Often a flat spot on the idler wheel. The manual shows how to adjust the linkage to ensure the wheel retracts when the player is off.
The TD-124 uses an idler wheel to transfer motion from the motor to the platter rim.
The idler wheel rubber often hardens or develops flat spots.
The Ultimate Thorens TD124 Service Manual & Restoration Guide thorens td124 service manual
Push the spindle down into the housing slowly. The tolerances are so tight that it may take several minutes for the spindle to sink to the bottom under its own weight as air escapes. Do not force it down. Section 4: Pitch Control & Mechanical Adjustments
The main bearing shaft must spin with absolute freedom. Any vertical or horizontal play introduces low-frequency rumble into your audio chain.
Use a microfiber cloth dampened with isopropyl alcohol to clean the chassis, stepped pulley, and inner rim of the main platter. Remove every trace of black rubber dust and old oil. Step 2: Motor Disassembly and Rebuilding Often a flat spot on the idler wheel
The rubber edge must be pliable, perfectly round, and free of flat spots. Flat spots cause a distinct "thump-thump" rumble sound during playback.
Essential for identifying original parts and sourcing replacements.
What (e.g., speed drift, noise, or startup delay) is your turntable experiencing? The idler wheel rubber often hardens or develops flat spots
Clean the spindle shaft and the inside of the brass/bronze sleeves with solvent until completely dry.
Remove the two or three screws at the bottom of the bearing well to remove the thrust plate. Clean out all old oil from the well using lint-free cotton swabs.
Safety & Best Practices
The idler wheel is the primary source of mechanical rumble if it is not perfectly round or if the rubber has hardened.