Is my differential not engaging/having trouble?

So I have a small problem (well quite possibly a big one) that I've had with my Jeep since I got it some 2 weeks ago.

Examples:
1) The first time was I was on a hill on an off-road trail and wanted to back up it, so I put it in reverse while in part-time 4wd and my engine reved pretty high till I hear a saw type sound (grinding) so I stopped. When part time didnt work I tried putting it into 4wd full time, same thing happen. Lastly I parked it on a block of wood and turned it off, trying to find a way out, then I decided to try 4wd low (my first time "4wheeling" gime a break) and it reved but then took right up the hill, no problem.

2) Another problem I've had is when I got to put my Jeep up on some wood/plastic ramps. I put the Jeep into 4wd full and roll up to both the blocks and plastic (plastic up front, wood blocks that gradually get bigger in rear) and would roll up that. But then when I roll back out after I'm done doing w/e I'm doing, the steering gets stiff, and it feels like the brakes are on. Also the engine revs high and doesnt go very far very fast. And usually if I turn it off and keep trying to change the driveline around it will work.

So my question is, what the heck is going on!? Best I can tell with my little knowledge is the differential is slipping or isnt engaging correctly. I've had this problem with the car being slow and an obvious problem (as described) several times, but only when I change from 2WD to something else (any of my options it happens...) and if it means anything, even if I'm not in part time, sometimes the light will come on for part when I go to Full and back to 2wd.

I have an '89 Jeep Cherokee Limited with the NP242 if that helps. (Well, I think it's the NP242...2WD, 4WD Part, 4WD Full, N, 4WD Low)

P.S. YES, I do put the car in Neutral before changing to any driveline.

:banghead:

Could be a vaccum issue with the engagement with your front axle, also when go to engage are you sure you are pulling it all the way?

-Alex

just a guess here, but maybe check your vacuum disconnect on the front axle.....it might not be engaging properly or just partially. i know i have to redo the vacuum lines on mine because they just slip right off and i get no 4wd(its zap strapped on right now).

edit: beat me

oh yeah, I pull it all the way...I wiggle it around to make sure its in.

What can I do to fix the vaccum? I know my dad bought all new vaccum hoses for up top at the engine cause those were leaking...

well, i would at least check the vacuum lines going to the axle from the transfer case(they run to the passenger side of the axle). if they are damaged or loose in any way, replace them. any leaks would cause problems. now, apparently the diaphram can go bad pretty easy as well....but i dont know how to test that.

The 242 doesn't use an axle disconnect. The frt driveshaft is always turning in 4wheel or not. You have to "shift on the fly" to get in and out of part time and full time. 4-lo is the only one you can just pull in standing still.

It's possible the linkage is off and he's actually in 4wd part time when the shifter is in the 4wd full time selection.

And it might not be fully engaged in 4wd part time when the shifter is in the part time position, hence the grinding you heard.

Blaine B. said:

It's possible the linkage is off and he's actually in 4wd part time when the shifter is in the 4wd full time selection.

And it might not be fully engaged in 4wd part time when the shifter is in the part time position, hence the grinding you heard.

Click to expand...

That's what I'm thinking...I just dont know how to check it.

Try putting it in 4 wheel while moving. The 89 owners manual says to do so. I don't know when they changed it maybe with 231.

You shouldn't need anything but part-time 4hi for offroad and D.