Front wheels not spinning when in 4 wheel drive

I just got a '92 Cherokee from my parents and the four wheel drive is not working. When I put the lever into 4H or 4L the front wheels don't spin. The Part-Time light on the dash does not come on either. The four wheel drive worked fine last year but now it is not.

I put the vehicle on jack stands and ran it in first gear, 4H. The rear wheels spin but the front do not. I peeked underneath and the front drive shaft does spin. it seems as though the front hubs are not engaging.

Help?

TIA.

Sounds like a vacume line problem. I cant remember if yours had a axle disconnect either. Check all the small plastic lines under and top side for wear or just being broken.

yeah thats what i figured, I checked all the lines I could find coming form the transfer case to the axle and all the ones under the hood and didn't find any problems... maybe i need to do a more thourough (sp?) check in a couple days...

The XJ doesn't have manual or automatic hubs, so that's not your problem. And the 92 should not have a disconnect axle -- I believe Chrysler had stopped using it by then. You can check that by looking at the right (passenger) side front axle tube. If the tube runs straight from the differential housing to the outer end where the ball joints are attached, and the upper control arm attaches to a sheet metal "tower" that's welded to the top of the axle tube ... you don't have a disconnect. The disconnect is a large-ish cast iron housing that would be on the passenger side axle, between the differential housing and the outer end. If present, it'll have a vacuum-operated shift motor hanging off the bottom with a multi-tube vacuum harness leading to it.

I think your problem is inside the transfer case, but it might be as simple as adjusting the linkage.

my fsm shows command trac is disconnect select trac is non-disconnect.... have you changed your diff fluid lately... 80w90 or you can have engagement issues... linkage might possibly need adjustment, which is done in 4 lo, with the trunnion nut. otherwise sounds like an internal issue.... good luck.

well I just got around to looking inot the problem more in depth did some vacume tests and as it turns out the vacume shift motor on the axle leaks. does anyone know how much one of these things is gonna set me back?

I tried Autozone and NAPA but no luck, I guess it's a dealer only part...