Just went out to pull a friend out of a little mud hole. I had good footing so I tried first in 2WD. Couldn't get him out so I moved it to 4LO and pulled him out.
When I was pulling in 4LO I heard a very loud chatter that sounded like it was coming from the left front. When I moved it back to 2WD the chatter goes away..... mostly. When driving down the road you can hear a faint chatter like noise if you listen for it.
Axel U-joint has no noticeable play or movement.
2009 JKU on a 4" Rancho Sport lift with 35" KM2 on stock 3.73 gears Dana 30 front
'09 JK Unlimited X. Yellar. Hard Top, S-Package Factory rear locker and front sway bar disconnect. 3.73's which will have to go someday. 4" rancho lift with 35" BFG KM2's, AEV Snorkle, FlashPak