Jeep Wrangler Forum

Jeep Wrangler Forum (http://www.wranglerforum.com/)
-   YJ Tech Forum (http://www.wranglerforum.com/f218/)
-   -   4WD not working (http://www.wranglerforum.com/f218/4wd-not-working-294793.html)

dandirkse 09-15-2013 07:28 PM

4WD not working
 
I am new to the YJ scene, and I am having an issue with the 4wd. I know I have a vacuum leak, and I think I know where it is. I found the lines from the transfer case and traced them to the battery box area, where they are cut through. I found two lines right above them coming out of the firewall that have vacuum, but I don't know which line is which. Can somebody point me in the right direction, as both lines are black in color, and I don't want to hook them up wrong. It's hunting season, and it sure would be nice to take my Jeep offroad to some good spots this year. Any help would be appreciated.

harleydragon 09-15-2013 07:58 PM

if it has factory lines,the black hose hooks to the low vertical port on the front axle and goes to a vacuum switch on the firewall,under the battery..all this black hose does is turn the 4 wheel drive idiot light on the dash on ..

dandirkse 09-15-2013 08:10 PM

Okay but there are two of them there. Do I match left to left and right to right?

AllMudd 09-15-2013 08:20 PM

I am not sure here, but I would try to match the ends like a puzzle. If one is cut like a "z" and the other is like this "/" then it's easy. But if they both are cut the same you might have to do trial and error. Hook them up how you think they go and try it. If it does not work swap them and try again.

dandirkse 09-15-2013 08:32 PM

Good idea. I'll try that in the morning. Thanks for the help.

steve1981 09-15-2013 09:14 PM

the vacuum hose does more than cut a light on. it moves the fork in the shift motor housing which slides the coupler over the gap between the passenger axle shaft and the intermediate shaft which gives you drive to both front wheels.

harleydragon 09-16-2013 05:32 AM

Quote:

Originally Posted by steve1981 (Post 4603417)
the vacuum hose does more than cut a light on. it moves the fork in the shift motor housing which slides the coupler over the gap between the passenger axle shaft and the intermediate shaft which gives you drive to both front wheels.

thats what the yellow line does

dandirkse 09-16-2013 05:42 AM

There is not a yellow line. They are both black, which I stated in my first post. If they were black and yellow, this would have been a non issue. with both lines being black in color, I am going to try and match the cut ends.

harleydragon 09-16-2013 05:49 AM

yellow line goes from the transfer case to the front axle..I believe you are on the right track trying to match the cuts as suggested earlier by mudd

dandirkse 09-16-2013 06:04 AM

Thanks Harley. Again, all lines are black...I think the guy I bought this jeep from did a lot of work in it and did not do it well. I am going to try Mud's idea as soon as it gets a little bit more light outside. I really do appreciate all the help from everybody.

harleydragon 09-16-2013 06:17 AM

Quote:

Originally Posted by dandirkse (Post 4609137)
Thanks Harley. Again, all lines are black...I think the guy I bought this jeep from did a lot of work in it and did not do it well. I am going to try Mud's idea as soon as it gets a little bit more light outside. I really do appreciate all the help from everybody.

with age all those lines begin to look black..

bigb996 09-16-2013 12:41 PM

I would do yourself a favor and switch to a posi lock system and you will have a guarunteed to work system everytime

harleydragon 09-16-2013 12:57 PM

Quote:

Originally Posted by bigb996 (Post 4616497)
I would do yourself a favor and switch to a posi lock system and you will have a guarunteed to work system everytime

I have had good luck with the factory setup once I got all the previous owners bugs out of them

dandirkse 09-16-2013 03:03 PM

I did get it figured out but now the 4wd is active all the time. It won't let me shift it down to 2h. Any suggestions?

harleydragon 09-16-2013 03:17 PM

Quote:

Originally Posted by dandirkse (Post 4619769)
I did get it figured out but now the 4wd is active all the time. It won't let me shift it down to 2h. Any suggestions?

the vacuum switch that screws onto the transfer case often goes bad..you can find them on ebay for about 10 bucks..you could have another hose that is broken or pinched.those are the 2 most common problems that I find.here is what the different color hoses do
red-vacuum from engine to transfer case switch
green-vacuum from t-case switch to front axle to disengage 4x4
yellow-vacuum from t-case switch to front axle to engage 4x4
blue-connects to t-case switch and then just has a small filter on the other end ( connects to nothing)..this allows for releasing the vacuum on the line not being used
black-from axle to vacuum switch..this controls the idiot light

wasomma 09-16-2013 06:51 PM

Harley has some good suggestions there, he's been spot on this whole thread about repairing the stock system.

If you decide you want to get away from the vacuum system as a whole there is the posilok option which was mentioned before:

Posi-Lok PSL900 - 4x4 Posi-Lok for 84-95 Jeep® Wrangler YJ, Cherokee XJ & Comanche MJ - Quadratec

dandirkse 09-16-2013 07:55 PM

Quote:

Originally Posted by wasomma (Post 4625409)
Harley has some good suggestions there, he's been spot on this whole thread about repairing the stock system.

If you decide you want to get away from the vacuum system as a whole there is the posilok option which was mentioned before:

Posi-Lok PSL900 - 4x4 Posi-Lok for 84-95 Jeep® Wrangler YJ, Cherokee XJ & Comanche MJ - Quadratec

I appreciate all the help by all of you. Harley, your breakdown is awesome. That should help track it down. I will go the posilock way in the future, but right now I kinda want to keep her stock.

Wombat Ranger 09-16-2013 11:51 PM

I personally hate vacuum operated anything, but since I hate spending money even more, I repaired my vacuum system and plugged the source line right into the side of the carb after I removed all the smog crap. I have had zero troubles with the axle engagement since. It's not a bad system when properly set up, but lockout hubs and one piece axleshafts woulda been better...


All times are GMT -5. The time now is 02:59 AM.