There is nothing to rebuild in a Birfield, you take them apart to inspect them for cracks and clean them up. Stock ones come apart easy and is covered in the FSM, Longs are another story, but they do not come apart as easy, but they do come apart.. I have always a high tack molly red grease with success. CV grease is not called for in the FSM, it says to use Molybdenum Disulphide Lithium Base grease, what ever that is.