Hi, newbie here. Can't find this problem in any post. I noticed this weekend that the front wheels on my suburban were not engaging when in 4 wheel drive. This unit has the push buttons on the dash which light up and show the proper selection. I lifted one front wheel, and when in 2 wheel, the drive shaft doesn't turn, but when in 4 wheel, it does, so I think the diff is fine. However there is no action in the front when driving in 4wd (rear wheels spin, but not front). I hear the actuator on the transfer case work when shifting between 2 and 4 wheel drive. No trouble lights on. Some times there is a slight clunking sound in the transfer case when going in and out of 4wd. Does this mean I should look for a rebuilt transfer case? Or could it just be the actuator that is the problem?