92 Cherokee front axle engagement Q's??

[Mercenary]

I am terribly confused. I own a 92 Cherokee with th 242 x-fer case and I am having a heck of a time getting it to engage and disengage 4wd. It takes forever sometimes. I assumed that the whole problem was due to the vacuum disconnect system, but now I find out that there is no vacuum system on the 92 cherokees with the 242.

Is this the case? How does the front end engage 4wd? If it was a full time x-fer case, wouldn't 4wd engagement be instantaneous and vice versa for disengagement?

Please educate me as to how this system works.

Thanks.

 

[Yucca-Man]

Just to make it more confusing, the 242 didn't have a vacuum-disco anyway. Once the vacuum disco was finally removed from the 231, it ran the same way as well. The non-disconnected axle turns all the time, and the t-case is internally disconnected to allow 2wd.

 

[Mercenary]

Ok. Lets see if I can get this straight. The x-fer case connects the front driveshaft to the engine (basic, I know pls bear with me) The front end axles are connected to that driveshaft. What connects those axles to the front tires?? I mean, a conventional system has the hubs to engage and disengage the front tires to and from the axles. So in this Cherokee system, the axles and wheels are permanently engaged? Wouldn't 4wd activation be instantaneous? Pull the lever to 4wd P/T and it pops right in?? There has to be some moving part besides the x-fer case lever that engages the 4wd system on 92 and up XJ's, right??

I am so confused right now it aint funny.

Please set me straight here folks.

 

[Yucca-Man]

The non-disco axle is always turning. There are no automatic hubs in the front axle, and as you know there is no way to lock/unlock them manually either. This comes up in the OEM section every so often as the newbies notice that their driveshaft always turns, making them think that they are in 4wd.

Since the t-case internals control whether the Jeep is in 4wd and yours isn't shifting, my guesstimate is that you've got some t-case issues. I don't know enough about troubleshooting a 242 to provide guesses though but hopefully that gives you something to look at.

 

[woody]

Ok. Lets see if I can get this straight. The x-fer case connects the front driveshaft to the engine (basic, I know pls bear with me) The front end axles are connected to that driveshaft. What connects those axles to the front tires?? I mean, a conventional system has the hubs to engage and disengage the front tires to and from the axles. So in this Cherokee system, the axles and wheels are permanently engaged? Wouldn't 4wd activation be instantaneous? Pull the lever to 4wd P/T and it pops right in?? There has to be some moving part besides the x-fer case lever that engages the 4wd system on 92 and up XJ's, right??

I am so confused right now it aint funny.

Please set me straight here folks.

The transfer case engagement is mechanical... When the lever is pulled back into 4-high or low (part time) the case will output torque 50/50 front and rear. The 242 in 4-high (full time) engages a center differential that allows some slip front to rear, allowing it's use on dry roads without binding...

Either the 242 or 231 should allow shifting in & out of 4-high "on the fly" up to 55 mph or so.

I had a 242 that confounded me... sometimes the front shaft had output, other times not... 2-low on a random schedule makes a driver do things differently.

Try to scrounge up the FSM spec on adjusting the linkage, and see if that helps. You will need a short 13mm wrench or socket for the adjuster bolt.

 

[JJacobs]

242 shift issues could be the shift fork and mode fork wear pads. They ride in a groove on the engagement collars, and when the plastic wears out you get slop and metal to metal contact when shifting. Sometimes the bushing in the front of the case that holds the shift rod will loosen up as well.

Ultimately, I wouldn't be surprised if that 242 has a blown up center diff, since a lot of them end up that way. Might want to pull the rear half and look things over.

 

[Mercenary]

Ok. It is slowly becoming clearer. I am beginning to understand a few points but I am still struggling with why my x-fer case takes so long to disengage from 4wd. From what I understand, it isn't the front axle at all that needs to "release" but the x-fer case itself. So, it must be centrifical force and the actual x-fer case shift fork that keeps the Jeep in 4wd when driving, right? There needs to be an internal mechanism in the x-fer case that has to disengage the front axle from the x-fer case, right?

