Explain to me Jeep's 4x4

[jaysXJ]

I'm a young adult, just starting off and for the first time I got a vehicle that I was interested in and that wasn't a hand-me-down or a dumb decision(I had a lifted Ford Ranger gas hog and I had to sell it because I found out I have a kid on the way). My family is not into anything offroad or outdoors, so I've never had that influence. I got into a 2000 cherokee that I already love. I've always loved the infinite uses of XJ's and their never goes out of style look. In my Ranger's 4x4 system, it had a knob that was just 2wd, 4wd high, and 4wd low. I was taught to put it into Neutral to engage 4wd.

Anyways, I got the jeep 2 days ago, and I just now took it on a trail. so, since I was driving on a slippery muddy trail, I put it in N(transmission), put it in part time then Drive(I went slow and there wasn't many turns) and the ride was great. Once I got somewhere safe, I put the tranny in N and put it back in 2wd and went reverse and straight. I had to make a sharp right out of the trail, and my steering started grinding real bad. It felt like my 4wd did not properly disengage, or I did not disengage it properly. My steering wheel jerked back and forth. My first instinct was to think that the guy I bought it from screwed me over and rigged the 4wd to temporarily work or something. I pulled over, and repeated the process. It stopped within a minute. I read through forums and couldn't find anything too specific to my situation. When I went from part time to 2wd and the Jeep was still in drive, it didn't have that problem(Which I'm actually amazed by, because it makes the 4wd actually useful when you need it instead of having to park and put it in neutral or having to get out and twist some knob)

So my question is, how is the XJ's 4wd system different as far as settings go? can someone explain to me each of the individual settings and uses? The jeep didn't have the owner's manual, and I want to understand my 4wd system better. I would also like to know why there is a Neutral position for the 4wd before the 4low.

Thanks in advance :)

[cantab27]

howdy jordan , welcome to the site mate.......have a read through here mate....

Jeep four-wheel-drive systems - Wikipedia, the free encyclopedia

got most things in there ........they are a good wee 4wd mate...good choice

[jaysXJ]

what is the name of my jeep's 4wd system?

[cantab27]

1987–2001: Aisin-Warner AW-4 4-speed automatic, used with 4.0 L I6.

[cantab27]

yota box

[Metlic53]

mine jerks on me too, all of mine do, they are just finicky to get out of 4 wheel drive, a few shift from drive to reverse and playing the the 4wd knob (going to and from 4x4 will get it back to 2 wheels.
yours probably has the np231 or np242 transfer case. do you have 4 full time, part time the 4 lo or 4 part time and 4 lo?
if you have 4 full time then its a 242 transfer case.

[jaysXJ]

it has full time

[cantab27]

mines allways been sweet in and out of 4wd ...do it on the move be it slow but...

[Mudderoy]

The NP242 transfer case that gives you full time 4x4 and part time 4x4 has a bit of an issue as they get older. When I take mine out of 4x4 if the level isn't sitting flat then I know it's not out of 4x4. You actually pass through part time 4x4 on the way back to 2wd.

The thing that works for me 100% of the time now is...

On a straight portion of the road, and while slowing down I'll slip the auto to neutral, and around 20 mph or less I'll switch the transfer case lever to 2wd. I'll feel it snap down and I won't be able to push it down any further, in other words, it's not springy to the touch.

Sometimes I'll hear a slight "pop" when I put the transmission back in drive.

I try to find a good long stretch of road that is straight in case I have any problems.

Full time means the front diff and rear diff are NOT locked together. Power is being applied but since they are not locked together you can drive normally on dry surfaces.

Part time means the front and read diffs ARE LOCKED together. So when you make turns on a non slippery surface the inner wheel is turning faster than the rest of the wheels and that jerking of the wheel occurs. This can lead to a damaged transfer case, or other parts in the drive train.

You can put your Jeep in to 4x4 at 40 mph+ I read somewhere 80 mph but people say I'm crazy. They do tell you to let off the gas before putting it into any 4x4 modes.

Now if you want to get into 4wd lo, you will need to come to a full stop, put the transmission in neutral, the move the transfer case to neutral then into 4wd lo. Put the AW4 back in drive and forge ahead. Keep and eye on your rpms! lol

[4.3LXJ]

Just a little further explanation Jordan. Your Jeep has one of two transfer cases available. The first is the NP231 which most XJs have is just a simple 2WD - 4WD - N - 4Lo. You have the NP242 transfer case which also has a full time 4WD option. It is a little confusing to some about the terms part time and full time since whatever position you have the lever in, that is what you have until you change it. But as Tony said, sometimes they can be a little persnickety to shift out. This is due to the design of the shifting mechanism. But the part time option has the front and rear axle locked together. This is the preferable option for low traction situations like mud, rocks etc where you can start spinning tires. The full time option has a differential in there that lets the front and rear axle turn at different speeds while still having power to them. This option is good for times like traveling on slick roads, snow and ice. You have power to all wheels and still not have problems turning sharply on hard surfaces. You can use this option in any situation without problems.

Getting to 2WD from 4WD has the same problems as other transfer cases, even the old school ones. If there is torque on the internals, it won't shift out. This is good in a way so that it won't just pop out of gear on you. But to relieve it, you can try taking you foot off the accelerator while pushing down on the lever or stopping and backing up a little while pushing down on the lever. This reverses the direction of torque on the parts and will allow them to disengage.

[jaysXJ]

thanks a lot, guys. you would think other vehicle makers would make their 4wd systems similar to Jeep's. I was always unhappy with the uselessness of Ford's 4x4 system and what you have to do to properly engage or disengage it. Once again, thank you :)

[Mudderoy]

thanks a lot, guys. you would think other vehicle makers would make their 4wd systems similar to Jeep's. I was always unhappy with the uselessness of Ford's 4x4 system and what you have to do to properly engage or disengage it. Once again, thank you :)

Well there are pluses. For example lock out hubs. On a Jeep if your front tires are turning so is the front diff and front drive shaft. They do make lock out hub kits for the Cherokee but they are pretty pricey.

[Carves]

Getting to 2WD from 4WD has the same problems as other transfer cases, even the old school ones. If there is torque on the internals, it won't shift out. This is good in a way so that it won't just pop out of gear on you. But to relieve it, you can try taking you foot off the accelerator while pushing down on the lever or stopping and backing up a little while pushing down on the lever. This reverses the direction of torque on the parts and will allow them to disengage.


X 2

Foot off the loud pedal ... for a 2wd to 4x4 part-time (4hi), shift on the fly - and back.

I make it a habit to select/deselect, 4x4 full-time (all wheel drive) and 4lo from a stopped/gearbox in neutral, position ... and I dont use D except in 2wd.

... but thats just me and my funny ways .. :D

... and just as with most of my various brands 4x4s Ive had ... a little forward and reversing will "free up" the transfercase.


Might be worthwhile checking that the transfercase gear change linkage is adjusted correctly too. ;)

[XJ Wheeler]

Yep, just in case check the linkage.

And, if my minds not tricking me i believe the top speed for full time is 55 mph. But don't hold me to it.