Owner put too heavy an item in the oven and the rotary drive made horrible loud regular clatter noise after that, but cooker works still. On receiving it was still making loud click noise of about 2 per second, very loud disturbing noise. By the time I'd taken it all apart and testing the synchronous motor and 4 rev / min gear train, on mains , all apparently working order.
Took motor apart As 2/sec, presumably second to last gear clicking against previously stuck last 30 tooth gear. The small locating pip on the end of the final gear pin looks as though it had bent and now returned of its own accord, reinforced plastic. No wear on any of the gear teeth on any of the gears. How to avoid it happening again. PTFE washer under the part that protrudes into the oven ?
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on