Help with Kiekhaefer trim tab motor
 

Hi guys,
Had a issue with the starboard trim tab pump this spring not working. Both solenoid clicked, but no motor. When I got it all apart the shaft on the motor had some resistance. I took a pliers to free up the shaft, and tested with the battery. She works great, so I put it all together, an I have a operational assembly.
My question to you guys is. Has anyone opened up the motor housing for maintenance? It's a square style Kiekhaefer motor with 4 screws on the shaft side of the housing off a metal pump reservoir. I was thinking I could lube the bearing check the brushes. I didn't want open it up, and have something shoot off. Any tips would be appreciated.

Thanks.