New info on the Front Diffs

[CO Hummer]

Originally posted by PARAGON:
I am most assured of that. I honestly don't think soft shocks could cause the tie rods to bend that many times in one day. Unless she was wheel-hopping every time. Something had to be off, and it could possibly be a damaged centerlink or something.

I was standing next to the truck only on the 2nd tie rod break. Rox will admit that she deserved that one. She got to the top and I was yelling "STOP" as her rig started to bounce. She back off a second too late and and BOOM, busted tie rod. But by the third one......something was definitely wrong with rig. She barely started crawling up an a ledge and it snapped without any sort of bouncing.

[CO Hummer]

Originally posted by PhilD:
Should be no noise coming from the diff when in park, nothing is moving. Was it something vibrating inside?

It literally sounded like you had a radio on that was not tuned to station - sounded exactly like radio static. No rythmic vibration sound, just static sound. Bebe said something to the tune of "all the H3s diffs sound like this". Apparently it's a known thing. ?

[PackerFever]

Originally posted by CO Hummer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PhilD:
Should be no noise coming from the diff when in park, nothing is moving. Was it something vibrating inside?

It literally sounded like you had a radio on that was not tuned to station - sounded exactly like radio static. No rythmic vibration sound, just static sound. Bebe said something to the tune of "all the H3s diffs sound like this". Apparently it's a known thing. ? </div></BLOCKQUOTE>

I have not noticed noise like that on mine at all. But I have not been listening for it either. I may get a chance to go off road a bit this morning on my way over to South Park so I will letyou know. I will tryiin 4hi and 4 lo. I donot have a locking differential as far as I know in my five speed.

[NEOCON1]

thanks cranky , bebe should be home anytime now

[PARAGON]

Originally posted by CO Hummer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PARAGON:
The H2 did not bend 3 tie rods on Golden Stairs. It was on the entire trip that day, that at best is a 9 hour trail day of hard wheeling. Golden Stairs is just one short obstacle where the 2 H3s spun the ring gears.

Huge difference.

And....per Rox's recent posts in the Moab picture thread it looks like there is something else going with her entire steering configuration. That might have caused the fluke of 3 tie rods busting on the same trail. </div></BLOCKQUOTE>I am most assured of that. I honestly don't think soft shocks could cause the tie rods to bend that many times in one day. Unless she was wheel-hopping every time. Something had to be off, and it could possibly be a damaged centerlink or something.

[Sewie]

Originally posted by NEOCON1:
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 .

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.

[FormerJeeper]

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

Can one say solid front axle swap?

-C

[f5fstop]

Originally posted by NEOCON1:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by HummerNewbie:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by f5fstop:
...my first glance is a hardening problem.

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.

[ketcat]

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.

[HummerNewbie]

Originally posted by cestwick:
I used to build and race 4X4's in the mud and clay of florida ...

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.

[cestwick]

Originally posted by f5fstop:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PARAGON:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by HummerNewbie:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PARAGON:
...But there might be a relationship to the two trucks through the front ring/pinions because their build dates are fairly close together...

I agree completely especially since there are now three since HI's has to be replaced. I would really like to see some investigation into this since the three vehicles that I know of with this problem were all purchase right at the same time. Of course any one of them could have been sitting on the lot for a while but I really think this needs to be looked into. Based on VIN numbers I would think it would be fairly easy to check the lot numbers for the gears in each truck. If the lot numbers are all different then that probably counts out a hardening issue but if they are all the same it would narrow down the possible problems in my book. </div></BLOCKQUOTE>I promise, it's being investigated. </div></BLOCKQUOTE>

Oh yes, it is being investigated, and maybe some more.

A few notes on other comments.
The axles already come with synthetic fluid, and the fluid is not the problem. The problem appears to be hardness.

Does GM put the minimal parts in the vehicle? Yes and no. The specs on these axles was high, whether or not AAM is cutting corners remains to be seen.

They won't put the largest axle available, for that would be a waste of money, but they won't put the weakest either; especially in something they know will be off-roaded by a certain number at places most would mess their drawers thinking about.

All I can say on this board is that as the numbers of destroyed axles rises, and as of yesterday, there were very very few, people will start asking questions. The three that we have on this board have not hit the warranty reports until the repairs are completed, and the dealer submits the labor op for payment. That is how the warranty numbers are run by engineering.

I can say, that some are raising their eyebrows with just the one photo I sent to engineering and mentioned there were two of these on one day. Tomorrow, I will let them know there are three that I personally know of.

