96' xj sport 4x4 embarrassment

I believe its a command trac (2h-4h-n-4l). I couldn't believe I was getting stuck in ~7inches of snow. Here are the things I noticed as I was trying to pull out of my driveway, while neighbors were probably laughing theirs asses off.

1. None of my "4x4 engaged" light comes on.
2. two to three wheels doesn't turn while others spin with no resistence, in 4H and 4L.
3. I try to get a moving start with all 4wheels spinning, but 2to3 of the wheels eventually stop spinning.
4. My 2wheel drive shift lever as no trouble going up and down the range.

It looks like I am shifting into 4wd mode fine but its just not getting enough torque to all the wheels. I want to think it might be the vacuum line or the 4wd linkage, but I just don't see how that would cause this problem.

1. Don't worry about your vacuum--you don't have a D30 CAD axle, no vacuum engagement.

2. NP/NV 231 transfer case.

3. A differential, which you have in both axles, is doing its job when one tire is spinning it keeps providing power to the spinning wheel and the other wheel stops getting power. Use of a "locker", auto/LSD/Lincoln/mini-spool/command, will keep both wheels turning on a single axle.

4. You need to get some traction, 4wd is useless without traction. Chains, studded tires, snow tires, whatever it takes to get a bite on the road surface.

5. The more throttle you give it, the worse it gets. Try being a bit gentler.

6. Even in 4wd, without traction, you will slip and slide into things. Slow down and be easy on the accelerator, or you are going to get hurt.

Tires and driver-ability make a huge difference in the snow.

My stock XJ's have no issues going in as much as a couple of feet of snow.

Some tires are better than others, search and you will get plenty of testimonies. Also, try "feathering" the brakes with your left foot as the Jeep is spinning with light throttle. This will create drag against the wheel that is spinning and split some of the power to the wheel that is not. This is very similar to how ESP/traction control works on newer vehicles.

Try NO throttle, just idling in 1st (or R) and very light braking to hold speed DOWN for control. AVOID any wheel spin.

"Creeping-along" at 1-2 mph will often get thru bad spots in an emergency. Nice skill to have. (practice 2w & 4 wheel drive in a safe area)

Of course, if there is traffic find a safe place and PARK IT, you have no control over the other 'drivers'!!!

4WD doesn't mean all four wheels are under power all the time, it means that both driveshafts get power all the time, and the differentials on the axles will distribute that power to whatever wheels are able to take it. With open diffs and slippery surfaces this means that one wheel on each axle is going to get the power. If the wheels are able to get traction and spin at the same speed (ie, going absolutely straight with all tires exactly the same diameter) then torque will be distributed and you'll get real 4WD. If you want real 4WD all the time you need to lock the differentials somehow.

Just few more additional information. I was just trying to pull out of the driveway. I tried applying light braking to increase torque to non-slipping wheel. This just ends up slowing down the spinning wheel and eventually all wheels stop spinning. I leave it at idle and its just free spinning on the wheels that are unstuck. I have some knowledge how differentials and 4wd systems work, I just can't believe how little torque my axle's are getting, at 4low setting. My jeep has 4.5" rubicon express superlift, np231, old man emu, 31" BFG with 90% thread. I don't think tires and clearance are issues for a only 7" of snow.

By design, I know its an even 50/50 split for each side on open differentials. You want to control the rpm and feathering brakes to maximize and fool the system but the problem is that 50% of little torque is..ummm, too little. Those non-spinning wheels should definitely be spinning on 4-low setting, its only 7" of snow.

I don't think there is a problem with 4-hi, I think there is something definitely not right with the 4-low.

Although getting lockers might help with this specific scenerio, its not a good idea to have them as a daily commuter. Not really worth getting the ARB system because of cost. And other lockers would do more harm than good for slippery conditions. This jeep is my daily commuter.


For guys running factory open diffentials, what are your wheels doing in 4low when you are stuck in mud or snow? Are all 4wheels spinning?

4-low and 4-high are exactly the same except for gearing

It is never 50/50 split in open differentials, unless the traction is exactly the same for both wheels. If one wheel has less traction, it will get all the torque, and the one with better traction will simply sit there. This is why people get lockers.

It's very rare to get all four wheels spinning with open diffs, even on glare ice. The one that breaks loose first will take all the torque and spin, and the other one will just sit there.

As ehall points out, there is no difference in differential action in 4 low, except you'll set the wheels spinning faster because you're getting more torque. If you want to get underway gracefully with open diffs, you must reduce torque so that wheels do not spin. Don't confuse torque with traction. Start as gently as you can in as high a gear as you can get.

Light braking can sometimes trick the differential into letting the wheel with the better traction take some of the torque, but it usually won't work unless you decouple the brakes left to right. That's why tractors have two brake pedals - if your right wheel spins, brake the right alone, and it will start sending torque to the left. Some offroaders accomplish the same thing by using the parking brake cables independently, but any benefit from dragging the service brake will be slim to none.

You are getting torque to the wheels, there is nothing wrong with the Jeep.

You don't have traction, let me repeat that--you don't have traction. By the way, did I mention the lack of traction?

NHRA top-alcohol dragsters have plenty of torque, but in your situation they wouldn't be moving due to the lack of traction.

How are your tires inflated? You could try lowering the pressure some, or chains, or studs, or snow tires. Traction--word.

chris9911 said:

I don't think there is a problem with 4-hi, I think there is something definitely not right with the 4-low.

Although getting lockers might help with this specific scenerio, its not a good idea to have them as a daily commuter. Not really worth getting the ARB system because of cost. And other lockers would do more harm than good for slippery conditions. This jeep is my daily commuter.


For guys running factory open diffentials, what are your wheels doing in 4low when you are stuck in mud or snow? Are all 4wheels spinning?

Click to expand...

Why not ??

I have a locker in the rear of my daily driver, and it works just fine.

Slippery conditions or not.....works better then the stock open diff I had before that is for sure, but if you get on it too hard, in slippery conditions, you will spin at a minimum 3 of the 4 tires (usually all 4).

Been driving it for 4 yrs now this way, and still on the same set of tires.....still over 1/2 the tread left as well.

As has been said, with open diffs, even in 4low, if the traction on both sides of the axles isn't the same, you WILL NOT spin all 4 tires

there is nothing wrong with your jeep. Joe, Matthew, and ehall are all giving you correct info. you need at least a limited slip diff. to split any torque at all.

Are your BFG's mud terrains or all-terrrains? I have open diffs in my XJ, but I'm running dedicated snow tires. We got 8 inches of snow the other night and went out and ran some trails and I ran most of them in 2WD without issues. Careful throttle control and the right tire for the situation make a big difference.

My stock 2000 with street tires gets through 7+ inches. And with the stock street tires (maybe 75% tread), I can out acceletate all of the new AWD Sport Utes with their 300hp motors and big tires. The XJ just digs in and goes.

Just be glad you don't have the full time 4WD. The open dif in the transfer case lets even one tire spin. At least with part time 4WD at least two tires have to spin befroe any will spin.

Like Joe said, you are confusing spinning with traction. By the way, the whole key to moving in snow or mud is MOMEMTUM. Rock back and forth to try to gain movement. Once you get even a little movement fore and aft, you should be able to get some momentum going,