Help,4x4 is making a clicking noise

I have a 1984 cherokee witha command track t-case and it makes this funny clicking noise only when it is locked in 4x4. i've changed all the u-joints and rebuilt the front drive shaft cv joint. also looked inthe front differential and all looks fine. Could it be the t-case?

Are you sure that the axle is completely engaged by the vacuum motor? When you reinstalled the axles, did you double check that fork and the coupler were properly aligned. If it only happens when you engage the 4x4, and you have new U-joints in the front axles, wait. Does it do this on turns only or does it matter. I would double check the double u-joint ( driveshaft to T-case). makesure that there is no binding at all, should move smoothly.
Try this, disconnect your front DS from the T-case. Disconnect the vac. motor. Engage the T-case. Does it make any noise? If not,than its got to be something in the front axle. Also make sure you have the proper torque on the FNT D/S to T-case bolts. Jeeps are funny about the little things.

I have a 2001 Jeep Cherokee Sport 4.0L and when I am in 4Low and shit gears I get a click sound

I have a 2001 Jeep Cherokee Sport 4.0L and when I am in 4Low and shit gears I get a click sound Just read your reply I got a little laugh because I would exspect more of a clunk and a splash.lol

Are you the original owner? If not the individual who had it before may have installed a locker or trak-lock of some sort. They are supposed to click when they are engaging/ disengaging...just a thought.