Contour Enthusiasts Group Archives Forums General Common Interests Chevy's "Auto" 4WD???

How the hell does it work? The manual says that it engages the transfer case but does not spin the front wheels untill the rear wheels loose traction. It sounds to me like it has both a front and rear locker. But I cant find any info about it anywhere. Im just curious because its going to start snowing soon and I need to know if I can trust the 4WD to automaticly kick in if I need it, or if I need to rely on myself to push the button.

Im confoosed.

I'm confused about it too.

But, most everybody is when I find something new and interesting to me.

Anyhoo, I did hear about a locking diff which came out a few years ago. The first wheel that would lose traction would trigger it to shift all traction to the other wheel.

But that on a 4WD sys? Don't know.

A friend of mine has something similar to that on his Escape. They say it is a 4WD but it only a FWD until the vehicle senses the front wheels start to loose traction then it engages all four. I doubted it when he first told me but he said it works great.

It's similar to the nissan skyline atessa system...

My wife has that on her '02 GMC Envoy 4x4; I had lots of fun with that little feature up in KS/IA/NE area last Winter.

A4WD does pretty much what the manual says; at a minimum, 1 rear wheel has to lose traction before the front wheels get driven by the front case. It's great for wet/slightly icy/slightly snowy driving as a small insurance policy, though when we had LOTS of snow or ice (OK, lots for KS and no snowplows in sight), it was all 4HI.

I wouldn't rely on it in particularly nasty weather, as if one were to get entirely stupid with a corner or takeoff, it would "engage" FAR later than I would be comfortable with in a real emergency situation. I found this out toying around with it on a deserted parking lot in KC last year. Again, you have to get pretty idiotic with the truck before you can "fool" the A4WD into engaging late, but it can be done and by the time it engages, you can have the headlights shining perpendicular to the road...

...which gives you traction at PRECISELY the wrong time and in the wrong direction, unless your objective is to leap your ride into a ditch/divider/oncoming traffic, etc., etc.

Once more, let me REITERATE that you have to be:

a) driving FASTER than you should in bad conditions and
b) driving like a bloody idiot in those same conditions

to throw the A4WD for a loop.

Murphy's Law/common sense/personal experience tells me to use 4HI in the nasty stuff and firsthand experience with the A4WD feature tells me to use it in the light stuff...

Find DESERTED patch of iced-up concrete to get the feel of it; you may find it entirely suitable for what you drive in.