Cleaning and oiling the sub-platter bearing
Thorens belt-driven turntables have an inner platter, or sub-platter, linked to the motor spindle through a rubber belt. The belt transmits rotation from the motor to the sub-platter. The outer, heavy metal platter rests on the sub-platter. The sub-platter has a bearing shaft inserted in its housing, an oiled cylinder well in the floating sub-chassis.
Decades of use may have not affected the metal bearing shaft of the sub-platter. But when buying a used turntable, its conditions are among the first things to check.
The sub-platter should rotate with no noticeable wobble nor excessive noise (or no noise at all). It is better not to insist in rotating the sub-platter, since the oil in the well could be old or even missing…
A quick glance at the shaft will tell if it is damaged or not. Circle scratches around it could be the sign of wear due to prolonged un-oiled rotations. The shaft must fit snugly in the cylinder housing, with no play between the shaft and the well’s wall.
Inspection of a Thorens TD-165’s 10 mm bearing shaft housing in the sub-platter. The thrust plate, a circular metal piece at the bottom of the well should show no wear: it is where the bearing shaft tip rests while rotating. In case of need a new thrust plate can be installed over the old worn one.
Clean the well from the old oil or deposits with a cotton swab; clean the shaft with a soft cloth and oil both shaft and well. Sewing machine, gun lubricating, as well as car motor oil, are all suited for the task.