1. Use the Serpent cleaning clay:
Serpent Cleaning Gum (Part no. 1690)
to pick up and remove exterior dirt.
2. Remove rubber seals with an Xacto from the inner race and pry.
3. Use RPM bearing blaster:
in combination with a cleaning solution...
such as electric motor cleaner spray.
4. Dry them.
5. Clean the seals. (just spray them clean with the motor cleaner and make sure no dirt is left behind.)
6. Apply LIGHT bearing oil to balls. Oils I highly recommend are:
Serpent Premium Lube (Part no. 1683)
Serpent Bearing Lube (Part no. 1682).
7. Rotate the bearing so that lube will contact all the balls and lines the races,
8. Then reapply the seals.
Regular maintenance provides for prolonged bearing life and an extremely free drivetrain which is always a good thing.
Hope this helps you. Good luck!
All of these fine products can be found at your LHS, and if not, you can contact Kamikaze Toys and Hobbies: www.kamikazetoysandhobbies.com