Transfer case issue?

[rich073]

Just signed up and am new here. Just rebuilt 4L60e transmission that was slipping in 3rd and 4th. Had no issues with the transfer case before hand, but when I put the tranny and t case back in and went through the gears it seemed to be locked up and wouldn't move. I put it in reverse and pressed the gas pedal and it pooped, then went into gear and was moving. Put it in drive and only got a grinding noise like t case not engaging. I tried putting the case in neutral and then back in 4 hi and no changes.
I had an 04 silverado do the same thing once while shifting to 4x4. I was able to put it back into 2wd and drove it home. Tried the 4x4 the next day and worked fine with no more issues. I learned that there is a plastic fork and it could be worn. Thinking since h3s are awd maybe the issue was already there but didn't know it until I pulled the transfer case out and perhaps it disengaged and then won't re engage? Any info or similar issues that were solved would be greatly appreciated, and thx in advance.

 

[rich073]

So I'm replying to my own post since I said the transfer case "pooped". It popped into gear actually, or mybe it did take a big poop and decide not to work?

 

[alrock]

The transfer case does come with a plastic fork; replacements are all metal. When you switch modes for the transfer case, especially from low to hi, can you hear or feel it engaging? But even with a worn shift fork it should work up until the time you try and switch modes. I'm sure someone else will have better ideas than me.

And for almost pointless detail clarification, the H3 is full-time 4WD, not AWD.

 

[rich073]

The transfer case does come with a plastic fork; replacements are all metal. When you switch modes for the transfer case, especially from low to hi, can you hear or feel it engaging? But even with a worn shift fork it should work up until the time you try and switch modes. I'm sure someone else will have better ideas than me.

And for almost pointless detail clarification, the H3 is full-time 4WD, not AWD.

Thx for the clarification, and yes, when I switch modes you can hear it trying to engage but forward sounds like a gear skipping or slipping? Like it's not fully engaged. When I put it into neutral mode even reverse sounds the same as forward. Back into 4hi, lock, etc. It engages for reverse but not forward

 

[alrock]

Considering the symptoms, I don’t know if you have many options but to take down the transfer case and tear it open. I also wonder if it’s the transmission rebuild - it wouldn’t be the first rebuild that wasn’t successful. But to prove that point you may need to prove that the transfer case isn’t the issue.

What doesn’t make sense to me is how the transfer case works in reverse but not in forward modes. I’m not a transfer case expert, but I’m pretty sure that the transfer case is ignorant to the direction you are driving. Maybe it’s because something is broken inside, like the chain or a broken piece jamming the gears, and it’s only engaging in reverse, but usually the forward/reverse thing is a transmission.

For the record, I did blow up a transfer case so well that I only got it to move forward after a few forward/reverse changes where I basically ended up jamming the chain into the gears so that things engaged. Not suggesting this is your situation, but it is a situation where the transfer case is the issue.

 

[rich073]

Considering the symptoms, I don’t know if you have many options but to take down the transfer case and tear it open. I also wonder if it’s the transmission rebuild - it wouldn’t be the first rebuild that wasn’t successful. But to prove that may need to prove that the transfer case isn’t the issue.

What doesn’t make sense to me is how the transfer case works in reverse but not in forward modes. I’m not a transfer case expert, but I’m pretty sure that the transfer case is ignorant to the direction you are driving. Maybe it’s because something is broken inside, like the chain or a broken piece jamming the gears, and it’s only engaging in reverse, but usually the forward/reverse thing is a transmission.

For the record, I did blow up a transfer case so well that I only got it to move forward after a few forward/reverse changes where I basically ended up jamming the chain into the gears so that things engaged. Not suggesting this is your situation, but it is a situation where the transfer case is the issue.

Thx for the input, and yeah I was scratching my head. However I'm really thinking the chain was wore and got hung. Think I'll pull it apart and see if the chain broke. I will post with results when I get time to get to it, and thx again

 

[CaseyS]

A missing or sheared front driveshaft would give some of the behavior you are describing. Did you reinstall the front driveshaft?

 

[Happy Hummer]

If it worked b4 hand maybe you missed something on rebuild, install?
Lord knows I've made mistakes lol.

 

[rich073]

Got t case tore down. Had a burnt fork, actually melted through. Broken chain, guess it was wore out so bad that the slack got it hung. Got it all back together and it down the road then noticed it wasn't shifting so I pulled the pan off of the trany to inspect. Found a plug broke on one of the solenoids. The rebuild kit came with a filter and was for a silverado which was the wrong size and when I put the pan on it put pressure on the solenoid and broke the plug. Got it replaced and it is working fine now. After all the headaches I'm glad to be done with this one. And to add to it, the t case some how got sifted while out of the truck. When I put the motor back on the case I had to rotate it to get it to line up. I put the bolts in and when I drove it, it was in 4 lo lock. Took the motor back off, shifted to 4 lo lock to rotate motor, put it back on then shifted to 4 hi and all was fine. Thx for the help

 

[rich073]

Now on to my 79 c10 project restoration. Excited to get this on started. Pulling the engine to rebuild the 350 with 400 forged crank, flat tops, 2.02/ 1.60 upgrade valves with all the good stuff to boot. This is the stuff I like doing; seeing an old 150 hp engine hit 500 hp. Built a 09 LS last year and got 560 hp at the rear wheels on dino!
The hummer tranny build was actually for my brother's humdinger

 

[Happy Hummer]

Thanks for the follow up. it is always appreciated.

 

[Siamak]

New owner of a H3 2007 with 185k miles here and want to share my transfer case experience. So when making a sharp turn usually to park in the drive way the car would not move and I had to back up the car and go back and forth several times to park the car. The car was driving very sluggish and heavy and sometimes I heard a load metal on metal clunk noise when making a sharp turn. I had this problem on-off and sometimes was able to make a sharp turn without problem. Took my car to four different mechanic shops (including a GM dealer) and each of them found something broken and changed it but did not solve the problem. I ended up doing google search and reading the Hummer forums about other H3 owner's experience and found out about the TC plastic shift fork. I took my car to a transmission shop in Mission Viejo and ask them to open and inspect the transfer case (and agreed to pay $400 just to open the TC). Turned out that the jaws of the plastic shift fork are worn and the TC is locked in 4hi/low. There was a lot of debris in the transfer case and the TC oil pump filter was torn which was replaced. The shift fork was replaced by a GM metal fork. The drive shaft was also changed. The improvement in driving is very noticeable. The sharp turns are now without problem and the car seems to drive faster and easier. I think I have been driving for weeks in 4hi/low lock because of the shift fork malfunction.

 

[H3Hummer]

Well it's a GM safe / spend cash job..... well known. I replaced mine with the aluminium one and changed the filter like few of us did. Never had issues. But that used drive shaft has nothing to do with it

 

[alrock]

Siamak, glad you're fixed up and that reading the forum may have helped you out.

 

[ajefferson]

I got a 06 Hummer h3 just recently I noticed it was riding real ruff like almost the shocks has went out but I know that's not the case like every little bump is 1000 times harder than it was the day before as I get going down the road it feels like it's locked in high has trouble turning now the front drive shaft is locked up tight tight.. any ideas?? This is my every day driver and I'm stumped