Hey sorry for all the posts, Finally got the vibrations and wiring fixed in my newly purchased XJ, We got about 12 inches of snow in the past 2 days and today I find out my 4wd doesnt work, not surprised on this thing haha, If I pull it down into 4 Hi It drives normal, and 4 Lo def has low range but still only rwd, New to Jeep world, Only 4wds I've ever owned were Yotas with manual hubs so Im lost right now and trying to learn more

Oh yeah the rig is a 87 XJ 4.0 5 speed

 

your vacuum actuator failed somehow. search on here and google for remedies from cheap to expensive.

 

front axle is vacuum disconnect and either the lines are broken or something in the axle is.

 

Most likely vac disconnect, those things suck. Doing a full axle swap on my 91 to a 95 front soon. That way I get rid of the vac disco and get to upgrade to the larger u-joints.

 

Thats what I was reading on here, Im gonna search for some fixes, and hope for no more snow for a few days haha

 

All i did was to take the actuator piece off altogether and put washers in the housing to keep the sleeve 'locked'. Later on jeep made the axles one piece, so it wont hurt anything. Ive done it and now my 4wd works flawlessly.

Again, there are several fixes, from the cost of 12 washers and some gasket maker all the way up to the posi lok kit for a couple hundred bucks. I went with option 1, and it was a grand total of 6.00

 

when i had that there was a crack in the vacuum line so i replaced it with i think vacuum hose and ran it the length that was broken. Just got some hose that the ID was = to the original hose's OD and worked great. I thin it cost me like 10 bucks. The cracks on my line was right under the battery. I think the battery leaked on it and corroded the lines.

Only issues i had was the lines were reversed so it didn't work then i swaped the lines to the correct way an worked fine.

So just crowel under the jeep and follow the line from the front to the rear and see if there is any breaks or leaks. Next i woudl move on to seeing if the fork is stuck

 

Yeah I will crawl under there as soon as I get some dry ground to lay on