Hy zinkschevy, you won't know for sure what needs to be replaced until you dis-assemble, clean and inspect everything. Check before dis-assembling to see if there is any clearance in the bearings, there should be none, the bearings should have a slight preload to them, both on the pinion and the ring gear. Any play could indicate worn bearings to the point that they require replacement. If when you have everything dis-assembled and cleaned you posted pictures, we could look at the bearings and give our opinions on their serviceability. Most overhaul books have pictures of bearing wear that you can compare with, hope that helps.
