Got an 07 Hummer H3 in the shop. Haven't seen one in awhile but this one has all the usual issues - front axle support bushing shot, bad coil, etc. The big issues being dealt with are the P0604 5V reference issue which I have fixed but the one last issues is when turning into a parking space it just feels like you are in 4WD LOCK. The truck slows down like the brakes are on and the front tires hop - just like a part time 4WD would do on solid pavement. This is an always 4WD setup with only 4HI, 4HI LOCK, Neutral and 4LO ranges. I checked every underneath. I changed front axle fluid and transfer case fluids and still does it. Research shows shift fork issues inside the transfer case as common. I can hear the vehicle encoder motor shifting and it will go into Neutral and all the ranges. I was considering throwing a new encoder/shift motor on it but I don't think that is it. Anybody on here have this experience with an H3 or any ideas before I pull the Transfer case and start looking inside? I think it might have the improved aluminum shift fork based on build date but have to look. There were issues with the earlier plastic fork. Thanks All!
07 Hummer H3 steering issue
- Thread starter GMBoy
- Start date
Again, our old '05 Yukon used to do something similar if you whipped into a parking spot on dry pavement, and my parents' '06 Silverado just did it to me at an intersection. Both NP246, though
So if there's a 4hi LOCK then just plain old 4hi must be essentially 4hi Auto? Are you sure the front d/s is disengaging in 4hi Auto?
Basically I'm asking if it's mechanically stuck OR is it doing what it thinks it's supposed to do and engaging the front output when it THINKS wheel slip is occurring?
Does this case use a clutch basket like the 246?
So if there's a 4hi LOCK then just plain old 4hi must be essentially 4hi Auto? Are you sure the front d/s is disengaging in 4hi Auto?
Basically I'm asking if it's mechanically stuck OR is it doing what it thinks it's supposed to do and engaging the front output when it THINKS wheel slip is occurring?
Does this case use a clutch basket like the 246?
get a transfer case from an old Chevy truck that has a real shifter and no motor. cut a hole in the floor for the shifter. get rid of the 4x4 computer and wire in a switch for the front axle disconnect (if equipped) do some research, there might be a write up on how exactly to do this. if it's not your car then ask the owner if they want it fixed
It feels like this is a standard repair scenario and not a custom fab undertaking. I doubt the customer would be receptive to heavy mods and to do it right would be $$$$
that's true, however some old gm trucks still have a plate in the floor and the transfer case bolts right up. it would be $$$ but I wouldn't think it would be much more than a normal transfer case replacement if the shop knows what they're doing and will give a fair price. as with any modification, there's some risk of messing stuff up and not being able to go back to stock configuration.
the customer probably doesn't want their fancy awd changed for an old school 4x4 system anyway
the customer probably doesn't want their fancy awd changed for an old school 4x4 system anyway
Customer car - they want it stock.
It's not disengaging as it should. Appears to be an internal Tcase issue as it does shift from 4 to 4Lock and back and even into 4LO and N. It appears stuck mechanically and I should have mentioned that draining the fluid was nasty dirty and like black water. I drained and filled it twice with Valvoline T-case fluid. I think its toast.
It occurred to me it may also just have a mechanical differential in there for FT 4wd, in which case you're probably right.
If it uses a clutch basket like the 246 it's almost impossible for it to get jammed in 4wd because it has to lever (literally) the clutch packs and mash them together. The second pressure is released the clutches start to slip on each other. The shift motor is responsible for the "mashing" and just holds it there, but there's no other mechanical lock for the internal lever arm.
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