have a 90 cherokee with 5" rubicon express lift D30 C8 1/4. i swapped out the D30 CAD vacuum axle with a D30 non vacuumm axle out of a 96 or 97 the jeep only had 117k. after swapping the axle (bc the old one broke big surprise right? Not!) when i stop or when im coasting it sounds like a slight grinding sound. also when its in 4HI or 4LO it makes even worse sounds and jumps when turning at any angle, like something is binding? i have good pinion angle with both front and rear drive lines and both DL's have new u joints and i have no DL vibes. could it be the ujoints in the axle its self? or could it be the bearings on the outside Nuckle? any ideas im not a master service tech but i can work on my own junk. lol

 

Is it the same gearing as the rear axle?

 

yes same gear ratio 3.55. any ideas please need to get this Heep Fixed

 

it sounds like either the centering ball in the front drive shaft (double cardan/cv joint) or front axle u-joints.
however, my guess would be axle u-joints since you just swapped that axle in. especially if that axle has been sitting around for a while before you put it to use.