Gamefreakgc

I thought coming to a near or complete stop was common knowledge? I still have the caution card that comes with the truck saying what you just described. Has the OP been trying to shift back to 2wd while driving?

JasonYota

iTrader: (1)

If you have locking hubs in the locked position and have a non ADD axle tube you can shift between 2wd and 4wd at any speed. As long as it's not under acceleration or deceleration.

RJR

You should definitely not have to stop when going from 4Hi to 2Hi under any circumstances, and if the hubs are locked, or if you have ADD and a chain driven case (which has synchronizers), you can go from 2Hi to 4Hi without stopping as well. Inability to shift out of 4wd is a sure sign of things binding up. Mismatched gear ratios are a definite possibility.

Do the procedure below to find out for sure what gear ratios you have in each axle:

Figuring out the gearing is simple matter of counting. Assuming you have open diffs, here's the procedure.
- Jack up one wheel with the xfer case in neutral. Be sure to block the wheels still on the ground.
- Put an easily identified mark on the drive shaft so you can count revolutions.
- Rotate the wheel exactly 20 turns while counting drive shaft rotations. You may want a helper for this.
- divide by 10 to get the axle ratio. (for example, if the drive shaft turns 43 times, you have a 4.3 ratio. 45.5 turns indicates a 4.56 ratio, etc.

If you have a locker, it's the same process, except you need to jack up both wheels and turn the wheel 10 times while counting drive shaft rotations. After that, the math is identical.