blueyes1983

Hi All!
I'm brand new to this forum, and could use some advice/help. This past summer I bought a '87 Cherokee Pioneer (2.5L, AT, Select-Trac). It's been my daily driver ever since, and I've put on about 8000 miles without any problems. When I bought it I wanted to check to see that the 4wd was working, but I didn't really know how to test it. I found a dirt/gravel lot and I pulled the lever up into 4H, and the little light on the dash board came on saying that I was in 4wd. I did a little bit of "tearing around" in both 2wd and 4wd, and I could kinda tell that there was a difference. So, I assumed at that time that the 4wd system was working.
I didn't put it in 4wd again the rest of summer, and fall (no need to). Now, it's winter, and we here in the Midwest are getting snow just about every other day. I had a snowy drive to work yesterday morning, so I put it into 4H (engaging the 4wd for the first time since the week I bought the Jeep). The first thing I noticed, was the little dash light did NOT come on. As I was driving it didn't really seem like I was in 4wd, the back end would start swinging out if I gave it any extra gas. AND, it really wasn't going through the snow very well.
When I got home I jacked up my Jeep and put it on jackstands. I then started her up, and put it in drive, checking to see which wheels were spinning (both rear wheels were spinning, but not either of the fronts). I put it back into 2H, and again both rears were spinning. I put it into 4h again, still just the rears spinning. I then put it into 4L, and yet again, just the rears were spinning. Why aren't my front wheels spinning if I'm in 4wd? Why isn't the dash light on anymore when I'm in 4wd?
I did look underneath when I had it up on stands and I was in Drive. When I was in 4H or 4L the short driveshaft that goes up to the front axle (or whatever it's called) was spinning. When I was in 2H, obviously it wasn't spinning. So, when I put it into 4H or 4L, it is engaging the driveshaft, but it isn't driving the wheels.

I consider myself pretty mechanical (for a girl anyway). I'm the only girl I know who does her own oil changes, and other maintenance. What can I say; I was a tomboy, and my Dad was a Mechanic so he wanted his daughter to know about cars. BUT, I'm completely lost when it comes to 4wd stuff. This is my first 4wd, and I'll admit I'm pretty clueless about it. If I had the money. I'd just bring it into a shop, and have it fixed. but then again, If I had the money I probably wouldn't be driving a 22 year old Cherokee.

Anyone have any suggestions that I could check? Is there something electrical that engages the front wheels that isn't working so my dash light isn't coming on either? Why is it that the short driveshaft is spinning to the front axle (differential?), but the front wheels aren't moving?
Please let me know if you have any advice.


Jamie

BowtieGuy3

Welcome to CF from Chicago!!!

Well I guess first thing is first....
Do you have a disconnect axle? You can tell by a weird little hump on the right front axle tube. If so, the little vacuum actuator might be shot (seems to be a problem this time of year...).

Blackburn

X2 on the disconnect being your issue

cherokeebaby

I agree with Bowtie

blueyes1983

Thanks! I'll check that out next.

BlueXJ

Blueyes let us know what you find. All Cherokees did not have that disconnect axle. If you need to do something else we may be able to help. If you have that disco axle it can be converted to a mechanical actuation instead of the vacuum type. This would make it much more reliable. Let us know.

blueyes1983

Thanks for the help everyone!

I put the jeep back up on stands today and checked for the Vacuum Disconnect. I found it and started checking connections. As I followed the vacuum lines up into the engine compartment I found a line that had become unplugged (right by the tranny fluid dipstick). I plugged it in and Voila! My 4wd is working again.

Bring on the snow!

Jamie

drakan1908

Gotta love it when a repair is free

BuckB91XJ

There is a neat little trick you can do with zip ties right at your vacuum disconnect to keep them lines on there. There are known for coming off especially if you flex your front end out a lot while wheeling. Start saving now for a posi lock, though. I highly recommend relacing your vacuum disconnect junker with a posi lock of sorts as the stock set up just sucks. Good troubleshooting, there.

double_ot_xj

let me first welcome you to CF from Delaware. yes it is a state. good job on the free fix. its nice to see a female getting under the hood and checking out stuff for herself. maybe my wife can learn a thing or two from you. if you need anything else, don't hesitate to ask.

diskman

I pulled the cover off my disconnect on my '84 and used a stainless hoseclamp to keep the collar engaged on the stub shaft. Then I removed the fork (it was broken). Figure Jeep got rid of the disconnect in later years anyways so no biggie. Now I have 4x4 right away when I select it.