One thing I forgot to mention. Before you install the differential you might want to pull the cover and replace the solenoid and wiring harness that goes from to solenoid to the outside of the differential. That wiring harness has been known to go bad (according to QD II owners) and the solenoid is what locks the front diff when you flip the switch. The solenoid cost about $57, not sure the price of the internal harness as I didn't replace mine. I didnt know this was a potential issue until after I installed the differential. Also check to make sure the differential axle seals are good