4x4 help

[JeepNOFEAR]

I just got back from a trail about 30 minutes ago. I found out my 4 wheel drive isn't working. Didn't stop me, it just took longer for me to get up stuff then everyone else.

I figured I would go ahead and ask to see what some possible problems would be. Thank a lot. [img]smile.gif[/img]

[FSJ Thing]

Which t-case you got again?

[JeepNOFEAR]

oh sorry about that, might help if I tell yall. its 401/th400/Q/T

[JeepNOFEAR]

oh and it has locking hubs.

[Stuka]

Ok, so you have a QT with a part time kit? Did you turn the nob inside the gove box to be in 4wd mode? If you have a PT kit, just locking the hubs wont put you in 4WD. Although if you are just running in e-drive, than locking the hubs should have done this.

EDIT: oh yeah, if the nob was turned, and it didnt work, than it most likely is a vacuum leak, or the modulator isnt working right.

[ December 09, 2005, 10:32 PM: Message edited by: Stuka ]

[FSJ Thing]

Alright, a QT with locking hubs, I'm going to bet by the fact that it moves that it has a part-time kit installed, which isn't uncommon.

So you lock in your hubs and flip the switch in the glovebox to "emergency drive" but the front axle doesn't come to life?

1) When you flip the switch, did you hear a short and quiet "shishhhh" noise? If you did hear it, did it last two seconds or so, or was it a lot longer?
If you heard the 2ish second shishhh then the vacuum system is fine and their is probably something jamming the linkage in the tcase.
If you heard the shishhh but it kept going "shhhhhhhhhhhhhhhhhhh" then you probably have a busted vacuum motor on the tcase or more likely, a torn vac line going to the tcase.
If you didn't hear anything remotely like a shishhh then the vacuum line going to the engine or vac ball is plugged or the switch is broke.

If I'm wrong, or not thinking right, someone should correct me soon...

[JeepNOFEAR]

I have to go to work now so I can't mess with it till I get home tonight, but here is some more info.

When I bought the Jeep the tranny was gone. I took the tranny and transfer case out of another Jeep Cherokee in my yard and stuck it in this one. I never drove the donor Jeep so I don't know anything about it, but it also has locking hubs. Both Jeeps are the same year and have the same drivetrain, they even have similar camo paint, except one has a 360 and the other a 401.

The owner before me had made his own glove box, for the trail Jeep not the donor, and made a little thing for the switch also. It didn't have the green and red plate saying normally drive/emergancy drive.

I went and looked at the donor Jeep and it looks like I've been running my trail Jeep in emergancy drive since I got it because the switch is turned to the right. What kind of problems could this cause even thou my hubs were unlocked?

Thanks for the responses and I'll try everything yall said when I get home.

[JeepNOFEAR]

How far does the knob turn? Does it turn from say 9 oclock to 3 oclock or all the way around?

[JeepNOFEAR]

I found out one of the lines wasn't hooked up and I hooked it back up, still didn't work. I traced all the lines and they are all hooked up. I switch the lines on the transfer case to see if that would work, it didn't. How powerful is the suckin in the vacuum lines, I think I feel it but its not really strong.

Also another question on the knob, which way is emergancy drive, drivers side or passengers?

The passenger side hub is different from the drivers side. The passenger side switches by going from 2 oclock to 5 oclock, it doesn't spin around to lock like the drivers side.

[ December 10, 2005, 07:22 PM: Message edited by: JeepNOFEAR ]

[JeepNOFEAR]

I'm almost ready to swap in a dana 20, like in my blue Jeep.

Stuka: the modulator, what is that? Is that the thing on the transfercase?

FSJ Thing: The SHHHHHH noise, is it loud or do you have to concentrate hard?

The vac ball where and what is that?

Is the vac motor the thing on the transfer case?

I have 3 Jeep manuals, chilton, haynes, and a 1976 Jeep manual and I can't find anything in them about this vacuum system.

[ December 12, 2005, 03:33 PM: Message edited by: JeepNOFEAR ]

[JeepNOFEAR]

I found out I'm not getting any vacuum. I hooked an air nozle to the middle stub on the switch and it locked right into 4 wheel drive. I replaced the line from the middle stub to the engine and it still didn't fix it. Would the problem be the thing on the intake manifold?

[JeepNOFEAR]

Do yall think an air ride suspension compressor would work to power the vacuum system? Do I need a constant flow of air to keep it in emergancy drive or could I turn the compressor off?

I'd put a tank in the Jeep so I could do other things too.

[Stuka]

My guess is you are connected to a CTO switch or something on the intake (temperature controlled switch). Find a spot one of the vacuum ports comming from the intake that always has vacuum (pull a line off while its running to see if you have vacuum, rev the engine to make sure it always has vacuum). And connect it here if it was just capped off, or put in a T. Then route this line to your e-drive switch, then the switch to the t-case.

The vacuum ball is on the firewall (right in the middle, black round ball about 5" in diameter). And actually, to correct myself, the t-case switch should come off of this. That way when vacuum drops for a few moments when you hit the gas, your t-case doesnt pop out then back into e-drive.

[JeepNOFEAR]

Thanks for all the help stuka. I got it working, I just need to buy some connectors to hook up that ball on the firewall.