Some say the Slec Trac system in the Grand is not so hot. It sounds like an AWD And part time 4WD system to me, but I guess I dont know the specific differences between various AWD systems

Years back I had a ford Explorer with AWD (not 4WD like 96% of them had) and ABS and nice tires (after the firestone recall) The thing was great on road in slippery driving, but
it got cross-axled once in a dirt driveway up in Maine when one wheel fell in a gully and the diagonally opposite wheel got lifted in the air
ie, one wheel on BOTH axles was up in the air
From what little I know, I dont thgink part or full time 4WD or AWD would have worked in this situation
I think the only thing that would have worked is a diff locker where I could have gotten one of the non-spinning wheels to drive, correct?

I want some cheap winter transportation that is capable
by capable I mean I can drive in AWD on the street AND use it in an off road situation
Cheapest solution seems like a low miles Grand with 6 cyl, ABS and install a diff locker (hopefully that does not cost too much)

Comments?

 

Viscous Coupler instead of a gear-differential. The VC fails. Even some stories of running different tires will cause it to fail. i.e. a new vs a worn tire of the same model/make. Of course the tire shops take that story and go crazy to sell more tires.

 

Part time 4WD means the front and rear driveshafts are locked together and both turn at the same speed all the time and it's not friendly to driving on high traction surfaces, like a locked differential. With full time 4WD or all wheel drive the driveshafts are both driven but can turn independently within the transfer case making it easy to turn on high traction surfaces, much like a left & right axle do with an open differential. If it has a viscous coupling in the transfer case it's kinda like a limited slip differential in the transfer case, both driveshafts are driven and can turn at different speeds but some power will be transferred to both even if one end is loosely spinning.

As for the situation where you got stuck, lockers or limited slips may have gotten you out. A trick with open or limiteds when one side is spinning is to power brake it. Brake pressure will try to hold the spinning tire forcing power to the tire with traction, you'll have to play with how much brake you apply to find a happy balance of enough to slow the loose wheel while not so much that the traction wheel can't move. This will work with an AWD or full time 4WD as well to control the front or rear from free-wheeling. Whether trying to 'lock' a differential or transfer case, if it's only rears that are slipping you can use the parking brake for power braking so that the fronts aren't fighting brake pressure making it easier to get moving again.