The two circuit boards that needed component updates are finished. Now, I’m focusing on the Beogram 4002’s cabinet and its mechanical parts.

I prefer working on the floating chassis with it removed, which is easier since I’ll disassemble most of the tangential arm.

This revealed some hidden issues.

Initially, I believed the three chassis lock bushings were okay because they looked fine. However, examining the locking mechanism showed otherwise.

This was the first indication of the bushings’ poor condition.

The more I touched the old bushings, the more they deteriorated.

Thankfully, Beolover offers replacement bushings, so I ordered a set.

Next, I examined the tangential arm drive assembly, opening the ball socket containing the nylon nut that drives the assembly.

The old grease had hardened. The service manual specifies an oily consistency, so I’ll clean and re-lubricate it.

Here are the cleaned tangential drive parts.

During reassembly, I’ll replace the plastic pulley with an aluminum one from Beolover.

This photo shows the replaced arm position sensor lamp with a new LED.

Here’s the original LED, which is usually dead by now. Testing confirmed it was indeed not working.

I replaced it with an amber LED.

I’ll adjust the lamp’s position to align its light with the arm position sensor, according to the voltage specification in the service manual.

I removed the tangential tracking sensor’s lamp to replace it with Beolover’s LED module.

With the module removed, I can see the metal tracking sensor shutter (on the tonearm base) seems correctly positioned.

It shouldn’t touch the sensor’s black plastic housing but be close. The manual recommends a 1mm gap.

The remaining tangential arm assembly components are clean and move freely. While some parts will require adjustments according to the service manual, the arm lift mechanism operates smoothly.

Besides lubrication on some pivot points, the arm assembly needs no further disassembly.

I applied a lubricant mixture of Rocol 1000 and Mobile NUTO H32, as recommended by the service manual, to the tangential arm drive spindle. There are alternatives if these specific products are unavailable. However, I prefer using the original B&O materials.

I applied a thin layer of white DX Molykote paste to the two tie-rods that support the tangential arm assembly.

The floating chassis is reassembled. Now, I need to install the new bushings from Beolover for the chassis locks and place everything back into the Beogram’s cabinet.