Beogram 4002 DC Motor Restoration

Two Beogram 4002 DC platter motors arrived from the UK. This post reports about restoring the first one. This shows the motor as received:

I disassembled the motor to get the bearings out:

The bearings are the two small donuts on the black pad upfront. These bearings are made from a porous material ("Oilite"), which has a limited amount of Oil infused when new. Over time this oil leaches out lubricating the shaft. When the oil is gone the shaft runs dry, which seems to be the case with most Beogram 400x motors these days.

I immersed the bearings in motor oil and pulled a vacuum:

Immediately, vigorous bubbling started. This is a sign of the air drawn out from the pores by the vacuum. Once the air leaves, the volume is filled with oil that diffuses into the material to replace the air ("nature abhors a vacuum"...;-). After about three days the bubbling came to an end and I assembled the motor for testing. 

I installed it in one of my Beogram 4002s and ran it for 24 hrs while monitoring the RPM every 10s with my BeoloverRPM device.

This is the curve I measured:

That is as good as it gets. This motor is ready for duty again!