Centre diff lock on AWD auto

[CNY_Dave]

Switch makes a world of difference when you are stopped facing up a hill.  Without it front wheels spin and the car starts to slide backwards and to the right, try it again with the switch, all four tires spin at once and I start moving forward.

 

The problem with the AWD is that there is about a 1/4 sec lag between slip and power transfer (for the TCU to calculate the difference and then activate the rear wheels) and if you are stopped on an icy anything, that 1/4 second can make the difference between being stuck and getting moving again.

 

I remember being in a ski resort parking lot years ago when I had my dual range gl-10 and I was stopped on an incline with a early 2000's outback in front of me.  Once the line started to move, the outback was completely stuck.  The front would spin before the back kicked in and they would start sliding backwards.  We all had to back down the incline and the let the outback have a run at it.  Once the outback got up the hill, I had to stop and wait on the hill again for my turn to park.  Once I was signaled to go, I took off with zero issues in the same spot the outback got stuck.  Having all 4 wheels turn at once is crucial to get going again if you are stopped, really on anything icy.

 

 

To get past this limitation, to a degree sufficient for steep slick hills, I put it in 1 or 2 and apply a small amount of throttle with the brakes on, as soon as the TCU sees off-idle throttle in 1 and 2 it applies a fair bit of 'lock' to the clutches, and there is absolutely no front-only wheelspin.

Edited March 23, 2013 by CNY_Dave