Hubs won't lock and transmission problems

Ain · #1 01-09-2005, 01:32 AM

Looking to see if anyone has some suggestions while I'm stuck in the snow up in Tahoe, 60 miles from a Hummer dealer who won't be open until Monday...

Tried pulling out in the snow this morning with the H2 and the was basically getting no traction. Finally got the thing moving with a push and found that trying to switch from 4HI/lock to 4HI/unlock results in a lot of mechanical noise and then loses all power.

Shifting back to 4HI/lock stops all the grinding noise, but it appears that power is only going to the rear tires. You can see the front wheel shafts rotating, but the hubs don't appear to be locking. Shifting to 4LO seems to have the same result.

Anyone have a suggestion for trying to get the hubs to lock in the front? I've abandoned the H2 for the night, but would like to try to get it moving in the morning and it won't make it too far in the current conditions on 2 wheel drive.

- Ain

Ain · #2 01-09-2005, 01:32 AM

Looking to see if anyone has some suggestions while I'm stuck in the snow up in Tahoe, 60 miles from a Hummer dealer who won't be open until Monday...

Tried pulling out in the snow this morning with the H2 and the was basically getting no traction. Finally got the thing moving with a push and found that trying to switch from 4HI/lock to 4HI/unlock results in a lot of mechanical noise and then loses all power.

Shifting back to 4HI/lock stops all the grinding noise, but it appears that power is only going to the rear tires. You can see the front wheel shafts rotating, but the hubs don't appear to be locking. Shifting to 4LO seems to have the same result.

Anyone have a suggestion for trying to get the hubs to lock in the front? I've abandoned the H2 for the night, but would like to try to get it moving in the morning and it won't make it too far in the current conditions on 2 wheel drive.

- Ain

Ain · #3 01-09-2005, 01:32 AM

Looking to see if anyone has some suggestions while I'm stuck in the snow up in Tahoe, 60 miles from a Hummer dealer who won't be open until Monday...

Tried pulling out in the snow this morning with the H2 and the was basically getting no traction. Finally got the thing moving with a push and found that trying to switch from 4HI/lock to 4HI/unlock results in a lot of mechanical noise and then loses all power.

Shifting back to 4HI/lock stops all the grinding noise, but it appears that power is only going to the rear tires. You can see the front wheel shafts rotating, but the hubs don't appear to be locking. Shifting to 4LO seems to have the same result.

Anyone have a suggestion for trying to get the hubs to lock in the front? I've abandoned the H2 for the night, but would like to try to get it moving in the morning and it won't make it too far in the current conditions on 2 wheel drive.

- Ain

Ain · #5 01-09-2005, 01:48 AM

Nope, it's in a snow covered parking lot right now. I actually had to put it in 4LO and lock the axle in the morning to back it up, but with a bit of ice, this only allows you to spin both rear tires instead of one at a time.

Without the fronts locking up, it's basically a 2WD. Even in 4LO and locked, the rears spin too easily since there's not as much weight back there, and without any pull from the front it's going to be tough.

- Ain

Hummie2 · #7 01-09-2005, 01:10 PM

Ain...

There are no locking hubs on a H2. If you are hearing grinding gear noises and the front end isn't pulling you have some serious issues either with the transfercase or front axle.
Sounds like its time for a rollback wrecker and a ride to the shop. What were you doing when the problem started?

DRTYFN · #8 01-09-2005, 01:46 PM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by Hummie2:
What were you doing when the problem started? <HR></BLOCKQUOTE>

Most likely doing cookies and he hit a bare patch and snapped something. Bad boy.

PARAGON · #9 01-09-2005, 01:51 PM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by Ain:
Looking to see if anyone has some suggestions while I'm stuck in the snow up in Tahoe, 60 miles from a Hummer dealer who won't be open until Monday...

Tried pulling out in the snow this morning with the H2 and the was basically getting no traction. Finally got the thing moving with a push and found that trying to switch from 4HI/lock to 4HI/unlock results in a lot of mechanical noise and then loses all power.

Shifting back to 4HI/lock stops all the grinding noise, but it appears that power is only going to the rear tires. You can see the front wheel shafts rotating, but the hubs don't appear to be locking. Shifting to 4LO seems to have the same result.

Anyone have a suggestion for trying to get the hubs to lock in the front? I've abandoned the H2 for the night, but would like to try to get it moving in the morning and it won't make it too far in the current conditions on 2 wheel drive.

- Ain <HR></BLOCKQUOTE>The H2 is full time 4 wheel drive, there are no locking/unlocking hubs. There is some normal mechanical noise when switching from high to low as the transfer case switches. The difference between 4hi lock and unlock is that locked simply means a true 50/50 power split front to rear but even in unlock there is power to the front, it's just not locked at 50/50.

