Okay I was having trouble with my 4wd not engaging, I took the vacuum thing off the front D-30 to find that the axles were not lined up, so that little thing that slides over and locks both axles together wasn't working. Well I fired up the Cherokee and put it in 4wd, jacked up the pass. front and moved it back in synch, slid the little thing over, then put the vacuum crap back on. Part-time light was working, and I drove it around a bit to see if it was okay, and it was. So I park, put it back in 2wd, then shift back to 4wd and got the same damn problem, it won't engage. What is the problem here?? 
