Morning from snowy NJ. New to the forum and happy to find this place. I hope I'm posting in the right spot.

I've had an H3 since 2007 now and this is the first time I've had this issue, started 2 nights ago driving in the blizzard. Issue compounded and now seems to be permanent.

In 4 hi I get no power to the front tires and only one back tire spins without traction on snow.

In 4 lock after going into reverse and then forward the Traction control system begins to work then I get an ASR off notification on the dash. I get some pull from the fronts only before the ASR notification- this is the same on 4 low.

I'm hoping its not a transfer case issue- front drive shaft seems happy and no puddles of oil under the truck.

Is there a sensor that if bad could cause these symptoms??????

Thanks

Kindest Regards

JP

 

OK spent a little time researching the BW transfer case in the H3 and have some new input.

Currently 4 hi is useless, like a true neutral the truck rolls down the driveway little clunking noise from the general t/c area under the truck.

4 lock is useless until the transmission is cycled from neutral to reverse and then drives normal except only power to the rear wheels

4 low same symptoms just a different gear ratio.

Sounds like a transfer case issue, feels like a transfer case issue. Anyone had symptoms like this??? Little plastic fork screwing me up????

Still under 100k powertrain warranty?????

2007 with 60K one owner, bought my lease out when they discontinued the truck.

Any help would be great,,,, thanks

 

sounds like the chain is gone,,or something in that area. open it up huh?

the front and rear are always driven,,locked or unlocked

 

I had an 07 H3. When I took it in for an oil change back in 08, they told me they had to take the trannie out and replace some forks. I told them there wasn't any problem and they said it would be covered under warrenty and not to worry about it. The guy said the early 07's had plastic ones that were breaking. I never heard of a recall but he said that some people were bringing them in with this problem and let's fix it before it is a problem. I figured they were just bilking GMC for bucks. Since it was free I let them do it.

 

Sent her off to the dealer for repair, will let you all know the results. Maybe it helps someone down the road.

 

Sounds like a blown up t-case.

 

Hi-Lo Shift fork or the lock up mode shift fork. Older models had plastic forks newer models have metal. Not sure when BW changed designs, but pretty sure it was sometime in late 07 or for 08 models. Could be something else, but that is one of the symptoms of a blown fork.

 

gotta be the chain,, the front is never driven.

in hi open the torque split differential sees no load on the front gear and so, gives zero torque to the rear,,hence, neutral as he said. no rear drive.

in lock hi or lo the back is driven direct but the front is still unhooked,,,no chain.

if it were a fork it would not go hi/lo,or open/lock and it does both.

although there has been talk of a lock mode problem needing to shift to rev to get out of lock,ill stick with my "guess"

 

He does state than eventual front traction is present after going into reverse, but then goes away. If the chain was broken, it would never have any front traction. That's why I would guess the fork.

If the chain was broken, there would be nothing all the time. It could be the planetary differential which splits the power front/rear (40/60 until locked up). But, I believe if the high/low range shift fork is broken or not moving correctly, it will not engage the high/low range sleeve. If the sleeve does not move it will not engage the input shaft to the mainshaft and no power will be delivered to the planetary diff.

Going into reverse might shake it loose.


In all reality, it could be many different items. The chain could be stretched and slipping but that would cause a lot of ratcheting noise. Heck, I might even suspect the encoder motor and this could be proven easily by just removing it and doing it manually.

I will agree, continuing to drive it like it is will eventually affect many parts, not just the chain or the forks (which are likely shot).

We really can't tell until the t/case is disassembled and the culprit is found. At which time, the forks need to be replaced with the service parts (which are metal) and all other parts need to be closely inspected or replaced. The chain should be replaced regardless.

But if it is an 07 and under 100K it should be a dealer problem

 

I have seen this alot, what happens transmission fluid does get nasty and does burn up a tiny amount thus then not having enough fluid in the transfer case. I did a fluid change and I used the service manual I bought, it was like a brand new vehicle after changing it.