it ROLLED and I kinda fubard one of my skid plates because my dam jack is too hard to release, I didn't notice the front tires spinning either, the only thing I can add to this is that my parking brake needs to be adjusted I guess I drove around on it for a couple days about a month or so ago and I haven't adjusted it yet, I didn't have it on of course to test if it rolled, so unless the awd utilizes the parking brake in some manner then it is what it is.just to make sure i understand, your yukon was parked like the pickup in your sig, u jacked the front and it rolled forward? did it roll a little or a lot like u think it wouldnt have stopped?