no vacuum at front diff? jeep stuck in woods =/
Thread Starter
Seasoned Member
Joined: Jan 2010
Posts: 251
Likes: 0
From: JERSEY ALL DAY
Year: 1989
Model: Cherokee
Engine: 4.0L
My jeep is in the woods right now stuck in 2 wheel drive 
There is almost 3 feet of snow here in the north east and when i needed 4 wheel, it wouldnt work. Its still snowing we were all having fun in the snow i was drifting in 2 wheel thru trees and got it stuck in a really deep snow drift, and dont have 4x4. It worked fine this morning.
There are 3 vacuum lines on the diff theyre all clear and connected but theres no vacuum down there. Why would i get no vacuum to all 3 lines? Lines seem ok and they go right to the top by the canister but i cant see where they go up top. Is there a valve that activates the vacuum to the front diff that could be sticking?

There is almost 3 feet of snow here in the north east and when i needed 4 wheel, it wouldnt work. Its still snowing we were all having fun in the snow i was drifting in 2 wheel thru trees and got it stuck in a really deep snow drift, and dont have 4x4. It worked fine this morning.
There are 3 vacuum lines on the diff theyre all clear and connected but theres no vacuum down there. Why would i get no vacuum to all 3 lines? Lines seem ok and they go right to the top by the canister but i cant see where they go up top. Is there a valve that activates the vacuum to the front diff that could be sticking?
CF Veteran
Joined: Aug 2008
Posts: 6,588
Likes: 495
From: Chico, CA
Year: 1986
Model: Cherokee
Engine: 4.3L with headers and full 3" exhaust system
The valve is on the tcase. Does your heater work right. If not and it is stuck in defrost, then you have no vacuum to the whole system. You will have a broken hose or something. Also make sure you have vacuum at the reservoir. They can break or crack. If so, bypass it to get home. At the disconnect, you should only have vacuum to one line at a time, yellow or white depending on what the switch calls for. Good luck
Thread Starter
Seasoned Member
Joined: Jan 2010
Posts: 251
Likes: 0
From: JERSEY ALL DAY
Year: 1989
Model: Cherokee
Engine: 4.0L
I'm located in Jersey near Trenton. Where is the vacuum reservoir? I think theres one under the hood and one under the bumper i wanna get it out in one trip and mess with it more here. HVAC controls work, it switches from defroster, floor, vent, anywhere i want to...I got good vacuum going to that. There is no audible vacuum leak.
My speedo doesnt work idk if the speedo gear on the Tcase and the valve for the front diff engaging have anything to do with each other
update:got it out we all shoveled it out its back at my house now
My speedo doesnt work idk if the speedo gear on the Tcase and the valve for the front diff engaging have anything to do with each other
update:got it out we all shoveled it out its back at my house now
well this happened to mine also. It decided to crack all the vac lines off of the t case back where the valve goes into it i think the red hose going back there is the source. I could be wrong if you can get to the end of the hoses from under the hood you could try hooking the vac off of another source like pull the line off of the cruise and hook it up to the green or yellow line that goes down to the front axle. that might work for an emergency situation but i dont know how buried you are if you can get under there you could just hook up a hose to vac canister and put the t case in 2wd and spin the front drive shaft with the vac source hooked up and if it locks in you wont be able to turn the front shaft, then just pull t case in 4wd and leave the vac hooked up until you get out and home to check into it sorry for the rambling but it worked for me
Trending Topics
Thread Starter
Seasoned Member
Joined: Jan 2010
Posts: 251
Likes: 0
From: JERSEY ALL DAY
Year: 1989
Model: Cherokee
Engine: 4.0L
i know its a vacuum issue. im currently looking for a vacuum diagram. stupidest thing ive ever seen is vacuum lines on my diff. why in the world would they do that
Last edited by 88GTBlack; Feb 11, 2010 at 12:31 AM.
Thread Starter
Seasoned Member
Joined: Jan 2010
Posts: 251
Likes: 0
From: JERSEY ALL DAY
Year: 1989
Model: Cherokee
Engine: 4.0L
all vacuum lines appear alright I believe the valve isnt working on the T case. Whats that valve called where all the lines plug in? and how much is part going to run me? Im pissed and the manual cable actuators are like 200$ its a friggin cable with a lever!!!
Im pissed
theres 3 feet of snow i have work tomorow and im 1 wheel peelin and i got stuck in my driveway on 2 inches of snow completely shoveled cuz 2wd stinks and open diff dana sucks even more
Im pissed
theres 3 feet of snow i have work tomorow and im 1 wheel peelin and i got stuck in my driveway on 2 inches of snow completely shoveled cuz 2wd stinks and open diff dana sucks even more
Member
Joined: Jul 2009
Posts: 216
Likes: 0
From: Seattle, Wa
Year: 1998
Model: Cherokee
Engine: 4.0 HO
whichever wheel is spinning take the Ebrake cable off the opposite side drum from the Y link and lock down the spinning side and get some power to that other wheel? Have a friend with a 2wd Datsun truck with 2 Ebrake levers for that reason.
Also dont know if this could help I had 4wd problems with my jeep after it had been sitting a few days in below freezing temps because the moisture in the vac lines froze. After letting it run for a good 30 min or so they defrosted and the 4wd worked again.
Also dont know if this could help I had 4wd problems with my jeep after it had been sitting a few days in below freezing temps because the moisture in the vac lines froze. After letting it run for a good 30 min or so they defrosted and the 4wd worked again.
CF Veteran
Joined: Apr 2009
Posts: 1,109
Likes: 3
From: Austin, Texas
Year: 1991
Engine: 4.0 I-6 H.O.
pull out the motor, then take the e-clips off the shaft, force the shift fork into the engaged position, then put the e-clips back on that will hold the shift fork into the engaged position, this will keep your front axle locked up, and you can limp home.
Good luck
Good luck
CF Veteran
Joined: Nov 2008
Posts: 7,874
Likes: 100
From: Northern Ontario, Canada
Year: 1990, 1999, 2000
Model: Cherokee
Engine: 4.0
well, if you're gonna go through all that work, just simply remove the vac motor and slide the sleeve over the shafts, then just use a hose clamp and tighten it against the sleeve holding it engaged, then just bolt the vac motor back up. you can even run like that for years, trouble free.
i bought my t case vac switch at carquest and nobody could find it in the computer so i walked up the motormite help board and just grabbed it it was under 20.00 i will give you the info on the package it says HELP transfer case switch part #49314 it took about 10 min to change good luck


