Thanks guys. Read the article on the shift motor. Very interesting stuffs.
Just to make sure things are clear here....when I turn the knob to 4-low(example) it shifts to low gear, but only the rear-end is doing any work. Just after I bought the truck, I went to play in some sand with it. Had it in 4-low, but almost buried the rear end...the front was no help at all....but it WAS in low gear. The drivetrain DID shudder hard a few times when I hammered down. Not sure if that was the rear-end locking up, or the t-case trying to finnish shifting.
Just wanted to mention that...just not sure if the shift motor would still be at fault here.