t88itsagpthing

88 Cherokee - the OEM Z shift linkage stopped working so I replaced it with a direct link using threaded rod and female rod ends, I got the idea from http://www.bsfab.net/?p=26. While adjusting the linkage I found that the front wheels weren't engaging. The drive shaft to the front differential is turning when I shift into 4H or 4L so it appears the problem may be within the differential, any thoughts on this or has anyone ran into this problem? There is a hose connected at the top, is this for vacuum and could this be the issue?

Also about 7 years ago I had the Peugeot transmission replaced with another Peugeot tranny. There is a hose at the top of the transmission near the shift lever, I just found that the other end is hanging lose with a metal L shaped fitting in it. What does the lose end hook up to? I found the same type of fitting on the driver side towards the top of the transfer case (NP231) with no hose on it, does the hose go on this fitting?

sycoglitch

88 xj IIRC uses a vacuum and the shift fork to shift. So your issue isn't the axle since it'll always spin no matter what

t88itsagpthing

Thanks for your response, I'm not quite following you. I have it on jack stands and when I put it in 1st gear and the transfer case in 2H the drive shaft doesn't turn which is normal. When I put the TC in 4H or 4L the drive shaft turns but I don't see the wheels turning. Shouldn't the drivers side at least be turning?

aroundincircles

vacuum line connects to the front axle to loc it. should be plenty of info on renix 4x4 system if you google it.

t88itsagpthing

So this is used for the vacuum on the axle to engage the sleeve that connects the two axles? If so then I don't need to worry about it since I switched to the Posi-lok system.

t88itsagpthing

sycoglitch and aroundindircles thanks for your help, the four wheel drive is working with no problems, I found a forum that said to have only one front wheel off the ground and when you try to turn the wheel it shouldn't turn, which is what I found. As for the hose I'm still looking into it.

DFlintstone

Actually in 2WD the front drive line is not driven. (even with command track, and the vacuum disco). "posy lock system?" So you locked your Disco? fine.

Both the tranny and T-case have vent tubes. Nothing fancy, they just come up high enough to not end up under water, (usually), like on the firewall, and have some sort of filter to keep crud out.

sycoglitch

I remember after i was reading afterwards. Forgot the dinosaurs were different that the solid 1piece axles of the after renix years.

DFlintstone

Yes, at least one (or both) should turn. If it's only one just holding it should make the other turn. There is a vacuum diagram for the disco in my signature. There are three to it because when the fork actually moves over, it shoots vacuum back to that blue switch there near the expansion bottle to tell you the fork has actually moved over.

F1Addict

The tube on the driver's side is a vent. As Flintstone said, it's usually routed up into the engine bay where it terminates near the firewall to prevent water from entering the tube. The vacuum disco is on the back of the axle on the passenger side but if you've installed a Posi-Lok, that system is now mechanical.

DFlintstone

I don't mind having my disco function. They re-designed the early forks that would break. I have a loose zip-tie on that rubber block so any little thing can't knock it off. (with the vacuum lines). So most of the time my front drive line, the carrage, the pinion bearing, T-Case bearings, some U-joints, all of that is turning 1/2 the speed it would with a solid axle. The newer saved Jeep money. The earlier saves me money!

t88itsagpthing

Thanks for your response on the vacuum tubes. The transmission one was just hanging down so I'll fasten it onto the firewall. I'll have to pick up a tube for the transfer case fitting and route it up higher also.

As for the 4WD in 2WD the shaft didn't turn, but did in 4H or 4L this is how it should work. Once I had the back wheels and passenger side wheel on the ground and the transfer case in 4H, when I tried to turn the driver side wheel I could see the drive shaft try to turn also, which indicated that the 4WD is working as designed. I did switch to the Posi-lok so the vacuum lines are disconnected for that part.

Also if you guys have the Z shift linkage and have to replace parts, you should check out the link I put in my first post. My jeep is stock and the setup works great, I did extend the length on my shift lever instead of getting the TJ's lever.

DFlintstone

Sounds like you are OK.."posy", would mean your differential is locked. It would bind, and "chirp" doing a tight turn on asphalt since the outer wheel is covering more ground then the inner. "limited slip" diffs have clutches that make it drive both wheels, even if one is off the ground. It sounds like you locked your disco, (the vacuum disconnect on the Right front axle on command track). That's not Pozzy, or limited slip or anything like that. That's fine. Btw, I think there is a way to route a vacuum line from the Vac switch on the transfer case to that blue vacuum switch on the fender there near the expansion bottle to have a light come on when you put it in 4WD.

Waz thinking, a guy could have his spiders welded and use the Disco for full lock pozy...

t88itsagpthing

I could feel the 4L working when I tried to drive with it in gear so every thing is fine. I'll have to do the turn test for peace of mind. Thanks for the transfer case tube routing info, I'll check that out. I may not get the light to work though due to electrical issues. I had some kind of short about 3 years that left the left half of my fuse block with no power. My wipers, I believe blinkers and one other item weren't working, so I used jumpers with inline fuses and jumped the power from the right side of the fuse block to the left side to get things working. I found some lose connections under the dash board and a ground wire that was lose that may have been part of the issue. I haven't replaced the fuse block since it looks like a pain to do.

DFlintstone

Is it a manual trans? If so you might want to look for a replacement fuse block. You can just apply any vacuum to the switch and see if the light comes on. Just grab it at the FPR or somewhere to test the switch if you like.