetrain. Years of drag racing has proven to me, that EVERYTHING in the drivetrain must be compatible or the weakest link will break. I've seen universals twist off of driveshafts, transmission splines stripped, pinion gears without teeth etc. It's boils down to how fast you unload the torque to the drivetrain from the engine, and I would just go with stronger diff gears. Quaife will make you berylium hardened gear sets that are virtually indestructible, but they are VERY EXPENSIVE and then you have to wonder if the transfer case, tranny or clutch, driveshaft etc will handle that torque.

Hello all..new to forum first post but I thought I would put in my 2 cents. I am a Hummer tech in Sioux Falls SD. We have only had one H3 blow a front diff here. Actually happened on our Demo out on the test track. Truck had 800 miles on it. Got stuck in the mogals (snow and mud) we hooked a chain and pulled it out. Very little if any wheel spin but it was in 4low and as soon as front wheels got to solid ground all the torque was at the front and it shaved the teeth right off the ring gear. Last Dec. I was in South Bend talking to several other techs and at that time the only bigger things they were fixing was the front diff's. Like has been eluded to previously I believe the problemm is week material in the ring gear. I used to build and race 4X4's in the mud and clay of florida and we had trucks with a 1000 hp that never broke ring and pinions.

Here is a shot in the dark but how close were the built dates on Neo's and Bebe's rigs? Could it possibly be that there was a problem in the production/hardening of these gears and by dumb luck, they both had gears from this batch? Sorry Bebe and Neo, just looking for a silver lining for the rest of us </div></BLOCKQUOTE>


hey newbie , you may be on to something there , bebe and i both got our trucks early in the production run . not sure of production dates we have both had our trucks since aug. 05

hey dan , we were trying to get up a set of steps between waist and chest high a its a pretty gnarly obstacle . we both have auto's , adventures and 35's .

ther are alot of details in the h2 area under 06 moab thread .

still in moab drinkin beers

Here is a shot in the dark but how close were the built dates on Neo's and Bebe's rigs? Could it possibly be that there was a problem in the production/hardening of these gears and by dumb luck, they both had gears from this batch? Sorry Bebe and Neo, just looking for a silver lining for the rest of us </div></BLOCKQUOTE>


hey newbie , you may be on to something there , bebe and i both got our trucks early in the production run . not sure of production dates we have both had our trucks since aug. 05 </div></BLOCKQUOTE>

VINs are ok, but I would like to track the date stamp on the axles.

Thanks for the input and welcome to the forum. Now I have a question for you. Where the hell is there to wheel in FL?!?!

Not looking for mud runs but looking for good placed to get some all around wheeling fun in. I know there are more than a few of us that would like to know.

One question for Neo and Bebe, did you have traction control turned Off?
Also, was a front wheel in the air, and then it hit rock, or were both on the ground when the axle took a dump?

hey f5 , we were in low with rear locked tractin cotrol off message is always shown for me when in 4 low we were BTMing with all four tires on the ground .

thanks for the input on all this .

Sounds like the front diff is as weak as ARB were claimimg.

Can one say solid front axle swap?

-C

Thanks for the welcome Newbie. Most of what we did was mud runs but when we went out to play we used to camp and wheel in the Oceola national forest. Find a campsite, pick a trail and see where it goes. Obveously not as good rough stuff but we had fun. I had a 79 Blazer, 38" swampers 383 stroker and 4:56's. It would do a 200' mud hole in 5 seconds.

If mine broke when I think it did, I was doing the same thing. Only difference was I was on a dirt/gravel ledge, not on slickrock.

BTW, I got my truck last July, around the same time as Bebe and Neo.

Thanks, I have looked into going to Oceola.

Yes.
When the truck is in 4lo lock with the rear locker on, the Stabilitrak system is turned off. Both of my wheels, front and rear were on the ground. I was essentially crawling up when mine spun.

Oh sure, just repeat what I said

Not yet. But I had planned on getting them before going to Moab in August.

I personally cannot go into great detail on this subject. I can say that there are very few reports of broken front diffs similar to that in the photo from Bebe.
I believe, traction control is active until it is manually turned off. However, stability control is deactivated automatically when the transfer case is shifted into 4-wheel low lock. These are two different systems, even if controlled basically by the same computer.
However, if no one turned the TC off manually, then the TC was operational, and that solves that question.

It's apparent that there are is not some widespread issue with the front diffs. What's sort of wierd is that there were probably other things that Bebe and Neo did that one would think would have popped the ring long before they made it to the stairs that day.

I think someone on one of the threads probably hit on the likely issue. It sounds like maybe there could be a ring or two here and there that was not "hardened", or whatever the process is, to the degree others are and to where it should be.

I doubt we see this occur very often.

I don’t know if the gears were hardened correctly or not but I do know this has happened more then we have discussed. I can’t be specific but I heard about a couple of issues in the PHX area back in September.

People might not like me for this but I think the differential is too small. We are talking about a 4900 lb vehicle with 33” to 35” tires and a 56:1 to 69:1 crawl ratio. That’s a lot of traction, weight and torque multiplication for a 7.2” ring gear to handle.

A Dana 30 which is larger and is probably stronger than the differential in the front of an H3 is marginal in a TJ with 33’s. That’s why Rubicon’s have Dana 44’s front and rear and they run 31’s from the factory.

Someone mentioned SAS which is what I’m thinking although I’m not sure how feasible it is. High pinion Dana 44, 4 link and coilovers.

I love my Hummer but am not going to be left stranded in the Mountains. I'll fix the problem or get an H2 or H1 which I am seriously considering before I walk home. I can fix a tie rod on the trail but not a differential.

From all accounts you can count on your fingers and maybe toes how many times this has occured throughout all of testing and the thousands and thousands of vehicles that are out on the road now. If it was a stress reason, it's likely you would see the rings shattering. With the type of damage occuring it leads to a flaw in the gear itself.

This was not a grenading of the diff, this was spinning teeth off and is a completely different animal than what is normally seen.

A Dana 60 up front won't make any difference if the gears aren't properly hardened due to some impurity in the process.

I will promise you this. You do a SAS and get into other mods to do wheeling and you WILL be stranded because you are going to break something. It's just the nature of wheeling and you don't have the R&D budget that GM does to figure out what works and what doesn't at the cost of breaking things.

Blowing the front diff does not end your day. If you can do a SAS and fix a tie rod then you should be able to pull half shafts and the front driveline and drive it out in rear drive only.

there are alot of opinions going around . one thing is anyone not with us or not familiar with golden stairs are thinking we were just driving . these steps were vertical and waist to chest high . no one should ever try anything close to this alone . the only trucks we saw were rock buggies and seriously modded jeeps . it is rated the third hardest run in the moab bible this trail has broken 1's 2's an 3's now

loaner white 3 with a little bling

LMAO
come home soon

i dont want to come home man i want to get back to moab ASAP that place is amazing you gotta come with us in AUG.

August??? Holy Crapoli!

Its like the hottest time of year. Hot Hot Hot.

Correct, an H-1 uses esentially an AMC model 20, actually A very strong differential just got the bad name as you said the 2 piece axles were the problem. A model 20 has A 8 7/8" ring gear which is only an 1/8 smaller than A ford 9" just doesn't have A pinion pilot bearing to steady the pinion gear like the 9". As for using A lower gear ratio to try to increase strength is backwards. the lower the ratio the smaller the pinion gear gets and creates A new weak point but at the same time requires less input torque to rotate the tires so it's kinda A catch 22 situation.