I can not get into 4 wheel drive with my 95 yj jeep wrangler?

Question

i get the low end power and torque but the front wheels dont engage this is vacume driven i belive or is it electric shoul i be looking for a fuse out or something?

Answer 1

There is a Vacuum disconnect on the passenger side axle.

Here is a picture of it:

http://www.cdmfabrication.com/bbpics/disconnect.jpg

There is nothing electrical about it. There is a sensor on the vacuum disconnect itself, but this is only for the 4WD light, if your 4WD light is coming on the disconnect should be working properly.

Basically you have a vacuum switch on the transfer case, when you pull it back into 4WD it feeds vacuum to the disconnect unit and pulls the shift fork over to lock the two piece passenger side axleshaft together.

Here's a good writeup on how it works, how to take it apart, etc:

http://www.cdmfabrication.com/bbb/viewtopic.php?t=4

Basically as you will see from the pictures there are two nipples on the vacuum disconnect, applying vacuum to one moves the shift fork one way, vacuum to the other side moves it back, it should not bleed vacuum between the two. If you don't have a vacuum pump, just flip it over to drain out any water that maybe in the disconnect unit, and actually just suck on the nipples to see if they move. Most of the time is a faulty disconnect unit creating the problem, rarely have I seen the switch on the transfer case go bad.

If it is a vacuum line problem, here is a map of how all the vacuum lines are:

http://www.cdmfabrication.com/bbpics/vacdiagram.jpg

Answer 2

I'm fairly certain(correct me if I'm wrong) that the Yj's 4wd is vaccum actuated. I know it was on both of the Cherokee's that I owned. I had the exact same problem on both of my XJ's. The problem is most likely either a cracked or plugged vaccum line. If you get under the Jeep you should see little colored plastic tubes running down to the front axle. Check to see if any are broken or cracked. If so then all you have to do is cut the tube and find some cheap rubber hosing that you can use to reconnect the tubing where it was damaged. If you don't notice any cracks then you can try running a wire through the tubing(something like a small bit of dirt could be plugging it up). I had a cracked line on my 89 cherokee and a plugged line on my 84 cherokee; both problems were solved in 5 minutes with these simple solutions. I hope this is helpful to you.

Answer 3

The front axle is vacuum actuated. Check for a vacuum leak and the switch mounted on the transfer case.

Answer 4

On the passenger side of the front axle is a vacuum line that acuates the front driveline, check to make sure it is correctly attached, and not damaged.

Answer 5

Does your jeep have manual locking hubs in front? look at them and if you have extended hubs in the center of the wheels look for arrows that say lock and unlock. If not that the transfer case may be electricaly operated and look for a fuse in your fuse box for a blown fuse. I thought they came with a manual transfer case, but you never know, just some stuff to try.