I had some rain and used the opportunity to test if my 4WD still works. I remember learning there is no real reason to use 4Lo foir road driving. I stopped and pulled the lever to 4Hi. I heard the front diff engage, the car was louder, and I felt the difference in power delivery to the wheels.

To disconnect, I stopped and put it into 2WD. It was still in 4WD. So, I remembered that you need to go in reverse to disengage. I went in reverse and then forward, and it was back in 2WD. This is correct?

Does the front diff (transfer case?) just sit disengaged all year old in 2WD?
I wonder if I should change that fluid before winter.

 

Key points:

- You can shift from 2HI to 4HI while moving at any speed (and from 4HI to 2HI). Just let off the throttle and shift away. I wouldn't recommend doing it over 60 mph, but I've heard others have tried higher and had no problems.

- DO NOT OPERATE IN PART-TIME 4HI UNLESS THE SURFACE IS SLIPPERY. Snow, gravel, sand, dirt, etc. are all slippery. Wet pavement is NOT. If you have the full-time option, you can use that on any surface.

- The only reason I can think of using 4LO on road is getting yourself out of a situation where you're stuck. Like if you go into a muddy ditch or snowy embankment.

 

This is correct.

The owner's manual says you can shift into 4HI on the fly at up to 55mph. I've heard that number is arbitrary for legality's sake, and I've safely shifted into 4HI at 70mph. It is possible that that could cause problems, but I haven't experienced any.

Your second two points are spot on. DO NOT use part time 4WD on pavement unless there's ice or a good bit of snow on it. Engaging on a surface that has traction is a good way to do serious damage to your transfer case.

4LO shouldn't be used on the road or at speeds above 20-25mph max. Like 4HI, it shouldn't be used on a dry surface.

 

Driven my jeep on dry surfaces plenty of times in 4 hi and 4 low.

 

Congrats...? By dry surfaces they mean anything that's dry and has traction... like a road, or driveway. Not off-road.

 

I shift into 4H all the time here while driving all the way up to 80 mph. I just put it in neutral, put it in 4h and put it back in D. I have yet to have any problem as well. I have it in 4h quite a bit while going down the interstate in the winter- some spots dry, some spots icy. Can you explain to me why you should not have it on when you are on dry? (part time) I can understand when you are in town and making a lot of turns etc. but what about the interstate? I have ran all of my XJs like that (dry with snow/ice in spots) down the interstate for miles and miles, year after year with no problems.

 

I know about axle binding/driveline wind up but all that only happens when making a pretty significant turn. In a fairly straight line down the interstate you should be fine right? Black Ice is no fun to hit with 4hi off. I guess maybey nothing happened because there is always snow/ice on the road in the winter here lol.

 

I think its cruiser54 who would only shift in 4hi doing 80+, anything less was just a waste of his time

I have NITTO Terra Graplers on my DD and they SUCK on wet pavement.... I do not look forward driving it on wet pavement!!!!!

more of a reason I need to get my XJ done.......

 

Say, everyone--
I have had five Jeeps over many years but until now with manual transmissions. So with my newly accuired secondhand XJ selec-trac, can I use 4LO parttime off road gravel and mud but on a surface that occasionally has couple hundred yards of hard rock ledges? Sp far, so gppd -- but all these warnings about my transfer case.... well.
Rgds, Kap

 

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".

 

Drove for an hour in the snow today.
The XJ performed nicely.

I was able to shift into 4Hi at various speeds, and the shift was instant.

I was able to shift back to 2WD on the fly, as well.
After putting it into 2WD, it would still be in 4Hi, and after a minute or so, there would be a loud CLUNK and it would be back in 2WD.

 

Start of the snow season: Select 4 FT
Spring: Select 2WD

end

 

Just curious, how well do XJ's perform in the snow in 2wd?

How nasty does it have to get before you HAVE to go 4wd?

 

Depends entirely on your tires.

 

They suck in 2wd..........great in 4wd.

Then again, anything rear wheel drive with limited weight in the rear sucks in the snow.