If the fronts are unloaded on a steep loose hill, the VTD with clutches does not do enough to prevent too much torque fm going to the fronts. I have never failed a climb due to traction but the car has struggled mightily on a few occasions. A rear locker would not have helped in those situations. A center lock would have. In its absence, momentum is the only friend.
Ergo, with a locked diff you are still going to get an approximately 50/50 split front and rear regardless of how much spin there is in the front.
Yes that's right. If you have diagonally lifted wheels & both diffs are open, doesn't matter what kind of centre diff you have. Locked or open, you're going nowhere.Without a locked or limited slip rear diff, as soon as the diagonally opposite wheels lose traction you are stuffed, isn't that right? or would this also occur if both wheels on one side lose traction, even with a DCCD?
there must be reason why subaru's DCCD was never used on more offroady models as forester or outback. maybe its just don't work on harsh off road conditions or its not better then good old VDC and x mode. And DCCD must works with LSD's to do its job best.
However once the hill becomes two steep the 4Kg centre will not transfer enough torque to the rear axles to push a car up. You really need centre and rear locked to get the full benefit on steep inclines.