To fully rebuild the platter drive system of a Beogram 4002 DC motor, you must relubricate the motor bearings. Many DC motor Beograms have fluctuating RPMs because the oil in their porous brass bearings (called “Oilite”) depletes over time. These bearings can be ‘refilled’ by using a vacuum to remove air and allow oil to replenish the pores. The challenge lies in extracting the bearings without causing damage. I documented this process in a recent video.

Here’s a look at the process, using the motor from a Beogram 4002 (5513) that I’m currently restoring:

This is the motor after removal:

And here it is completely disassembled:

When removing the bottom bearing, I’ve modified my technique. I now unsolder the feedback coils on the side I’ll be lifting to extract the bearing:

This change came after accidentally breaking too many of the delicate wires connected to the coils. They are very fragile and easily broken. Removing one of the coils allows the board to be lifted for easier bearing removal:

To infuse the bearings with oil, I used a FoodSaver vacuum pump and a mason jar filled with SAE30 motor oil. The image below shows air bubbles escaping the bearings as the vacuum is applied.

After approximately 12 hours, the process is complete, and the motor can be reassembled. I then tested the motor using my BeoloverRPM device:

This device logs RPM over a long period, which is useful for detecting intermittent problems. The graph below shows the RPM curves before and after the restoration over approximately 24 hours:

The lower curve represents the pre-restoration measurements, while the upper curve shows the post-restoration results. The negative spikes on the original curve indicate issues with the motor bearings. These spikes are absent after oil infusion. Enjoy your revitalized Beogram!