I tried removing the screws that hold the cover to the back of the motor, but the cover still wouldn't come off. I pried with a knife but couldnt even get the edge in -- i think it is glued with epoxy or another strong glue.

Then I removed the screws that hold the motor to the gear assembly, and it came off easily but only the motor's drive gear was accessible. It's a module they did not intend to be user serviced.

The age is circa 2001, and it's a chain drive unit to mate with the Whitlock pedestal.