I recently restored a DC motor from a Beogram 4002 (5513) turntable. The turntable exhibited the common issue of inconsistent RPM, indicating the need to lubricate the motor bearings. I documented this process in detail in a video posted earlier. Here are some observations from the motor restoration.

The first image shows the motor in its initial condition upon arrival:

This image shows the motor after disassembly:

The two small “donut” shapes in the front right of the photo are the bearings. These are Oilite bearings, made from porous brass pre-filled with oil. As the shaft spins, it gradually pulls oil from the bearings, and they eventually dry out. In this particular motor, the dryness was so bad that the shaft was grinding on the bearings, making a loud screeching noise. This image shows the bearings under vacuum:

The bubbles indicate air escaping from the empty pores within the bearing. The bubbling typically ceases after 12-24 hours:

At this point, the motor can be reassembled and tested. I used a 3D-printed tool to press the tabs of the upper bearing’s mounting ring back into position:

After reassembly, I installed the motor in one of my Beogram 4002s and used my BeoloverRPM device to measure the RPM over time. Other enthusiasts are welcome to utilize my BeoloverRPM device; simply reach out through the contact form on the right or send an email.

Here are the RPM curves before and after the restoration:

The blue curve represents the pre-repair measurements. I had to stop the test early due to loud noises and wide RPM fluctuations. The red curve showcases the motor’s performance after the restoration. It appears this motor is back in working order!