Given the great interest in turntables now, especially quality decks like the Kenwood KD-600/650, I thought I would share some images I took whilst servicing the motor and bearing of my own KD-600.
The Kenwood KD-600 / 650 is a classic direct drive turntable from the late ’70s. The KD-600 is a superb deck technically, for a number of technical reasons: 20 pole, 30 slot brushless motor, synthetic concrete-composite chassis, 3 kg platter, massive main bearing assembly and so on.
One way to tell you need to service the bearing is if you’ve noticed a gradual increase in rumble, or if you can feel any wobble in the platter if you GENTLY press on either side of it. The bearing tolerances in this deck are such that you should feel no wobble with a properly maintained bearing.
The KD-600 bearing assembly is serviceable from above or below. The bottom of the bearing assembly features a metal bearing cap and rubber sealing gasket, held on by three small screws. This can be removed and oil added to the bearing with the deck inverted, but I prefer to remove the platter, motor top-plate and rotor, with integral spindle bearing shaft. This exposes the whole of the inner bearing well, meaning it can be thoroughly cleaned, and then a few drops of quality synthetic bearing oil added to the clean dry well.
You want to be sure to use lintless cleaning materials so as to not leave any fibers in the bearing well that could become caught between the well and shaft. It’s also extremely important not to overfill the bearing – I use an oiler stick which allows me to deposit the correct number of drops of oil in the bearing. NEVER just pour oil straight in as you will overfill it and oil wil spill out into other parts of the motor.
Once you have the correct amount of oil in the clean bearing, you have the fun part to do and that is reinstalling the rotor into the motor. As I mentioned, these are tight-tolerances motors, and on my deck it takes several hours for the rotor to displace air inside the bearing and drop into place. Never force this part of the process, just allow it to settle back down naturally into place. You can spin the spindle in your fingers by all means, just don’t press down on the rotor – we don’t want to create a high pressure situation inside the bearing.