4 wheel high

I took my 88 xj out into last chance canyon yesterday and noticed some weird sounds coming from what I assume was my transfer case. The only time it happened was while in 4 high. It was intermittent while driving. If I stopped and started again it took a minute for it to come back. Worst sound of all was in reverse. It made a fast grind sound. 4 low and 2 wheel were great All day long. As well the transfer case is very hard to shift from two wheel to 4 wheel drive. But going back to 2 wheel drive was fairly easy. Is there linkage that I need to check the adjustment on that could cause both things to happen,like maybe the t case is not engaging all of the way? Thanks in advanced

yes there is a linkage, yes it could be out of adjustment.

Hate to be Captain Obvious here, but have you ever checked the fluid level and condition in the case? All tires the same size and inflated to the same pressures?

I can provide factory shifting instructions and linkage adjustment if you want.

That would be great, tires are all good. I check them before I run. Oil is a good question though. The previous owner had an sye installed into it.

I always check every fluid level and condition on any "new to me" vehicle.

Should also check ball joints, u-joints, brakes, and grease every zerk fitting you can find.

Here's how the factory suggests you shift the transfer case and I've been doing this since these things were new and I worked at the dealership. Quoted from the owner's manual.

"To engage, shift the transfer case lever from 2H to 4H while the vehicle is moving at any legal speed". I let off the gas, throw the lever, and then tap the gas and let off.

4L position: " To engage, slow the vehicle to 2-3 MPH , shift the transmission to Neutral, then shift the transfer lever to the right and pull firmly rearward to 4L".


Transfer Case Linkage Adjustment
Straight from the FSM:

SHIFT LINKAGE ADJUSTMENT
(1) Shift transfer case into 4L position. (make sure your shifter is fully in the 4L position)
(2) Raise vehicle.
(3) Loosen lock bolt on adjusting trunnion (Fig.
87).
(4) Be sure linkage rod slides freely in trunnion.
Clean rod and apply spray lube if necessary.
(5) Verify that transfer case range lever is fully
engaged in 4L position. (you can do this under the vehicle at the transfer case)
(6) Tighten adjusting trunnion lock bolt.
(7) Lower vehicle

Thank you very much for the help. I will update on how this goes