New info on the Front Diffs

[Bully13]

Originally posted by PackerFever:
August??? Holy Crapoli!

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

Yeah! Gonna be great! Getting stuck and then sweating up a storm. Watchout for desert colored H1s

[ketcat]

I’ve been wheeling for a long time, have had a lot of 4x4’s from a variety of manufacturers, work in the auto industry and have seen a bunch of broken differentials. I’m not anti Hummer and or pro Jeep in fact as I mentioned the Dana 30 (and Dana 35) are probably not up to any type of hard wheeling with larger tires even when upgraded.

You are correct defective gear's in a Dana 60 or what ever can cause a failure. From what I have read we are all guessing what caused the problem, at this point it‘s unknown why they broke.

As I said before the front differential in my opinion is rather small for extreme four wheeling in a 4900 lb vehicle with 33”+ tires and a 55:1+ crawl ratio. Which is why I am considering an H2 or H1. Not that they don’t break, they do.

Pulling a driveline and half shafts is no big deal but I would still rather replace a tie rod. BTW I was not referring to replacing a tie rod on an SAS H3 or saying I was going to do one. I’m sure some off road shops will be or already are working on that. 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.

As for the type of terrain they were on when the diff’s broke I’ve been to Moab, in fact my first 4x4 trip with the H3 was to Moab June of 05. I’ve not been on the Golden Stairs but have heard about the difficulty and am sure you could break just about anything on that obstacle. I’m certain the H3 can go off road a bunch and never have a problem. I’ve been on a bunch of trails in AZ, CO, UT and ID with out incident. I'm not anti H3, I love mine!

[f5fstop]

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 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.

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. </div></BLOCKQUOTE>

[HIHUMMER]

Originally posted by Sewie:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">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. </div></BLOCKQUOTE>

How many miles do you all have on your trucks? I got mine on August 1st and am at 19000 miles. Seeing a pattern? I haven't been offroad since Tellico...but the noises started after that....hummmm...? How can I check the build date?

[ketcat]

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 rods 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.

[CO Hummer]

Originally posted by PhilD:
Hardly an osbatcle you'd expect to start blowing diffs on though. One may be expected, but two vehicles blowing stuff on the same obstaacle tends to make me think there is eiether a more general issue with drivetrain strength, or just bad luck.

I totally agree. There IS a general issue with the drivetrain strength. I was standing right there and I couldn't believe it when I saw what happened. Bebe and Neo hardly gave it any gas before I started hearing that ugly sound of the teeth breaking off. Especially Neo - he wasn't even up the part of the steps where both his front and rear were against ledges! Only his back wheels were pressed against the ledge when a little torque shattered everything.

Bebe was fully pressed against two ledges - both front and rear wheels. She had tried it a couple of times, and it snapped around the 3rd attempt. She was being very careful and I was getting on her about needing MORE acceleration. Ironically, when I was telling her about needing more momentum she said "I'm just trying not to break my truck". 30 seconds later....Snap.

Something must be done to beef up those diffs. If not, I would not wheel Golden Spike with an H3 again unless I planned in advance to winch up the H3's over the obstacles requiring serious torque.

[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.

[CO Hummer]

One other thing i noticed about the H3s is that they have NOISY rear diffs. At trail stops, I kept hearing noise that sounded like radio static coming from Bebe's rig. I had thought it was her CB and the squelch was turned up t0o high until she informed me that H3 rear diffs were very noisy. It was amazing how loud that rear diff sounds while just sitting there in park!

[CO Hummer]

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.

[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 PhilD:
Hardly an osbatcle you'd expect to start blowing diffs on though. One may be expected, but two vehicles blowing stuff on the same obstaacle tends to make me think there is eiether a more general issue with drivetrain strength, or just bad luck.

I totally agree. There IS a general issue with the drivetrain strength. I was standing right there and I couldn't believe it when I saw what happened. Bebe and Neo hardly gave it any gas before I started hearing that ugly sound of the teeth breaking off. Especially Neo - he wasn't even up the part of the steps where both his front and rear were against ledges! Only his back wheels were pressed against the ledge when a little torque shattered everything.

Bebe was fully pressed against two ledges - both front and rear wheels. She had tried it a couple of times, and it snapped around the 3rd attempt. She was being very careful and I was getting on her about needing MORE acceleration. Ironically, when I was telling her about needing more momentum she said "I'm just trying not to break my truck". 30 seconds later....Snap.

Something must be done to beef up those diffs. If not, I would not wheel Golden Spike with an H3 again unless I planned in advance to winch up the H3's over the obstacles requiring serious torque. </div></BLOCKQUOTE>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'm betting that you could take 2 others through there, under the same setup and conditions and not experience that same problem. I can also bet that GM is all over this right now and have even seen the pictures of the Neo's diff since a failure like this is so uncommon. It might fall back on trying to figure out in AAM's process, what could have occured to allow for the metal to not properly cure.

[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. ?

[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.

[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.

[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.

[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:
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. </div></BLOCKQUOTE>Well, I really, really don't like coincidences and I agree. But there might be a relationship to the two trucks through the front ring/pinions because their build dates are fairly close together.

Not knowing the entire process at the gear manufacturer, it's really hard to speculate further. But they are very into this potential problem and if it was systemic then more than the handful that have shown up would likely have occured.

I have to also question why Golden Stairs. I wonder if the front diffs heated up from the hard wheeling up to the stairs and that changed it's properties some. Undoubtedly, some of the other days would have stressed the diff as much as the stairs did at that time.

[NoMoGMPG]

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 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:
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. </div></BLOCKQUOTE>Well, I really, really don't like coincidences and I agree. But there might be a relationship to the two trucks through the front ring/pinions because their build dates are fairly close together.

Not knowing the entire process at the gear manufacturer, it's really hard to speculate further. But they are very into this potential problem and if it was systemic then more than the handful that have shown up would likely have occured.

I have to also question why Golden Stairs. I wonder if the front diffs heated up from the hard wheeling up to the stairs and that changed it's properties some. Undoubtedly, some of the other days would have stressed the diff as much as the stairs did at that time. </div></BLOCKQUOTE>

For some reason, the Stairs claim Hummer axles. We broke a halfshaft on Wednesday when tire spin/hookup occurred. Dan Mick told me once that more axles and t/cases are claimed on that obstacle than any other on the Spike.

Dave