Replacing a bearing in a motor is not a difficult task, provided you follow these set procedures. If a bearing is noisy or doesn't run smoothly it should be replaced. If a bearing is removed for any reason, it should be replaced with a new one. If it's necessary to replace one bearing, replace the other as well to prevent return service calls and pump down time.
Use only AOS bearings obtained from AOS and ordered by the proper AOS part number. Bearings obtained from AOS are built with balls having a specific fit, checked for sound level and filled with high grade grease for the temperature and service conditions. AOS bearings are lubricated and require no further attention during their life. Do not substitute. Do not reuse old bearings pulled from shafts because this could damage the motor and cause a return service call. After the power has been sut off and the motor disassembled from the pump follow these steps:
1. Mark the end frames and shell of the motor with two pieces of tape or a marker so the motor can be reassembled in the original configuration.
2. Remove the rotor and shaft from the shell by:
- For two Compartment design, remove the canopy. Remove the switch to get access to the governor on the end of the shaft. Remove governor springs. Remove governor weight by spreading the bracket with a screwdriver. Take out screw on end of the shaft and remove governor bracket.
3. Remove the four thru-bolts.
4. Remove th end frame opposite the shaft by putting a screwdriver in the notch and tapping the handle of the screwdriver.
5. Remove the shaft end frame using the same method. Carefully pull the rotor and shaft assembly out of the shell from shaft extension end. Be careful not to lose the washer and bearing load spring that is positioned in the bearing bore in the end frame opposite the shaft extension. Be sure to replace the washer and spring during re-assembly.
6. Remove the bearing locking screws from the shaft end frame.
- Note: New motors do not have a lock plate. They have a lock clip that is attached to the end frame with a single screw. The screw is located in one of the two holes that used to be used for the lock plate screw. Turn the screw 1/2 turn to release the bearing from the end frame.
7. Remove the shaft collars or snap rings used to secure the bearings. (you will need a pair of external ring pliers.
8. Use a bearing puller to remove defective bearings.
9. Install new bearings using a tube that presses only on the inner race of the bearing. Do not put pressure on the outer race of the bearing or the bearing will be damaged.
Re-assemble in revers order of the disassembly instructions. If the motor is a two compartment design make sure you adjust the start switch correctly (let me know if you need this part, it's a different section). Make sure there are no leads in the area of the rotating governor. When the canopy is installed make sure no leads are pinched between the canopy and end bracket.
Recheck wiring. Check rotor and shaft to make sure it turns freely by hand. Check motor for grounds before applying power.