 

[Yucca-Man]

From what I understand, it isn't the front axle at all that needs to "release" but the x-fer case itself.

Bingo. That's why we're leaning toward a t-case issue.

What led you to believe you don't have 4wd, by the way?

 

[Mercenary]

I do have 4wd. What is happening is that the x-fer case is taking a long time to disengage from 4wd. I drove damn near 30 miles the other day, trying like mad to get the x-fer case to disengage.

I drove up a steep hill, played around on top of the hill for a bit and then headed home. It went into 4wd just fine, but I dropped it out of 4wd after I crawled down the hill in 4lo. I drove approx 5 miles on dirt road and the rest on highway. I sped up, slowed down, coasted in neutral, stopped and backed up, everything short of getting out and kicking it to try and get that sucker to disengage. The indicator light would flicker a couple times and it even went off when I stopped the Jeep, but it would come back on as soon as I began to drive again.

So.. when you throw the lever out of 4wd back into 2 high, what actually disengages the t-case? Would a conversion kit such as the one supplied by Warn make any difference?

 

[98JeepXJ]

Ok, just a random suggestion here, I'm surprised it hasn't been said already. Have you happened to check the air pressure in your tires lately? Are all your tires the same size and have about the same amount of tread on them?

The reason I ask is because the 242 case is finicky about having all 4 wheels turning the same speed to engage and disengage 4wd. If a tire is significantly low on air, it's diameter is smaller and it will turn at a different speed than the others. The same holds true for a tire/tires having a significant difference in tread depth...

Just a thought...

 

[Mercenary]

98JeepXJ: Why would that make such a huge difference? Why do all the rotating elements have to be spinning at or near the same rpm for the 4wd engagement and disengagement to work properly? I do have two brand new tires on the back and old ones on the front. They are the same brand and tire size, but the front are at about 50%. I know there would be a ratio difference here. Would I prevented from getting the lever into 4wd if there was such a large discrepancy between the front and rear tires?

I do admit that I prefer my old Chev Blazer with the front hubs and the 205 t-case over this set up. When you threw that sucker in and out of 4wd it was instantaneous.

I thank everyone for their input. Please keep it coming.

 

[AZ Jeff]

The inside of the transfer case (either the 231 or the 242) contains a sliding sleeve that goes over a tooth type spline on the shaft. (There are mating splines on the inside of the sleeve.) When the XC lever is moved either direction, it moves the sleeve accordingly.

The sleeve tends to bind on it splines whenever rotational load is applied to it. Thus, getting the sleeve to move when load is applied can be challenging.

The solution, of course, is to not be applying load to the sleeve when moving it via the lever. The trick here is that when coasting/decelerating, you are apply a load just as you are when accelerating. The sleeve must be in the exact "float/no load" position to slide easily on the shaft.

On my old 1992, I had this problem even when I had 4 tires of the same brand, size, and inflation pressure. I found the trick was to be "almost stopped" when moving the lever (moving at a slow walking pace). Even then, it sometimes would balk to shift, so I would have to put the trans in reverse and be almost stopped that way to get it to slide.

Your XC may be balky, and this suggested method as I used to use may solve your problem. If not, then it's probably time to tear into the XC to find out what's causing the severe binding.

 

[Mercenary]

AZ jeff: Ok, so if there was a problem with the shift lever linkage, then I might not be getting enough contact with the teeth on the sleeve with the teeth on the shaft. I can pull the lever into all shift positions easily. There is no grinding or any difficulty at all trying to get the shift lever into the right position.

 

[sjx40250]

I have three Jeeps with the 242, the oldest is a 90 which I bought new. The comments on tires is quite true. My habit in shifting in and out of 4WD is to do it on the straight while accelerating then let off the throttle. I usually then hear a very low volume clunk as it shifts. You won't notice it unless you listen for it. The Lights are not always in sync with the shift.

I would get uniformity on the tires first then check the operation then attack the adjustment.