can anyone expain to me "part-time 4x4" and "full-time 4x4"? I took the stock xj out for the first time this weekend and was wondering when it switches between the two and what causes it. Any help would be appreciated.

 

part time- use this part of the time you are driving. don't use it on hard dry surfaces.

full time, you are able to use that at anytime. it can constantly be in this mode.

 

Part time- offroad ONLY
Full time- whenever the hell you want, just expect bad mpg and faster tire wear.
4LO- counts as part time, only use on loose surfaces.
Your owner's manual should explain the modes also.
Do not drive over 35 or so in part time, 45 in full time, and like 15 in 4LO. 4LO is only really needed in deep mud or snow. Part time and full time should get you out of most situations.

 

I thought you could shift into 4 at any speed up to 55? Not that you'd ever be going that fast in conditions that need four-wheel drive, but it is possible?

 

yes you can, but i would not recommend it.

 

I know I've shifted ~50 w/o issue. I don't know if I've seen anywhere (maybe not remembering?) about higher speed shifting... Is there text that can be referenced?

 

i get all that stuff but is there something that manually shifts it from part time to full time? When i put it in either 4high or 4low, the only light that illuminates on the dash is the part time one. My thought on the whole thing is, you're either in 4wd or your not

 

I just wouldn't shift into 4x4 at high speeds period. It can screw up the whole system. I usually stop, put the tranny in neutral, shift it into the 4x4 mode I want, then put it back in drive. It ensures it goes into the right mode properly. millbro, it should light up green and say full time, orange and say part time. 4LO will still light up as part time. I don't know if a 99 is exactly the same, but thats how my 89 is and I doubt they would change it. I assume you have the NP242 selec-trac transfer case right? If not, you have the NP231 command-trac transfer case. In that case, you only have 4HI (full time) and 4LO (the second part time setting). You could also just have a light out. Or it may not register completely between the two.

 

i think it has the selec-trac transfer case. I was really just wondering how the transfer case decides what mode to be in. I really only want the part-time 4x4 to use off road, so i guess as long as the part time light comes on i'm good. Thanks for all the info guys

 

"Any legal speed" is a quote from an old owner's manual. I've done it at 80 MPH. No worries.

 

I have the select-trac in my 97 ZJ. Part time was explained to me as a locked 50/50. Power goes to front and rear axles equally. This is why you don't use this on dry surfaces/roads. Full time is a 48/52 split, which allows the power to sway one way or the other so as not to bind the drivetrain. This makes it possible to run 4wd on rainy roads and such for better grip without fear of wearing your drivetrain too much.

Just how it was explained to me

 

Its called part time cause u decide when to use it..as soon as u pull the lever into 4 hi or 4 lo ur in 4x4. And untill u put it back in 2wd ur gona be engaged 4x4 no matter what. Shifting into 4 hi at 50 I think is what my book says is the limit but I wouldent recommend it. Hope this helps. I have select track to..2000 xj

 

That wouldn't make sense, you also decide when to use the full time...lol

Think of it this way

Part time. You only wanna use it part of the time( off the road).

Full time- you can use it off road and then drie on the road without changing it

 

My select track does not have full time 4x4. I wasnt talking about awd either,
When I pull the lever into 4 hi ( or 4lo) its always 4x4 till I put it back in 2wd is all I was saying .... when in 4hi or lo it does not decide by itself when to be in 4 x4 or not, magicly.

 

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