If they jump on this like the cylinder head issue, it will not take many more to explode. The cylinder head issue was researched and the head re-designed with an extremely low number of failures; especially considering the number of these engines are on the road since '04.
I can't say for sure, since I'm low on the totem pole, but I would bet if there is a problem found, there would never be a recall, due to the low numbers of axles that will be replaced. However, I would bet a lunch, that if a problem is found, new axle specs will be established, and these new axles will be put into production, and shipped to service parts, so that the replacement axles, if needed, will be the stronger axle.

That is all I can really say on the matter; except please stop breaking your H3s. For some odd reason, when something big happens on one of these vehicles, I get pushed into the middle to help the situation, and I'm already busier than a one legged man in an ass kicking contest. (I'm trying to be funny... ) </div></BLOCKQUOTE>

f5fstop
I am sure we still have the front diff I pulled out could you use a pic of it as well? I know it looked almost exactly like The pic on here.

[ChasH3]

That true too... I'll just have to carry more beer along just in case.

[CO Hummer]

Originally posted by PARAGON:
It's looking like this is not systemic problem. Already, it appears that some ring gears can possibly make it through the system into the front of the trucks without proper hardening for the harder type wheeling that Golden Spike requires.

I don't know.....that seems like too great a coincidence that both trucks would have the same metallurgic problem, both would experience the same effect on the exact same obstacle, etc.

[PARAGON]

Originally posted by ketcat:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PhilD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ketcat:
I was saying that I am thinking of getting an H2 or H1 and that I would rather bent a tie rod than blow a diff.

Why do you think something in the steering will blow befor something in the driveline? While there is a realtionship, I've seen H2 diffs blow with vehicles with stock tie rods and there was no stress on them at all. Likewise, the H3 tie rods are hardly beefy, and they did not blow instead of the diffs.

The concept that the tie rod is a pressure relief valve for the drivetrain is a false one. </div></BLOCKQUOTE>


From what I read an H2 bent 3 tie roads and two different H3's broke differentials. Not saying one would go before the other just the difference in the experience they had with two different vehicles on the same obstacle. </div></BLOCKQUOTE>The H2 did not bend 3 tie rods on Golden Stairs. It was on the entire trip that day, that at best is a 9 hour trail day of hard wheeling. Golden Stairs is just one short obstacle where the 2 H3s spun the ring gears.

Huge difference.

[cestwick]

Originally posted by f5fstop:

Not easy that is for sure. However, there are four large bolts securing the hub to the knuckle and these bolts are torqued at 180 N.m each. The tire is then attached to the hub. I have never tried it, but the vehicle should be able to be driven without shafts.
The shaft torque is actually 235 N.m (ball buster). The torque is high since the shaft is fairly large.

I may just try this, because I'm not too sure if you really have to remove the knuckle completely. You might (as someone stated) be able to remove the tie bar and get enough swing on the knuckle to slide the shaft out. Happen to have a Hummer on the rack with the cylinder head out.

Maybe if the shafts were weaker, the shaft would go before the diff. (Then we could call it a Jeep )

I guess, if you had a metal saw, and didn't mind the extra 200 or so for the shafts, cut 'em and remove. That would be an easy job. [/quote]

Not that it matters but I am not sure where you got your shaft torque figure. This is out of SI for the H3.Fastener Tightening Specifications
Application
Specification

Metric
English

Front Wheel Drive Shaft Nut
260 N·m
191 lb ft



I have done an axle swap and tried just turning the knuckle and just undoing the upper ball joint but was just fighting it so did the bottom too.

[ketcat]

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.

[HummerNewbie]

Originally posted by Alec W:
You have 35s too if I am not mistaken?

I have my opinion and think the H3s drive train is weaker then the input power vs. output resistance. But… I wonder if 35s is what’s making the difference.


I guess time will tell us.

Oh sure, just repeat what I said

[PARAGON]

Originally posted by HummBebe:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PhilD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by HummBebe:
I don't think we can do that on the three's, has something to do with the computer thingy.

Bet you can, even if you have to start pulling fuses until it works. </div></BLOCKQUOTE>

Ok, we discussed that on the trail with the HUMMER mechanic.....I called him 2 seconds after I was off the trail....to order parts :-)

He mentioned that Stabilitrac would/could prevent the whole vehicle from operating if disabled.

That was honestly the first thing I thought of, I just wanted to go home </div></BLOCKQUOTE>You can simply pull the half shafts and front driveline without pulling any fuses.

All of the traction control, Stabilitrack and ABS runs off of the wheel speed sensors and maybe a sensor at the output shafts of the t-case.

If you are moving the wheels are are all turning and the computer doesn't know if power is going to the front or not.

[NEOCON1]

thanks dave , it was a great expierience to wheel with you .

would it be a councidence if a thousand jeeps went thru and 150 busted the same part , this is a risk we all take . Dan Mick and Dave speak the real deal about moab .

we werent just hoping curbs at the mall

phil in trucks built up like yours you should make it in 4 hours LOL