My son has a 1999, 2500 Ram, 4X4, that is on it's 3rd transfer case. Each of these has developed a problem over time, where, when the truck is in 2 wheel drive, going down the road, when he lets off on the accelerator pedal to coast, the transfer case will pop in neutral.

Anyone else have this problem, or any suggestions as to what transfer case to buy that will eliminate this problem?