What NOT to do when crossing an ice covered bridge

Your understanding of how inter axle differential works seems to line up with my thinking. I think it was one of our friends from Ontario that noted he engages it in October and takes it off in May, or something to that effect. Seems like there is a lot of confusion about this point among drivers that may be a carryover from the "bad old days" when IAD's weren't so robust. If it helps increase traction in slippery conditions then I'm all for having it engaged.

That's possible. My bet is that he may have had the cruise control set when he hit the bridge, the right side drives lost traction and started to spin to start the skid and he may have hit the brakes to kill the cruise. Two fatal errors in that situation.

Regarding the clutch theory I think that's an option to consider. From my experience a couple of weeks ago just backing off the accelerator and steering into the skid quickly resolved the skid and straightened me out. In any case the idea is to remove torque from the drives and let the wheels to allow them to spin freely is the key. This is why having the jake on in icy conditions is such a bad idea, you go from possible torque going forward to sudden torque to slow down and that puts too much stress on your tenuous traction.

Regarding having the inter axle differential engaged, I think having the ability to apply slight acceleration as needed is something I'd want to have in the bag. It certainly helps when climbing a slippery hill. A few days ago I was driving a slight rise around a curve in packed snow and ice and had to maintain a bit of accelerator to make the climb and steer to the outside of the turn as I went to climb to the high side of a sloped road. If I didn't have the IAD engaged that would have been much more difficult.

Getting bashed here isn't so bad if this thread helps someone in the future recover from a similar situation.

I agree he was going fast for the approach to that bridge. It looks like the road is bare and dry before and after the bridge, but that bridge needed to be approached without throttle. Note that after the tractor is starting to skid sideways as soon as it hits the bare and dry pavement on the far side of the bridge the nose of the tractor dips down as the right steer takes the weight of the truck and rockets it toward the median. Similar to braking into a hard turn, it made the turn happen quicker.

 

I understand. Some just aren't trainable.