what I have is 1983 K5 with the stock 208 transfer case and non locking hubs. It seems to be stuck in 4 hi. I have driven it in 4 hi and then backed up and shifted back to 2 hi while driving foreward again and it comes out of 4 hi... BUT When I get out(engine running and in park) and turn the front driveline with my hands it locks up.
I removed the driveline so I can look at the transfer case and the front
differential independently. I had someone drive it slowly while I looked underneath (its lifted) the yoke at the front differential spins when the wheels roll. The yoke at the transfer case end also spins.
Any ideas on what I should be looking for so I can diagnose where the problem is coming from?
It drives fine without the front driveline in. It drives like gears are catching and grinding with front driveline installed.
Thanks

 

When the front driveshaft was out, after you saw the front yoke turn when you thought you were in 2HI, did you try to move it by hand. There may be some drag inside the transfer case.

You also may not be completely engaging 2HI. Look at the shifter where it attaches to the side of the transfer case. The linkage should have an adjustment. Watch the way it works when you put it into 2HI and adjust it to get a bit more travel out of the lever that goes into the transfer case.

 

The front driveline is out now and the transfer case yoke spins freely when the engine is off. I don't hear any grinding it is smooth.
I tried to spin the front differential yoke and that only moved slightly and clunked and will not spin when I try to move it with my hand. (The front driveline is removed)
I will check the linkage tomorrow.

 

Sounds like the transfer case is working properly and you just have some residual drag that is turning the yoke when the driveshaft isn't there.

I would put on a set of manual locking hubs so you can make sure that they unlock properly as well as lock up when you need them!

 

Thanks. That is what I will be doing today.