Beogram 4002: DC Platter Motor Restoration

I recently received the DC platter motor of a Beogram 4002 from a customer in Ohio. The deck showed the usual RPM variations indicative of dry motor bearings.

This shows the motor as received:

I disassembled the motor to extract the bearings:

The bearings are the two small donuts on the black pad. I immersed them in synthetic oil and pulled a vacuum. Immediately bubbling started around the bearings:

The bubbles represent air being drawn from the porous Oilite material. As the air leaves the bearings fresh oil can diffuse into the evacuated pores. The process took about 2 days until the bubbling stopped.

I reassembled the motor and then it was time for a 24 hrs RPM stability measurement with the BeoloverRPM device. It is able to log the RPM every 10 seconds into a serial port of a computer. This shows the BeoloverRPM in action:

This is the data I collected over 24 hrs:

There is still a degree of slow long-term RPM variations. These should go away after playing a number of records, which will polish the bearing surface in its new position. This motor is ready for duty again!