4WD Problems?

Ok, I want to thank everyone ahead of time and hope this is'nt to stupid of a problem.... I've got a '89 4.0 4WD and the diaphram on the vacuum line to engauge/disengauge 4wd has been slipping and doesn't reallt stay on very well, so i got underneth the car and just ran 1/8" airline tubing that i had left over from a fish tank, bingo works. My question is that I was also hoping that it would fix other problems like when making tight turns the car really doesn't like it at all (in 4WD H)... Is this normal? And sometimes to get it out of 4wd gotta go backwards othertimes its fine. Thanks All

4wheelin' said:

Ok, I want to thank everyone ahead of time and hope this is'nt to stupid of a problem.... I've got a '89 4.0 4WD and the diaphram on the vacuum line to engauge/disengauge 4wd has been slipping and doesn't reallt stay on very well, so i got underneth the car and just ran 1/8" airline tubing that i had left over from a fish tank, bingo works. My question is that I was also hoping that it would fix other problems like when making tight turns the car really doesn't like it at all (in 4WD H)... Is this normal? And sometimes to get it out of 4wd gotta go backwards othertimes its fine. Thanks All

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In tight turns you will get driveline binding which feels like "bucking" when 4WD is engaged. Either cut your turns a bit wider or grit yer teeth & let it happen. I don't believe you have to back up to release the hubs from 4WD, I never had to anyways, the hubs will come out on their own.

I've always had a horrible time getting into and out of 4wd with my '92 xj, driving it in reverse sometimes works but the best thing is to find a patch of gravel or ice and shift it on that. Also make sure your tire pressure is equal on each tire.

I've had problems getting the 4wd to disengage at times. Usually if I mess with the lever a bit it'll go out. I often wondered if it was just the switch for the dash light "part time" that was sticking because sometimes it doesn't feel like it's in 4wd, even the with light on.

I'm glad someone answered your question about the bucking issue on tight turns because I was gonna ask the same thing today. I'm happy it's normal.

I've read here: http://www.naxja.org/forum/showthread.php?t=17476&highlight=np242
that the dash lights don't necessarily mean that you are in or out of 4WD. The shift into and out of 4wd at the T-case is mechanical from the lever, so once you move the lever, you're shifted.

On mine, it won't shift out of 4wd with pressure on the drive line (ie foot on the gas). Foot off the gas and it shift out no problem.

I have a 92 XJ and have no problems getting in or out of 4 wheel drive. THe only problem is that I have no light come on. I have a stupid question however....with 4 high (part time?) engaged I dont go over 45mph. What is the standard maximum speed for being in 4 high (part time?). We get alot of snow covered raods that are driveable at speeds higher than 45mph but I wouldn't if I weren't in 4WD. THe problem is when these all wheel drive vehicles get behind me they get up on my tail.
I want that sticker "Go ahead, pass me. I'll pass you when you need a rescue."

theschwarz1, my manual says any legal speed is okay in 4 High. I've had it up to 65 without any problems...although it still makes me nervous.

I had problems getting my 90 out of 4x. I disovered that the vaccuum module where the vaccuum lines plug into the transfer case was sticking. Took it off and found that the plunger (looks like a metel bearing on the end of it was stuck). Took one that was freed up out of a donor tcase and it worked fine.

I have been wondering if my 4H (Command Track) is engaging or not. I haven't had much use for it lately, but have tried it in the snow. The light comes on, but I can't hear or feel anything different in the velicle. 4L I can definately feel a difference.

Copperhead

1987 Laredo 2Door, 280,000KM, original clutch
1996 Sport, 2wd, 155,000MI

The dash light is activated on the PT tcase models when the front axle is engaged. Some years it is an actual switch on the disco housing, and the earlier years like mine it is a vacumn actuated switch that's up on the PS inner fender. I'd suppose the FT cases 228, 229, 242 all have the switch actually on the tcase itself.
Mike B.

Oh yeah... to answer the original post..... Here's what I tell my wife about how to know what to select in the WJ - 2wd when driving in normal conditions, 4 Full time - can be used all the time when there might be slippery conditions, 4 Part time only if you need to get through some deep snow and there is no dry pavement anywhere within sight, 4 Lo - only for use by me (-:
If running a PT case learn how to pull the lever up and down, only have it pulled up when there is no bare pavement within site, when you come to an intersection to make a turn put it back in 2wd to make the turn.
I go through about 2 sets of ujoints a year (already destroyed 1 set of 760 spicer joints & 1 inner shaft this year) on my plow truck even though I try not to run it anywhere on the road in 4wd, if I left it in 4wd it'd be more like 4 sets of ujoints and a pair of DS ujoints per year.
When you run any at all in pt 4wd on bare pavement here's what wears - axle ujoints & axle shaft yokes, ring & pinion, DS ujoints, and the tcase chain really gets a good beating and stretching.
Mike B