What I need is an overview of how the 4WD works on my 01 Sport..

I assume the hubs are automatic since there is no way to lock/unlock them?
How do they work ??

When I go into 4-High the dash indicator says "Part Time" Does this mean I need to be in 4-Low to get the axles to lockup ??

I have heard talk of some type of vaccuum motor related to the 4WD what does this do ??

Any information will be helpfull in me understanding how this works...

Thanks

Matt

 

read your drivers side visor

 

Well I wanted to get a bit more technical than that Dude !



Matt

 

Do you have a part time and a full time option on your t-case??

 

the visor is a good learning tool...


but...

they are automatic hubs

part time means dont drive on dry pavement with it.

full time you can drive all the time on it.

 

Nope.
Just the 4-high 4-low and 2-high select....I read something in the owners manual about this but it made no sense.
When I go to 4-high a "Part Time" light comes on on the dash. I think when in 4-low the axles are locked,because the manual does say not to drive on dry pavement when in 4-low???

 

What part is vaccuum operated in the 4wd mode ?

 

Yes they are. You have an NP231 t-case. You can engage 4 high at any speed under 55, just pull it in and it should go. Low needs a complete stop, tranny in neutral, then pull it in and it should go. To take it out, reverse the steps, and back up a little, but it's been my experience that every vehicle likes a certain sequence of events, you have to find what yours likes. If you need more help or info send me a message and I can explain in more detail. HTH!! Laters!!

 

THANKS !!

I have noticed that it has to be stopped and in "N" before it will go to 4-low.

So the only real difference in 4-low and 4-high is the higher RPMs, No difference in operation of the 4wd ??

 

That's right, 4lo just changes the gear ratio and puts you into a "crawl mode".

 

For a 2000 what is vacuum operated is the lock up for the front axle. The hubs are all time, so when driving in 2wd your front drive shaft will still turn a little due to the shafts rotating, its normal, it helps the gear oil still flow around everything, etc.

I know "lock up for the front axle" isn't the right term for the goofy part, but I can't remember what the goofy thing is called :P

 

The vacuum engages the front hubs. If this breaks, no 4WD for you (happened to me, no fun). Nice thing about 4wd, is if your park (auto) or e-brake (manual) fails, you can just stop it in gear with 4wd on and it'll keep you from rolling away.

 

OK !! That is what I was thinking but was not sure..

I seen on 4WD's site they have a cable that replaces the vaccuum unit, So you can manually shift it from inside the truck..

 

Not all Jeep Cherokees have the vacuum disconnect mentioned above. You can determine if you have it by looking at the right (passenger) side axle tube under your Jeep. If the tube is just a horizontal cylinder then you do NOT have a disco axle. If you see a bump and a vacuum line then you have a disco axle.

 

Thanks I'll look at that this evening !!..