Beogram 4002: Restoration of DC Platter Motor

I recently received a Beogram 4002 DC platter motor from the Netherlands. Unfortunately, I was not able to restore it since someone had previously destroyed the top bearing suspension, which I was not able to bend back into a sufficiently precise shape.

Therefore, I restored a motor that I had available:

I disassembled the motor to extract the bearings for oil infusion:

I immersed the bearings in motor oil and pulled a vacuum. Immediately, vigorous bubbling started:

This indicates that air is being drawn from the pores of the bearing material, making room for oil to diffuse into the bearing. After about 48 hours the bubbling stopped and I extracted the bearings:

I reassembled the motor and installed it in one of my Beogram 4002s for an RPM stability test with the BeoloverRPM device:

After about 24 hours I had measured this curve:

This is pretty much as good as it gets with the Beogram 4002 DC motors, i.e. this motor is ready for duty again!