I replaced both sides, inner and outer bearings, after driving though a flood. I bought the bearings from a Volvo Dealer, and each side came as a kit with bearings, seals, a tube of grease, and a great set of instructions. On another Volvo I bought bearing from an industrial bearing house and 1/3 the cost you get only the bearings and you still need the rest of the stuff. you must know how to remove a nd replace the bearing races and how to hand-pressure the grease into the bearing. Get a good manual, it's an eazy greazy job and the torque specs will be listed. Good Luck, Bob