Well, after my fiancee recently rolled her Xterra we have both been wondering if the fact that it was in 2hi at the time had anything to do with it.

This accident happened to occur while she was attempting to pass someone and lost control while crossing some slush on the centre line of the highway.

The reason she was not in 4hi at the time is because we have always been cautious of leaving it in 4hi while on non-slippery roads due to the transfer case 'locking' up.

My question is really how worried should we be about the transfer case locking up when being run on non-slippery roads and just how slippery should they be (minimum) to use 4hi without concern? Is just being wet good enough? This is with stock tires and the 5 speed transmission btw.

Thanks in advance for any advice on this:)

Bruce in Middle of Nowhere, BC, Canada

P.S.
Insurance company has decided to pay for the truck to be repaired and I am fine with that as the Xterra is not a unibody vehicle and I'm confident the shop will do a good job. I've taken other vehicles there before to be repaired.

If there was slush on the center line I would have had the hubs locked and shifted in and out 4 as conditions changed.

You're only going to see the driveline binding up if you are driving very slowly turning tight corners. If it's wet on the highway with patches of slush or ice, leaving it in 4 won't harm anything.

Putting power down to pass while in 2WD and encountering slush and such is about the perfect recipe for the rear end to break loose and side-step causing a loss of control. Even crossing the mound of slush while off the throttle is tricky enough, it wants to throw the vehicle off-course regardless. 4WD would have helped, but even then it's twitchy and I am very cautious. Bummer about the wreck, assume she's OK. The X has been very good to people in rollovers from what I've seen.

Brent

Thanks for the help guys:)

Yes both her and our rather large dog escaped any real injury at all which is part of the reason we chose the Xterra as it looked like it could take a few hits (we have ALOT of moose on our commute) and if not keep goin at least let us walk away.

$7500 (Can) in damages so far in case you were wondering. Body-man hasn't looked at it yet so I expect it will go up to $10k tops.

Bruce from BC.

Wow, gotta watch that damn slush. Ian's advice is solid and has served me well in questionable conditions. This time of year, I pretty much keep my hubs engaged (locked) 95% of the time (unless roads are perfect). I shift in/out as the need arises.

Two big rules to follow when changing lanes in slush:

1. 4H is KEY (she found that out)
2. Slow WAY down, change lanes, speed back up.
3. Optional rule: get better tires.

Glad to hear the wife and dog are OK.

-dp

Two other techniques you might consider in mixed conditions.

In mixed with less slippery/more traction ratio-If you lock hubs (by engaging them below 25 MPH) then shift out of 4wd, you can engage and disengage at higher speeds. If you try this, remember that reversing direction will unlock the hubs if in 2wd. So you will have to repeat the process again if say you stopped to get a coffee or something.

In more slippery, but still mixed conditions-Engage 4wd and keep it in 4wd. Occationally, and carefully wander one side of the vehicle into the edge of the slush or compacted snow to allow some binding relief. It doesn't take much, so don't go wandering all over the road. Its a judgement call.

By the way, I don't tell my wife to do this as she would likely mess it up. She is very smart, but just doesn't pay attention to these types of things. But the above techniques have worked for me on numerous occasions. If you don't understand the techniques as I described them, then I don't recommend trying them until you do.

Bad advice. First of all, you can cruise straight all day in 4Hi on bare pavement if you like, it's turning that causes the problem. When it does, it just takes a matter of moments, you need to be on a low-traction surface the whole time. Advising someone to stray out of optimal traction into sketchy traction isn't wise and inviting trouble. Other than for kicks, I stick with the best traction available. As demonstrated above, having one side suddenly encounter a sudden difference in traction, especially coupled with a severe case of drag such as a mound of slush, can quickly lead to disaster.

Get the Bodyman, to get you an ARB type bumper...