Why did I not have front wheels spinning?

[tomp]

I got high-centered this morning. Was in low-locked and only the back wheels were spinning.

I was going uphill and high-centered as the front wheels went over the top. There was plenty of force down on the front suspension and I could have really benefitted if the fronts were spinning as well. Why does this happen?

[drmiles]

Transfer case in 4 Hi, not 4 locked. Locked forces the front to spin with the rear. 4 Hi directs more power to the rear 60% (i think).

[f5fstop]

If you are in four wheel HI mode, the traction assist system applies the brakes to the spinning tires to allow all engine power to the other wheels. Spinning tires give no traction.

[Dug]

DO you know if the fourwheel drive was working before you noticed the front wheels were not spinning?
When you was in low lock, are you sure the tire on the opposite side of what you could see was not turning?
Trying to help narrow down the possibillities.

[tomp]

At part throttle, nothing was spinning. Then, when applying more throttle to make it over the top, the rear would break loose and spin. Fronts never would move while rear was spinning as both fronts were on the ground and I was sitting still.

Only way to make it over was to reverse and build up some forward momentum.

Also tried slightly mashing the brake during throttling and that did not do anything

[tomp]

I will have to try this move again next time I'm out. However, it did happen several times over this weekend.

Any idea what keywords I could search on to bring up those threads that show each mode? IE, TC, TC2, 4x4 hi, 4x4 low, and 4x4 low-lock?

[timgco]

I will have to try this move again next time I'm out. However, it did happen several times over this weekend.

Any idea what keywords I could search on to bring up those threads that show each mode? IE, TC, TC2, 4x4 hi, 4x4 low, and 4x4 low-lock?

i don't want you to think I'm implying you don't know what you are doing, but are you 100% positive it was in 4lo locked. I have seen people push the button while moving and the light flashes but does not engage.

It's possible the light can be solid also and the T Case is not engaging. I've seen this on two trucks to date.

Did you BTM while in 4 LO Locked? If so, were you turning the stering wheel back and forth? Sometime this will give the truck a slightly different angle since it had most weight on the front and cause one of the front wheels to spin.

you may want to follow up with the dealer if you have one close by to check out your T case and to see that everything is engaging properly.

Good luck,
Tim.

[tomp]

Tim, 110% sure it was 4-wheel low-locked. There is no mistaking it. Changed into that mode in neutral while stopped and did this each time before encountering the uphill climb. Each time it did the same thing.

[ShortBus]

My front driver tire tore into the wiring loom that runs on the frame at the back of the tire. This caused some electircal problems that included the transfer case not getting the signal to engage. If you have been doing any heavy articulation, I would check it out. If this is the problem, don't be afraid to tape'em back together. The dealer charged me $100 bucks to do mine and it looks like crap.

[Hummie2]

Sounds like a serious T-case problem. Could be a broken lockup shiftfork not letting the T-case go into lock mode. The shift motor turns the shifter cam and the encoder shows that it shifted, but nothing happen inside the T-case to shift the gears. Was the front driveshaft turning when you noticed the front wheels weren't spinning?

[tomp]

Not a wireloom problem

Hummie2, I need to check the front shaft next time I am out. More than likely it was not spinning, but still good idea;)

[Dug]

Since your 110% positive its in low lock (as in you could feel it was in low gear when driving ahead. ) It sounds like there could be a transfer case problem. Do you know if you have four wheel drive in Hi range?

[tomp]

I will try and take some time this week to raise all four off the ground and go through each mode to determine if I get wheel spin.

[timgco]

I will try and take some time this week to raise all four off the ground and go through each mode to determine if I get wheel spin.

Are you still uner warranty? How close is the dealer? You may want them to look at it. THey can hook their techh II up to check for issues.

Also, if you have a Hypertech Programmer, plug it in and see if you get any codes.

[Dug]

I will try and take some time this week to raise all four off the ground and go through each mode to determine if I get wheel spin.

tomp - a quicker way than jacking all fours up in the air to find out if your 4wd is working. Is to go out in some dirt , put it in reverse and floor it. You will now if the four wheel drive is working. :D

[tomp]

Wanted to clarify to everyone, that I did have the rear e-locker enabled during that time. Not sure if this makes any difference to what I was experiencing or not, but did want to bring it up just in case.

