2002 Sport Trac 4x4 won't shift back into 2 low

[dpep4]

I'm new to this forum and I'm finding it very helpful. However, I yet to come across an issue I've been having with my 02 Explorer Sport Trac. The problem is, when I shift from 2wd to 4wd High while "On The Fly" it will shift and the light on the dash will come on showing 4Hi. However, when I shift back to 2wd, while "On The Fly" it will not dis-engage. The light on the dash will go off, showing it's back in 2wd but I can feel it's still engaged because it's pulling like it's engaged.. The only way I can get it to dis-engage is to, stop the vehicle and turn it off. Any ideas as to what it might be, the xfer case motor, or the 4x4 module, or something else?

Thanks.

 

[600remguy]

Have you got any wildly different tires anywhere on the unit? Excessive torque caused by different tire size will affect the disengagement especially on a hard, non slipping surface.

 

[ncranchero]

I don't know if it's the GEM or the 4x4 module. My F150 did that a couple of times but it wouldn't come out of 4Lo until I disconnected the battery. Only happened a couple of times and I couldn't make it duplicate the problem.

 

[dpep4]

Have you got any wildly different tires anywhere on the unit? Excessive torque caused by different tire size will affect the disengagement especially on a hard, non slipping surface.

I thought it might be the tires causing the problems because they were all worn down some what, so I replaced them all. (I rotate them about every 5000 or 6000 miles.) I have only used the recommend manufactures size.