Four Wheel Drive in a Jeep

My guess is if one tire is in the air, then the Jeep is resting on the frame/underbody and not the tires. In other words, there's no pressure on the tires and all of them will spin. Only way you're going to come off is to shovel out under the car or a winch/tow truck.

Best of luck,

Jim Clark-Dawe

I agree with JCD.

Have the thing get stuck in a snow bank up top the windows. It is reasonable that one wheel might spin that way. Putting it four wheel drive wil put power to all four wheels, and the thing should come out, unless the driver is a moron and revs the engine so the tires spin and ice forms under them. That's how to leave a car in a sonbank.

Define "up in the air". If it's a couple of inches off the ground, you can put a board or something similar under the other tires (sometimes even cardboard will work) and use something a bit thicker to make up the difference with the elevated one. If it's a foot or more off the ground, I hope you have a cell signal and a friend who doesn't mind getting out in the snow to pull you out.

As important as four wheel drive in these situations (perhaps more important) is the differential lock. Normally it is turned off, and the mechanism for turning it on varies from one vehicle to another. When it is on, each axle works like a solid rod, when it's off, each wheel spins independently and all of the torque will go to the wheel that's spinning freely.

Knowing the year & model would help...

If you're not familiar with the tech, these sites might help...

http://www.motortrend.com/features/consumer/1105_4wd_vs_awd/viewall.html

http://en.wikipedia.org/wiki/Jeep_four-wheel-drive_systems

http://www.awdwiki.com/en/jeep/

I would say that your best bet is to have her get high centered on the snow. None of the tires necessarily need to be off the ground in order for them to lose traction. I agree with ironmikezero though, in that knowing the year and model makes a difference. We currently have a Jeep Rubicon. It has differential locks in addition to the four wheel drive. The differential lock basically locks the two rear or two front tires together so that they have to spin at the same time.

A vehicle with a limited slip will automatically put power to the tire that has traction. So if there is one tire in the air, that tire will only get a small percentage of the power, and the tires on the ground will get the rest. However, if it's running an open differential, the tire that doesn't have any traction will get all of the power leaving it spinning and your MC stuck.

My husband and I took my old Jeep Cherokee up a trail one day. We were trying to get through an avalanche basin and ended up with all four tires sunk down into the snow. We couldn't get traction. All tires were on the ground, but they were all spinning. We finally ended up with him rocking the Jeep back and forth while I tried to reverse it in order to get it out.

High centering on the bank is the way to go. At best, she'd need someone to push, at worst, a tow. I've done this with several 4WD vehicles in snow, mud, sand and swamp, including a '94 Cherokee, '86 Wagoneer, '72 Jeepster Commando and a 2007 Wrangler. Though I was prepared for most (spun a 4WD Subaru into the snow avoiding a squirrel and had to be pushed out), without a winch she would need help.

Jeff