[Hummie2]

Tom, here is what you do:

1)If you have a floor jack (trolley jack) go out in the driveway and raise both rear wheel off the ground slightly. (about an inch or two)

2) get in and start the truck, shift to 4lowlock, apply the brakes lightly (just enough to illuminate the brakelights. This will disable Trac Control)

3) shift the transmission into gear and see if you can move the truck slowly with the rear wheels off the ground.

Does the truck move? If yes it went in lock ok. If no, does the front driveshaft spin? If the front driveshaft doesn't turn then the T-case isn't locked (all power going to rear axle only). If the driveshaft does turn and the halfshafts & wheels don't, then the problem lies in the frontend. (broken axleshaft, spidergear,etc.)

Being able to lock the rear E-Locker shows that the T-case motor encoder signaled T-case shift module that the shift to 4lowlock was completed, but did gears actually move to 4lowlock inside the T-case? (broken shiftfork)

[SUT NEIL]

Don't forget to have your trolley jack wheels in line with your vehicle wheels, or you'll just pull the truck off the trolley jack.


X2! Good point!

[tomp]

H2, this was a very good suggestion and made very good sense! It sounded as the quickest thing to test it as well.

I just finished dragging the jack up and down the driveway, so it appears that's it's working as designed.

I am still not sure why the front couldn't assist in getting me over the hill. Does the TC divide up the power from front to rear?

[Hummie2]

Does the TC divide up the power from front to rear?

Yes, 50-50 in 4hilock & 4lolock.

[tomp]

It was definitely in low gear and the rear axle was surely locked up.

It could have acted up that day though, as after I shifted back into regular mode - it was binding at the local gas station like it thought it was still locked.

Thanks for all the help you provide here Phil. You've definitely sold a Locker, just gotta get the wife into it. If you ever thinks its strange all these women are placing orders, don't worry - it's just our wives!

[Dug]

Tomp , i'm wondering if your last post just pin pointed your problem.
Sounds like your shift motor is slow or T/C needs oil ???? or something is making it shift slow. You said it was binding and hadnt unlocked after shifting out for a little while when you were going to the gas station. Probably it is shifting in slow also , maybe thats why it wasnt locked in when in question , because you had just shifted in at the bottom of the hill and it hadnt engaged yet by the top of the hill even though it was in low range maybe it wasnt fully locked yet. Just guessing. :popcorn:

[ROX]

If you ever thinks its strange all these women are placing orders, don't worry - it's just H2 Rocks, Hummbebe, Hi Hummer, Co-pilot, H2 Bully, jfox, .....!FXT!

[tomp]

Tomp , i'm wondering if your last post just pin pointed your problem.
Sounds like your shift motor is slow or T/C needs oil ???? or something is making it shift slow. You said it was binding and hadnt unlocked after shifting out for a little while when you were going to the gas station. Probably it is shifting in slow also , maybe thats why it wasnt locked in when in question , because you had just shifted in at the bottom of the hill and it hadnt engaged yet by the top of the hill even though it was in low range maybe it wasnt fully locked yet. Just guessing. :popcorn:

Now you got me wanting to check it because I changed the fluid over to mobil1 ATF about 2 months ago. I remember that foam gasket sealer was protruding out at the bottom of the TC. I didn't think this would cause a leak, as there should be a real gasket in there as well - at least there should be.

Can the TC change into lower gearing without locking front?

[tomp]

FXT!

Sorry babe, i wasn't trying to imply there wasn't any wheeling-women that were not ordering;)

[Boar-Ral]

It is possible that for whatever reason, the vehicle thought it was getting more traction from the rear wheels. You could attempt to use TC2 next time and see if you get any wheel spin from the front. That's all I can think of.

[Hummie2]

You may be getting some wear in the shift detent cams or between the encoder motor and the shaft that turns the cams. That would cause the shift forks not to reach their full range of travel. The encoder motor reaches it's proper position and sends the signal to indicate the shift was complete, but wear in the cams,forks,shaft etc. may cause some lost motion in the shifting mechanism causing the lock sleeve not to be fully locked or unlocked completely.

If the problem happen again its time to open the t-case up and see what's going on in there.

[Hummie2]

Can the TC change into lower gearing without locking front?

It could be possible. There are 2 shift forks, one for hi/lo range and one for lockup.