Following the repair of the Beogram 4002 (5523) arm lowering mechanism, I removed the circuit boards for refurbishment. This presented an ideal opportunity to swap the deteriorated transport lock bushings with 3D-printed replacements. The old bushings tend to break down, scattering fragments within the Beogram’s casing, often lodging beneath the floating chassis. These fragments can obstruct the chassis’s movement, hindering its ability to isolate the turntable and tonearm from the enclosure.

To thoroughly clear these fragments, the floating chassis must be completely removed, necessitating the prior removal of the circuit boards. The chassis, still in position, is shown below:

And here is the enclosure after the chassis has been extracted:

Removing the chassis involves disassembling the transport locks (small components found near the enclosure). It’s crucial to label the upper and lower nuts during this process, as they are reverse-threaded, and to ensure the longer section of the lock bolts faces downwards. A close inspection reveals three bushing fragments concealed beneath the carriage:

With the enclosure space vacuumed, I proceeded to install the new lock bushings. A full set of bushings, each composed of two parts, is pictured here:

These bushings are available through the Beolover Shapeways store. Replacing all three bushings requires an order of six parts.

One of the sub-chassis orifices designed to house a bushing is shown below:

One section of the bushing is inserted from below:

The other part is then added from above, completing the assembly:

After fitting the remaining two bushings, I reinstalled the sub-chassis. Here, one of the locks is partially assembled:

And here it is fully assembled:

Now, it’s time to move on to the PCB restoration!