I have a 89 jeep cherokee 4 L. auto with command trac I think,is just 2 wheel and 4 wheel high ,neurtral and 4 lo..We had some snow then rain and then it froze and in the morning I couldn,t get it into 4 wheel to get out of the driveway,is on a slope.I pulled up on the handle and the light went on but I didn,t have 4 wheel.After a couple of trys and trying to get out in 2 wheel it finally went in.Is this just a freezing issue or something that is starting to go wrong.It seems to engage fine for the rest of the day.

 

My '87 is hard to get out of 4HI. To get it in, I always make sure I'm going slow and forward, trans in D, then pull up on the 4HI lever. Green light goes on. To get to 4LO, I need XJ to be in neutral, going really slow, and pull it up while using my right thigh to push it to the right and then it goes into 4LO. Going from 4LO to 4HI is ok-again going forward but really slow. Sometimes going in reverse helps it get back to 2WD.

I had a '98 Suburban that went into 4WD with the touch of a button. I miss that! I also had a 1994 4Runner that went in to 4WD with a very easy slide of the transfer case lever. Not sure if all XJs are hard to shift in and out or not.

 

im my experience.. manual transfer cases are always a pain to shift into 4hi 4lo in cold weather.. not sure why... had a hell of a time with the hmmwv in the army at times.. my push button selector has me spoiled

 

If I am correct you have the 4x4 system where you have a vacuum actuated collar on the passenger side of your front axle. The axle should have a housing, similar to the one in the photo, attached to the passenger side. I have a 90 2 door XJ that has this system. When I put the transfer case into 4 high/4 low I usually turn my wheels side to side when I role forward. I do this because the collar, located on the front axle passenger side, needs to align with the splines of another axle shaft. Here is a picture of the inside collar I am talking about with the vacuum actuator,



(This is not my photo, but was found on google search)

Problems I have encountered with this system that could explain what is going on,

-vacuum leak or loss of vacuum at the actuator
-malfunctioning 4x4 actuator
-the collar within the axle is worn

Another thing I would check, is with one of the back tires off the ground, see if the front drive shaft spins when you engage the transfer case into 4 high or 4 low. This, assuming you have open diffs in the front and back, would determine if the front axle's vacuum powered actuator was actually working or not. If the Jeep didnt move, there would be no power being sent to the front. If it wanted to move forward, the axle has power.

It would also show if the transfer case was working. If it were me, I would start with checking if there was a vacuum leak and move on to bigger tasks.

Good Luck Bud!

 

2 things I wold do.

First, understand how the transfer case was designed to be shifted.

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".



Secondly, I would eliminate that roublesome CAD shifting crap. as NakedGinger mentioned, they can have issues. We had people coming in every snow day at the dealership with issues.

The issues were:

Vacuum harness to CAD either fell off or was broken.
Vacuum motor had failed.
Shift fork was bent. They went through 3 revisions of those..
The shift collar was seized on the axle splines in 2WD mode and wouldn't slide.

I ditch that crap first thing on any jeep with a 231 and CAD.

Here's how. Takes a half hour. There are no down sides. Doesn't affect fuel economy and you'll have 4WD when you need it.

BTW, how's the fluid level/condition in that t-case?

Here's the link:



https://www.cherokeeforum.com/f51/fr...ss-91-a-38629/