You must all be looking to destroy your transfer case. 4wd high or low lock on dry asphalt is a big NO. The Borg Warner transfer case is a chain drive unit and you will stretch and maybe even break the chain trying to turn on dry asphalt in lock. This is a fulltime 4wd system. Normal driving will not be affected when in 4wd high unlocked. These "experiments" and "testing" you have been doing is going to ruin the t-case. Driving at 60 mph in high lock on the highway is simply retarded. Any type of turn or imbalance in the tire pressure will result in severe binding within the t-case. Also, you DO NOT need to engage and disengage the lock mode to lubricate the t-case. The t-case itself is internally lubed with ATF and an oil pump. The oil pump is driven by the output shaft and constantly lubricates the internals of the t-case. 4wd lock should be limited to off-road, snow covered roads, and mud. It has no place on dry pavement. You will also accelerate front end wear, specifically cv joints and possible axle shaft breakage.

 

The H3 is described by Hummer as full-time 4WD. Its either in 4WD high range or low range. It's never 2WD. However, as long as the center diff is open, there are conditions in which the H3 will act like 2WD. Anything that causes the front and rear axles to turn at significantly different speeds would probably do it (e.g., wheel spin on glare ice). I believe its technically AWD unless the center diff is locked.

I think the only thing you do when you engage the button for 4-High Locked is to lock the center differential so both axles are driven together. For 2WD/4WD system, there would have to be a slip-sensing coupling, like a viscous or torsen, in the transfer case that would lock if the front and rear drive shafts turned at different rates indicating slippage. My old Montero had a viscous coupling that engaged 4WD if either axles had slip. As far as I know the H3 just has a center diff. I would like to see a diagram and real technical description of the 4WD system to be 100% sure since GM's info on the 4wd system and operation is pretty sketchy. Here's the most "technical" GM description I could find and its pretty meager (italics are mine).

- 4High-range Open, for optimum highway performance and comfort under normal road conditions (Open Center Diff??)

- 4High-range Locked, which allows torque to be transferred to the front or rear wheels as needed (Locked Center Diff??)

- 4Low-range Locked, for severe off-pavement use, such as crawling over large rocks or logs, or deep sand or snow. (Locked Center Diff)

- 4Low-range Locked plus driver-selectable electronic rear differential locked, with the optional 4.03:1 low-range transfer case gearing, providing crawling and climbing power every bit as capable as the legendary H1 and H2. (Locked Center diff plus locked Rear Diff)

- Neutral, for flat-towing the H3.

 

why are you two replying to me? I think I know that using 4 lock is a no no on dry roads.....quote the person you are talking to in your posts...it avoids confusion

 

Like import said, it's normal.

Anytime you have the system locked, and on a high traction surface like asphalt etc, you will feel that. It's just the system binding up a bit do to lack of slippage. When locked, there has to be slippage, either the tires slipping on the surace, or slippage in the system (unwanted) .. something has to give. The day the tires traction doesn't, is usually the day something breaks somewhere else. The binding results in the feeling of the vehicle jerking a bit, or coming to a stop instead of free rolling like it normaly would.

Avoid locking the system on dry roads. If you need to check the system on dry roads, then it's best to stick to straight line travel, and avoid turns, especially sharp, or U turns.

 

Lol...

Sorry.. I could not resist. I must mind my manors and remember that we all owned our first 4x4.

 

and you would be laughing at who, exactly?[&:]

 

Remember.... its ok to laugh. Just never laugh and point.

Brachilius has some good advice. Listen to him, and long live your ride.

 

umm....ok...guess you don't understand what you read very well then I was asking if anyone else felt it while in NORMAL full time 4 wheel drive, not 4 wheel wheel lock because I was feeling a lurch and didn't think it was normal and that my t-case might have been stuck in 4 lock, but if you read the entire post you would know that. This isn't my first time around the block, but judging by your first posts you won't be on the block very long anyway.

 

Lol...