Do the words Traction Control come up on the DIC when you are spinning the tires? Where are you seeing shafts turning?

Ain · #10 01-10-2005, 12:18 AM

4HI (unlocked) won't engage at all. Just lots of grinding and mechanical noise. 4HI/LO LOCK will engage, but only the rear wheels get any power.

Even though te H2 is a full time 4WD, I'm guessing there's a different shaft for the 4HI mode that adjusts the power split, and this is busted. I'd bet all the problems are in the front differential, but there's obviously a secondary problem preventing the hubs from turning in 4HI/LO locked??

"Traction Control" will come up on the DIC when the rears spin as well. Otherwise, all the lights and indicators act if nothing is wrong. The loud grinding noises are the only "service" indicator.

I'd bet something broke in the front diff long before I switched to 4HI LOCK the other day once it hit the snow. Since the lights lit up normally, I was probably driving around with the rear wheels only until it got heavy and realized there was no front traction.

Hummer Roadside Assistance was unwilling to pick up the vehicle since it was in the snow (claimed none of their service providers were equipped to do so). Since the weather wasn't expected to clear, I got a break and managed to get it out in 2WD before the next batch of snow came in and dropped it at a dealer myself this afternoon.

I should find out the problem tomorrow and will post a follow up.

- Ain

Ain · #11 01-10-2005, 12:20 AM

Forgot...the front half-shafts can be seen spinning by looking behind the front wheel if it's turned slightly.

This was noticed while it was stuck and the rears were spinning in place. I've also been told there is a control in the hubs for the power split so this wasn't working either.

- Ain

ROX · #12 01-10-2005, 12:52 AM

If it isn't running in 4hi, (full time 4wd), then it's definitely got something wrong with it. Good luck.

DennisAJC · #13 01-10-2005, 01:26 AM

Check to see if the batteries in the remote are fresh.

If not, it could be the batteries in the RC itself. Good luck kiddo.

ROX · #14 01-10-2005, 02:09 PM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by DennisAJC:
Check to see if the batteries in the remote are fresh.

If not, it could be the batteries in the RC itself. Good luck kiddo. <HR></BLOCKQUOTE>

That's really funny!!!! I hope Ain finds a little humor in it.

Kevin B · #15 01-10-2005, 07:53 PM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Even though te H2 is a full time 4WD, I'm guessing there's a different shaft for the 4HI mode that adjusts the power split, and this is busted. <HR></BLOCKQUOTE>

Yetti · #16 01-10-2005, 11:30 PM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR> Forgot...the front half-shafts can be seen spinning by looking behind the front wheel if it's turned slightly. <HR></BLOCKQUOTE>

This is not normal!
you would have had to have sheard a spline shaft or twisted the shaft till it popped a clip and then backed out of the CV Joint at the wheel. the CV is what holds the hub compressed, its splined through the center of the hub and bolted solid. the noise you were hearing while shifting was from not putting it neutral and waiting for the gears to shift in gently. I have busted transfer cases by being in a rush.
as for the HI/Loc function, that is done inside the transfer case no where else. there is a planetary inside that "gives" between the front and rear axles, it locks that & then makes the power split 50/50. sounds like it was spinning a wheel and then grabbed pavement snaping a shaft off at the hub.

Kevin B · #17 01-10-2005, 11:45 PM

Yetti, your hypothesis makes since. If the trans/transfer was allowed to "freewheel" through the front axle shaft the Hi/Low functions would be very hard to engage due to them moving. That would also explain the difference in the locked position, if im reading the problem right..

Does that make since?? MMMMMMMMMMMMMMMMMMM Could Be?

unaslob · #18 01-11-2005, 12:38 AM

you need to hit that onstar button and get a flatbed to come pick you up... any thing else will probably only cause further damage.

unaslob

Ain · #19 01-11-2005, 06:38 AM

Yetti - good info on the hub assembly. If the shafts are bolted to the hubs, it definitely busted in the CV joint.

On the plus side, this might mean that the front diff might not be trashed, and the engagement problem is a side effect.

I had dropped at a dealer yesterday, so I should have a full diagnosis by Wednesday.

- Ain

Ain · #20 01-14-2005, 05:01 AM

Initial report from the dealer is that the right side front drive shaft snapped at the connection to the wheel hub.

They also said something doesn't appear right with the front differential, but they need to take it apart to see what's wrong with it.

Since the right shaft could be seen turning, I'm guessing the front diff was treating things like the front left was stuck and diverting power to the right since it was just spinning freely.

Still unsure why the axle snapped since the conditions were not exactly extreme...just snow covered roads.

On the plus side, the dealer said everything is being covered by the warranty.

- Ain

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