Just bought a 2011 4x4 Dakota and when I put it in 4x4 high doesn't seem to be working. I spin alot. Tires are ok, however tonight put it in 4 lo and it backed right up off the ice like it was summer. Light comes on seems to be working any idea what this could be?

 

 

I drove the truck in 4 hi and slide all over the road. Got stuck on flat pavement with a little ice couldn't move, light turned. Put it in 4 lo and the truck didn't even hesitate to move from the ice. Wondering if this would be a transfer case or encoder motor issue?

 

That's how open differentials work - when one tire slips, even in 4x4, the same torque that caused even one tire to spin is sent to the rest of the tires. Hence if you were to gun it on ice, even in 4x4, you might not get anywhere.

4x4 doesn't make you impervious to ice. Requires patience and time to get out of that. 4Lo just makes the wheels rotate a bit faster at idle, which probably helped get you out.

 

Not quite. With open diffs, the tires with the LEAST traction get all the power. One in front, and one in the back. I have been stuck in situations where I have three tires on ice, and one in snow, and could not move. All power was going to the tires that were slipping. (no posi rear on that truck, not that it would have mattered.....)

In 4 low, the tires will rotate SLOWER at idle. it is low range, after all. I don't know what t-case the OP has.... but, some of them actually have open 'differentials' incorporated into the drive system, and only lock when in 4 lo...... Think is, in 4 lo, since it is geared lower, you aren't as likely to spin the tires when easing into the gas. So, you get traction, instead of moving a bit, then slipping.

 

Lol time to hit the books again

 

Turn on your 4X4, start moving forward slowly, then turn your wheels to the left or right, if it "fights" you, the 4X4 is working. By "fights" I mean if it resists you turning, maybe makes a groaning sound, then it's on. That's what mine does on my Ford. It's been a few years since I've had the Dakota out in the snow, can't remember if it did the same thing or not...but I think it did.

 

An open differential always sends the same amount of torque to both wheels, but since energy always takes the path of least resistance that torque is determined by what ever wheel has the least traction, that is why if one wheel is on a slick surface it will spin but the other wheel won't, even though they are both getting the same amount of torque.

 

No, it doesn't. The wheel with the LEAST grip, (I.E. the one that's slipping) gets the power. If you want power distributed equally to both rear wheels, you need a posi, or locking differential of some sort.

 

You need to learn how differentials work. An open differential always sends the same amount of torque to both wheels, that doesn't mean they will spin at the same speed. For example say it takes 200 ft-lb of torque to move a vehicle, but one rear tire is on a slick surface that it only takes 50 ft lbs to spin that tire while the other side has good traction but it is only getting 50 ft-lb of torque which isn't enough to spin that tire. So in this case only one wheel is spinning, but they are both receiving the same amount of torque ( 50 ft lbs) which isn't enough to move the vehicle. A limited slip/ Posi uses clutches or gears to transfer torque to the wheel with greater traction, and a locker will make both sides spin at the same speed regardless of how much traction each side has.