If you're over 50k, I'd change the bearings. I did gears at 3x,xxx miles so I didn't worry about it. However, you will need new posi dif oil when you do the job along with some RTV sealant for the dif cover.
2007 4.0 Redfire Manual
93 Octane Race Tune by BAMA with 3k launch limiter, JLT CAI, Custom H Pipe to Dual Flo Pros, T-Lok w/ 3.73s, Hurst Short Throw, Springtech Lowering Springs, GT Front and Rear Swaybars, MM Aluminum Panhard |GT Front Bumper, Fiberglass Black Hood, Shaved Antenna, Smoked Everything, 6Ks, Sequentials, etc. | 2011 Takeoff Black Leather w/ White Stitching