Thorens TD124 E50 Motor Rebuild Service
The lubricant which was originally chosen by Thorens’ tribology team for the TD124 main bearing, motor bushings, and step-pulley bushings, is all but guaranteed to be hardened and ‘gummed-up’ after all of these years. In the TD124, these are sintered bronze bushings which have a micro-porous, lubricant holding structure which is meant to maintain a film of oil in these bearings over a long period of time with minimal maintenance. Over time, bushing and spindle wear happens, contaminants are pushed into the sintered structure, the oil hardens and dries, and the lubrication fails. After the lubrication fails, wear happens rapidly. In some cases, the hardened and gummed up oil will seize the motor. If the deck has seen much run time without adequate lubrication, the bushings and spindle will wear. In extreme cases, the spindle can be damaged.
After all these years, your E50 TD124 motor needs to be professionally rebuilt. Over the years, many of these decks have had all kinds of lubricants dripped into the bearings by well meaning owners, with some choices being better than others. However, adding new oil does not mitigate the fact that the old hardened oil is clogging the micro-porous oil holding structure of the bushings, and that the years of contamination are locked in by this hardened oil. Adding fresh oil to the bearing will act as a temporary fix, but really, your E50 needs new pressed sintered bronze motor bushings. In the odd case that your motor’s bushings are not excessively worn, your old bushings are almost certainly clogged, and there is no way to effectively clean them. It is also almost guaranteed that the old ‘oiling’ felt rings which are meant as a ‘reservoir’ for lubricant, are also gummed up hard and dry, no longer providing lubrication. When it is time to service your 124, it really is worth installing brand new pressed sintered motor bushings. Your ears will thank you.
An E50 motor rebuild should always include installing new pressed sintered bronze bushings and new oiling felt rings. We only use high precision, pressed sintered bronze bushings in the E50 motor. Machined phosphor bronze bushings are available for the TD124 motor, but we strongly advise against their use. Likewise, we do not like machined sintered bronze bushings for the TD124 motor, but these are also available. We use pressed sintered bronze bushings from AudioSilente.
TD124 Motor Upper Case Half showing new pressed sintered bronze bushing and new oiling felts. New bushings are impregnated with specialized lubricant in a vacuum chamber prior to installation.
Some insight into your TD124 E50 motor’s health can be had with a few simple observations. Does it start? Is it noisy? Can you feel ANY play between the motor shaft and the bushings? How long is the motor spin down time with the belt removed? And lastly, does it spin very close to 1740rpm when warm? (120v @ 60hz) Motor spin down times when warm should be over 20 seconds, though spin down time by itself is not a reliable indicator, as in the case of worn bushings, very long spin down times can be observed.
Our rebuild process for the E50 motor begins with checking on it’s current condition.
After your motor is disassembled, the case halves are cleaned, and the coils are checked for continuity and resistance within the correct range.
Measuring TD124 Motor Bushing Bores and Spindle Diameter
Deltronic ‘Tenth’ pin set for measuring TD124 motor bushings to within 0.0001″ accuracy
TD124 Motor Case interior. Case halves have been re-plated in a precious metals lab with the original plating metal.
TD124 Motor Case Exterior. Bushing retaining caps are fixed with new rivets.
TD124 Motor spindle thrust ball is replaced with a Grade 3 Silicon Nitride ball bearing.
New TD124 Motor Thrust Pad
We stock Audio Silente Motor coils in case your motor’s coils are damaged or defective.