I just bought a 2001 XJ, kind of a project for me. Its in pretty good shape, all stock, 130k miles. No owners manual though. My first experience with Jeep, mostly a Ford guy. I was wondering, can you shift from 2 Hi to 4 Hi on the go, or do you need to stop?
Thanks,
AndyB

 

You can do it while moving. I like to slow down to about fifteen mph and then throw it in 4 hi.

 

I've shifted into 4 hi at 50 before with no problems I know it's not good but I wanted to see if it would work that high.

 

i dont think that will hurt anything, but how often do you need to throw it into 4 wheel drive at that speed? should prolly be already in?

 

I have a 90 and the manual in it says something like "... At any legal speed". So yeah shift it on the go.

 

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".

 

Makes sense. I've been only shifting while stopped. I thought something was wrong because the part-time light wouldn't go on. Then I drive slow for about 50 feet and the light comes on.

 

Has anyone have the t-case shifter pop back into 2hi from 4hi at higher speeds? A couple times I was in 4hi going about 50mph (don't ask me why lol) and it just popped back into 2hi. Very concerning.

 

Personally, i ALWAYS stop and put the transmission in neutral before doing any kind of Tcase shifting.

Seen a NP231 blow a case in half shifting from 2hi to 4hi at about 35mph.

Thats just me though

 

The NP231 you are supposed to stop or very low speed and go into neutral then switch to 4wd. the NP 242 it has the full time so it wont actually put it in 4wd unless there is slipping in the traction.

 

i always shift into neutral then shift into 4hi at any legal speed.
or in my tj, i just throw in the clutch to shift into 4hi.

 

Actually, when selecting any range on the 242 it will provide its design function in that range, 2WD or any 4WD range. In Full time, the front wheels are coupled to the rear wheels through a differential that allows the front and rear axles to turn at different speeds. In Full Time, the front axles are in fact under 4WD, whether slipping or not. In any other range besides Full Time, the 242 is similar to the 231.

 

then why does the sticker from the factory say that on my visor? and why can i put it in Full Time and make a tight circle, in lets say mud, and get zero binding but once i give it to much gas it front wheels start to spin and i get a lot of binding. if i put it in Part Time and try to do the same thing i get binding right away and cant make a circle or turn without getting binding.

 

Wow! Alot of misconception here! You can go from 2wd to 4w High at any speed, period. To go into 4w low however, you must be at a complete stop and have the transmission in neutral to get it in without grinding. Any 231 that "blows apart shifting into 4wd" was either done at full throttle or some dummy tried to put it into low while moving! The 231 is designed to be shifted into 4w high on the fly, I've had 6 jeeps with that t-case and never ever had any problems shifting on the fly.

 

Do you have a NP/NV242J in your XJ?

The sticker behind my sun visor doesn't say anything like you put in your post. "the NP 242 it has the full time so it wont actually put it in 4wd unless there is slipping in the traction." I suggest you re-read your sticker.

As far as "make a tight circle, in lets say mud, and get zero binding but once i give it to much gas it front wheels start to spin and i get a lot of binding.", it's called PFM!

If you don't believe me, the next time you are going to have your Jeep up on a hoist, put it in Full Time and have someone start the Jeep while it's up in the air...then you go and grab the front wheels.