It goes into 4HI without hesitation about 85% of the time, and almost always makes a clunk/grind going into 4LO (this is in N on the automatic).

It 4LO it has really harsh engages into Reverse and Drive, like as in I'm attempting to drag race and am launching the car. It also grinds going into Park while in 4LO.

4HI has very little problems: every now and then it might clunk when going into 4HI ... and that's about it.

Now this is my first time even owning a 4WD, so I'm sorry if I sound really inexperienced in this area of work, because ... well ... I kind of am.

2HI has no problems whatsoever.


I jacked up my truck and held both the front and rear wheels off the ground using jack stands. I started the engine, put the trannyinto N (this is the only spot my Jeep will allow me to shift the drive-train), shift the TCase into 4WD (doesn't matter whether in HI or LO), then put the tranny into D, and the front wheels didn't spin. I noticed during this test that if I have it in 4WD long enough in Drive (with the rear wheels spinning), the transfer case will begin to make a clatter, almost a grind.

So my question is: is my transfer case going/gone? How easy will this be to fix?

If the TCase IS gone, I will probably just get a junkyard one along with the manual tranny when I go tranny shopping for my auto to manual conversion project.

 

Does your front driveshaft spin in 4WD? I think you have the vacuum disconnect front axle.
It won't shift in and out of 4X4 in drive while moving? Foot off gas, shift transfer case, foot back on gas?

 

I have a similar problem with my 95 cherokee, 175k. In 2wd as I slow down I can hear what sounds like a shaft knocking. But in 4 hi, and going really slow, it seems like I can hear the gears in the Tcase slapping together. I am not able to get into 4Lo or N on the Tcase. I also have not checked the gear oil in the Tcase or differential on the front axel yet. I also am new to 4WD. Any suggestions? Is my Tcase shot?

 

87 XJ will have the vacuum disconnect front axle which feeds off vacuum pressure from your t-case. (red,yellow and blue or green air lines) which typically get split or leak so there's not enough pressure to shift the fork for the front to engage.

I would look for a non disconnect axle from a 91+ XJ and swap it in... no more vacuum issues for 4wd.. or do a cable lock to manual shift your CAD for the front to engage.

As far as your tcase it could be something as simple as the shift linkage is out of adjustment

 

Start with this:

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".