STEP 1 -- Tools Needed
Cleaning the motor is a fairly straight forward process. You will need a 3/32" hex wrench and a small pair of needle-nose pliers.
STEP 2 -- Disassemble The Motor
The first step is to remove the front end bell from the motor. The motor is held together with three long 4-40 cap screws. Loosen the screws with the 3/32" hex wrench and remove from motor.
STEP 3 -- Remove The Front End Bell
Remove the front end bell from the motor--If seems stuck, pull it at an angle to break it free.
*You should note that there is a piece of insulating paper inside the end bell--Be sure not to lose it or any of the shims that may be on the rotor's pinion shaft or stuck on the bearing.
STEP 4 -- Remove The Rotor
Grasp the pinion shaft of the rotor and slowly pull the rotor straight out of the motor. If it seems to be caught or the magnetic strength is holding it too hard, use the needle-nose pliers to hold the pinion shaft and pull the rotor out.
Carefully set the rotor aside on a clean towel or soft surface--The high magnetic strength of the rotor will attract it to other metal objects, and contact with a hard object can easily crack the magnet.
STEP 5 -- Clean Out The Motor
Using a soft bristle brush or compressed air, carefully clean the inside of the motor being sure to remove any dirt and debris that may have found its way inside.
Never use solvents such as motor or brake cleaners to clean out motor.
STEP 6 -- Clean The Rotor
Use the brush or compressed air to clean off the rotor, paying special attention to the bearing and magnet surfaces. The rotor is highly magnetic so metal debris may be stuck to it and must be removed to prevent damage to the inside of the motor.
STEP 7 -- Clean Out The Front End Bell
Use the brush or compressed air to clean out the front end bell housing, paying close attention to the bearing. This is a good opportunity to check the bearing to make sure it operates smoothly--The bearing's inner shield can be oiled if desired, but do not use more than a drop or two of oil or it will attract dirt and debris.
STEP 8 -- Inspect The Motor
Visually inspect the interior of the motor to be sure that it is free of debris that may interfere with the rotation of the rotor.
STEP 9 -- Install The Rotor
Re-install the rotor into the motor by grasping the pinion shaft with the needle-nose pliers, and slowly and carefully sliding the rotor down into the motor until the shaft is properly inserted into the rear bearing. A small plastic tube (like the one shown here that we ship our rotors in) or a rolled up piece of a business card can help protect and center the rotor as it is inserted into the motor.
STEP 10 -- Install The Front End Bell
Re-install the front end bell and the 3 main 4-40 cap screws onto the motor, making sure to put the paper insulator and any removed shims back in place.
STEP 11 -- Tighten The Screws
Use the 3/32" hex wrench to slowly tighten the three main 4-40 motor screws, making sure there is no binding of the rotor as it is tightened--The rotor should be able to spin freely at all times.
STEP 12 -- Check The End Play
Check that the rotor has the proper amount of free end play. There should be approximately 0.010-0.020” (0.25-0.50mm) of end play. If necessary, add or remove shims from the pinion side of the motor shaft until the proper amount of end play is reached.