My 2000 Cherokee limited has this case with full time/part time modes. Now I thought full time could be operated on pavement, but when I tried this it hops on tight corners as if the diff were locked. WTH? Also, in either mode you have to drive 20 ft or so before it engages. Seems kind silly, because if I get stuck I'm basically screwed....

 

Ok, first DO NOT engage your 4x4 on dry pavement if you value your transfer case! Full time 4x4 and All Wheel Drive are two seperate types of drivetrain. Your t-case has 2wd, part time 4wd, full time 4wd, N and 4lo.

2wd: Normal everyday driving on hard surface roads. No need for advanced traction.

Part Time 4wd: Use this when there is some snow on the roads but they are not completly covered. Allows some wheel slip before providing traction. You will probably experience some wheel hop if on dry roads. DO NOT use if roads are completly dry. Only if there is something on the surface that will cause a loss of traction.

Full Time 4wd: This option gives you the maximum amount of traction. Gives power to all 4 wheels which is why you felt the front end hopping when you were driving on dry pavement. You can only use this on surfaces that require maximum traction like snow or mud or sand. NOT ON DRY ROADS. Remember this is not the same as All Wheel Drive! All wheel drive allows slippage at each wheel to prevent the wheel hop. It allows the inside wheels to slow while turning which prevents the wheel hop that you felt.

4LO: This option provides you the same amount of traction as Full Time 4wd but it changes the gearing to a much higher gearing. So you will limited by your speed but your pulling ability is greatly increased. If you happen to be out wheelin or driving in the snow and need to pull some one out, this is the option for that.

Now for you issue of it only going into gear after driving a few feet. The NP242 has a history of being VERY tricky and irritable. Make sure the fluid isnt low and is in good condition. Climb underneath and check the linkage and make sure there isnt slack or nothing is bent and or broken. Also, my last XJ had this t-case and it was very irritable if my tires had unequal tire pressure. Make sure your tires all have equal PSI. If it still wont work well for you, take it it and have it serviced and or rebuilt. The NP 231 in most XJ's in my opinion is the better and simpler option. Good Luck!!

 

Actually this part isn't correct.

Full Time 4WD on the Selec Trac systems can be used on ANY road condition, even dry roads.

 

Not soo sure about that. I know the one I owned would never let me do that AT ALL. It would hop around real bad like a normal 4wd high. Mabey someone else has had a different experience but not this guy.

 

You should be able to use full time 4wd on pavement (open differential). If you're getting wheel hop, something is not right with your transfercase.

 

2wd: Power only to rear driveshaft. Front driveshaft disconnected from engine power.

Part Time 4wd: Front and rear driveshafts powered at the same time and are "locked" together. Should not be used on dry or high traction surfaces because of potential differences in speed between front and rear axles.

Full Time 4wd: This option gives you less traction than part-time 4wd. Front and rear driveshafts are powered but through an "open" differential in the transfer case. Good for all surfaces. In full time 4wd with "open" front and rear differentials, any of the four driven wheels can spin.

4LO: Same as part-time 4wd but uses a gear reduction in the transfer case to amplify torque available to the wheels. Front and rear driveshafts still "locked " together. Use this option for maximum traction and low speed control.

Any chain driven transfer case (NP208, NP231, NP242) should have regular fluid changes and also should be "exercised" (put in four wheel drive) every few months. This insures that the shift collar in the transfer can slide freely when needed. I also find that a quick shift of the transmission into neutral (for an automatic) or a clutch release (for manuals) helps to shift from one range to another.

 

As far as I know, full time 4wd mode is not as an open diff. It splits the torque 48% front, 52% rear. I use this mode all the time, gives far better traction on wet roads.

Rob

 

Hi

I have 2WD 4WD/Pt 4WD/FT N 4WD/LO and my handbook states 4WD/FT can be used on ANY road surface which we do unless dry weahter then we switch back to 2WD.

To select I have found if you put the lever into the desired option then shift the select R the D a few time and wait for the light to come on.

The hopping you experianced was because Part Time was still enganged shifted as suggested has always stopped this from happening.

If the problem persists try changing the oil in the Autobox and the T case.

Stuart

 

x2, fulltime isfor all road surfaces, parttime for max traction slippery loose surfaces. (I know I own one LoL!)

 

Then your transfercase didn't work right or the shifter wasn't adjusted properly. In the owners manual it clearly states on the 242 you can drive on any surface.

 

Absolutely. I've owned two of them. ANY road surface, including dry pavement is fine for Fulltime 4WD.

 

Seems to be some controversy on how its supposed to operate
My impression was that the center diff is unlocked during full time operation, which is what some of you guys have mentioned.

 

Yes... Why not just read the owners manual?

 

Ummm....cause this is a 10 year old vehicle and didn't come with one.

 

99 and 2000 FSMs

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