New info on the Front Diffs

[HummBebe]

In either case I personally would wait and see if more differentials break because it's under warranty now and once you install aftermarket parts the warranty is gone. If it ends up being a bad gear issue and not related to the differential itself then upgrading is probably a safe beat

Well if the 35" tires don't affect the warranty....really.

Then changing the R&P shouldn't?

It is a minor modification to a inexpensive part.

Why not?

[f5fstop]

All H3s have 4.56:1 gearing.
Now, as for replacing the R&P, the only warranty item that would be affected would be the axle itself. Some overzealous service managers might say a better gear would affect the axle shafts, but my answer to that would be BS. Besides, if you did break an axle shaft, no tech will be removing the cover to see what R&P gear you are running, and most wouldn't know the differnce if they did.

[HummBebe]

Originally posted by f5fstop:
All H3s have 4.56:1 gearing.
Now, as for replacing the R&P, the only warranty item that would be affected would be the axle itself. Some overzealous service managers might say a better gear would affect the axle shafts, but my answer to that would be BS. Besides, if you did break an axle shaft, no tech will be removing the cover to see what R&P gear you are running, and most wouldn't know the differnce if they did.

[cestwick]

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 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. </div></BLOCKQUOTE>

I'm not sure if any of you have ever pulled a front shaft on the H3 but it isn't the simplest job to do. You basically have to pull the front knuckles off to get the shaft out. Also I'm not 100% positive about the H3 at this time but I do know that on most GM 4x4's the outer joint assembly is what holds the hub/bearing togather and is actually suposed to be tightened to 191 ft lbs. I have seen where the drive shaft nut wasn't tightened and the bearing went out in a very short period.

[cestwick]

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 cestwick:
I'm not sure if any of you have ever pulled a front shaft on the H3 but it isn't the simplest job to do.

Even easier if you've blown a CV.

You basically have to pull the front knuckles off to get the shaft out.

Can't you just disconnect the tie rod and swing the knuckle around. That is what you do on a H2, but I haven't looked at a H3 close enough to see if it would be the same.

FWIW The H2 axle nut is only torqued to 155 lb/ft and requires a 35mm socket. </div></BLOCKQUOTE>

No you can't. On the H2 you have the luxury of a halfshaft that bolts to the diff. H3 the shaft goes into the diff housing. Not enough room to turn knuckle and pull shaft.

[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.

[HummBebe]

YES PLEASE!!! the more the merrier or is it....misery loves company?

[PARAGON]

Originally posted by cestwick:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">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. </div></BLOCKQUOTE>you damn skippy

get some good ones too, like from an angle and chit.

[PARAGON]

Originally posted by cestwick:
<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 cestwick:
I'm not sure if any of you have ever pulled a front shaft on the H3 but it isn't the simplest job to do.

Even easier if you've blown a CV.

You basically have to pull the front knuckles off to get the shaft out.

Can't you just disconnect the tie rod and swing the knuckle around. That is what you do on a H2, but I haven't looked at a H3 close enough to see if it would be the same.

FWIW The H2 axle nut is only torqued to 155 lb/ft and requires a 35mm socket. </div></BLOCKQUOTE>

No you can't. On the H2 you have the luxury of a halfshaft that bolts to the diff. H3 the shaft goes into the diff housing. Not enough room to turn knuckle and pull shaft. </div></BLOCKQUOTE>sawzall?

[PARAGON]

What about just dropping the lower control arm?

In a had-to situation, I'm talking about. And mind you, I have no clue and am just thinking out loud. But if you get the ball joint undone and can get the knuckle turned and then move the whole upper control arm and knuckle up, would you have enough deflection along with the CVs to get it out?

[f5fstop]

Originally posted by cestwick:
<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 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. </div></BLOCKQUOTE>

I'm not sure if any of you have ever pulled a front shaft on the H3 but it isn't the simplest job to do. You basically have to pull the front knuckles off to get the shaft out. Also I'm not 100% positive about the H3 at this time but I do know that on most GM 4x4's the outer joint assembly is what holds the hub/bearing togather and is actually suposed to be tightened to 191 ft lbs. I have seen where the drive shaft nut wasn't tightened and the bearing went out in a very short period. </div></BLOCKQUOTE>

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.

[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.

[cestwick]

Just got back from talking to Parts manager. Was going to get pick of broken diff but we had to send it back to gm. Good indication they are trying to figure out what is going on.

[f5fstop]

Originally posted by cestwick:

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.

Opps; mine was off the engineering drawing which is lower. The 260 N.m is the correct spec for repair.

[f5fstop]

Tire front drive shafts are a beotch to remove, but can be removed from the
vehicle while in the desert.
Disconnect the ABS sensor under the hood, and at the upper control arm
remove the wire from the clip (prevents breaking the wire).
Remove the front axle bolt.
Remove the tie bar from knuckle.

Remove the upper control arm bolt from the knuckle.


Flex the knuckle back and down and you can just remove the shaft from the
hub.
However, installing it back into place is just pure joy. It will take two
people, one to flex the knuckle/hub assembly and one to squeeze the shaft
into the knuckle hub after shaft is in the diff.
I would say it would be just as fast to remove the lower control arm to
knuckle bolt and pull the knuckle out of the way and it might save some
time.


Besides the required wrenches/sockets, etc., you will need one long pry
bar, plenty of beer

Now, let me throw this out. If the front diff is damaged, why not remove the front prop shaft, (eight bolts; four front/four rear), and drive and some good strong duct tape. Worse that could happen is the ring gear is shaved completely, or the vehicle will not move. I mean, drive at a very slow speed. Prop shaft would have to be removed to prevent damage to the T/case, but who would care about more damage to the diff. Yes, an axle might get damaged, but I’m not sure if I would not take the chance.