It could be just bad bearings, but I often see where the bearing has spin in the end housing of the motor and wore it over size. So if you get to the point of tearing it apart, be sure to check the fit of the bearings in the motor end housings. If the housing is ruined you can buy replacements at a good motor shop. They will have to order them. As far as replacing the bearings you will need a puller to get them of. To install the new bearings best thing is to press them onto the shaft, but if you are careful you can drive them onto the shaft with a hammer and punch, or a piece of pipe. Be sure to drive on the inner race only!! If you put any force on the outer race you will ruin the bearing! Greg