Spacecowboy

Hello chaps, I haven't got round to buying an owners manual for my XJ yet and I was wondering if someone can tell me when you should the 3 drive options I have. I use 2WD at the moment as I am driving on dry clear and fast roads. I have used it on wet/snow covered roads in 4WD, but haven't had to use the low ratio option yet.

The main questions I have about it is:
When should part-time drive be used?
What would be the ideal conditions and max speed for each drive mode?
Is it right to have the car rolling slowly when changing drive mode on the TC and would the main gearbox have to be in Nuetral do it ?

I know these might sound trivial, but I am getting quite attached to the old girl and don't want to screw up my drivetrain.

00jeepXJ

welcome to CF...

4wd that you have should be used on slippery surfaces until you are onto or moving onto a surface in which you have traction. The transfer case can be engaged and disengaged while moving as speeds less then 30 mph. 4 wheel low should be used when you can't get out of a spot that you are in with 4 wheel high. Low range is really good if you are pulling something out while on loose ground.

As for speed I personally don't like to go over 45 with 4wd high just to save wear and tear on the transfer case and driveline as well as saving some fuel. Low range is pretty much limited to under 25 mph as it's geared really low and you just will end up spinning the rpm's pretty high to get anything more.

You should never try to engage low range while driving... lots of bad noise will occur and damage might also. To get into low it is best if you come to a complete stop and then shift into N on the transmission, then move into Low. Once in low place it back into gear and go.

Hopefully this helps and others will chime in with there opinions and ideas on this subject for you.

RK1911

Just to paraphrase the Jeep Cherokee owners manual for XJs equipped with the NP231 transfer case; "You can engage 4 HI at any legal forward speed." My 231 will engage just fine on the fly, and I have driven at 45+ in packed, dry snow. I will however state that you are best off driving in 4WD only on slippery surfaces. I also will agree with 00jeepXJ on the use of 4LO. Don't shift into 4LO unless you are at a dead stop, and have let the transmission/transfer case spin down to 0 RPM, unless you want to hear a lot of ugly noises.

Spacecowboy

Thanks guys. Thats pretty much how I thought the car should be driven. I am still unsure about the part-time 4WD though. I assume that that mode is for off-road use only and at pretty low speed as well ?