you should get an overhaul kit. It is all the bearings and lube and all that good stuff. highly recommended especially for that 10 year old rear end. hell, minds well buy an extra ABS sensor bc its very likely one of those bastards will crack and break. This would be a good time to have your mechanic make sure your axles are still in good shape. When I opened up the differential, my bearings were cutting away at the axles and if i had gone another 5k miles, i wouldve really messed something up. Putting in gears isnt hard, just gotta be careful. Not for the beginner mechanic.