Been searching and trying to figure this one out for a while..

My girls 01 XJ has a 4"something lift and was getting vibration out of the front DS so it was removed it for the summer under the "better gas mileage" excuse before we got the jeep. When going in reverse or forward at >10mph im hearing a constant gear contact noise from the front D30 diff (low tone metal on metal clicking). The sound is more pronounced in reverse and frequency correlates with speed. I did a full fluid drain/clean/refill. Fluid was full, black, and absent of and unusual signs of wear though it looked like original gear oil on the 130k diff. No pitting, missing teeth or noticeable problems of the ring and spider gears or what i could see of the pinion gear.

Anyone with ideas? Bout ready to put the front DS back in to compare and troubleshoot the vibration (bad cv joint likely) Im guessing something to do with pinion bearing/backlash in the absence of the front DS? Im not very experienced in that this was my first exploration into a diff at all, learning and breakneck speed however...

 

Assuming the u-joints/CV and unit bearings are good. I'd be checking the spiders.

 

eliminating the DS as a problem for now as its removed im focusing on the diff.. spider gear bearing? What else should i look for besides chipped/pitted teeth within the box. There was a minor amount (3/16) of play in the gears to one another but i assumed that normal, no rocking or wiggles to indicate a bad bearing tho.