So I recently installed a rubicon express 4.5" lift with 31's. Installed a tcase drop kit. Since the lift I get a grinding noise on deceleration. Not when braking just when I take my foot off the throttle at 30+ mph. It gets louder as speed increases. Already replaced front wheel bearings. Checked the dust plates weren't rubbing on the rotors. Pulled the front drive shaft and no help no wiggle in the front pinion either. Rear drive shaft has no play in it. I'm thinking either something in the front axle or tcase/transmission? Has anyone else experienced this? I want to see if anyone has any input before I go crazy replacing bearings and seals everywhere.

 

Could be the front axle u-joints, especially if you pulled the front driveshaft

 

When the transfer case drop was added did you re-adjust the transfer case linkage? What trans do you have auto or manual? How do the trans mount and motor mounts look? Take off the rear driveshaft and drive in 4Hi and see if it still grinds.

 

I didn't adjust the linkage, didn't know I needed to. Auto trans. Motor and trans mounts are both sagging. Brown dog motor mounts and an OE trans mount are awaiting delivery. Pulling the rear shaft is my next step in troubleshooting. I may do that this weekend and see if the noise is still there.

 

when I did the front wheel bearings I pulled the axle shafts sand the ujoints seemed okay, they don't wobble at all when they're in. I'll keep that in mind though.