this morning at 1 degree,COLD, I started out on hard snow packed roads. I was in hi lock from yesterday. I tried a number of times going slow, stoping, in neutral, backing up. it would briefly change lights , all out, all on,but back to lock, and went 7 miles on snow so it didn't hurt. finally it released. I assume it was just too cold to shift and now I will be sure to go to 4 high while warmed up driving.
I really wonder what happens to the motor/mechanism when it gets stuck?
is it stressing stuff? future trouble?

 

If you were driving on snow then there should have been no adverse effect at all. That is the kind of condition Hi-lock is intended for.

I suspect even on dry pavement for 7 miles would not do much harm as long as you were not making a lot of tight turns. Not good for the vehicle but probably not that bad. If the wheels are skipping in Hi-lock then you are surely putting additional stress on drivetrain components. How much stress will cause a future problem? Probably hard to quantify.

 

yeah, so far so good. I went in and out ok today. I also read the svc manual for something to do.
it tried to shift and failed. the book says two things. if the lites flash for 15 seconds and stay where it was , the controller is missing some info from elsewhere. that's not the case. 2, if they flash briefly and stay without shifting there is/was binding in the case. ?
the only thing I could imagine was the cold weather, but why? and why is it ok now.
I might question a dealer svc since its in warrantee.
I don't like mysteries!