This is straight out of the 2001 owners manual in section 5 page 135
2h TO 4h OR 4h TO 2h
Shifting between 2H and 4H can be made with the vehicle stopped or in motion. If the vehicle is in motion, shifts can be made up to 55 mph ( 88km/h). With the vehicle in motion, the transfer case will engage/disengage faster if you momentarily release the accelerator pedal after completing the shift. Apply a constant force when shifting the transfer case lever.
4H to 4L or 4L to 4H
With the vehicle rolling at 2 to 3 mph (3 to 5 km\h), shift and automatic transmission to N ( Neutral) or depress the clutch pedal on a manual transmission. While the vehicle is coasting at 2 to 3 mph (3 to 5 km\h), shift the transfer case lever firmly to the desired position. Do not pause in transfer case N ( Neutral)
NOTE Pausing in transfer case N (Neutral) in vehicles equipped with an automatic transmission may require shutting the engine OFF to avoid gear clash while completing the shift. If difficulty occurs, shift the automatic to N (Neutral), hold the foot on brake, and turn the engine OFF. Make shift to desired mode.
NOTE Shifting into or out of 4L is possible with the vehicle completely stopped, however, difficulty may occur due to the matting teeth not being properly aligned. Several attempts may be required for clutch teeth alignment and shift completion to occur. The preferred method is with the vehicle rolling 2 to 3 mph (3 to 5 km\h). Avoid attempting to engage or disengage 4L with the vehicle moving faster than 2 to 3 mph (3 to 5 km\h).
I hope that helps
I am finally on board with obama's hope and change thing. I now HOPE
that when its all over I have at least a little CHANGE