I've had some luck finding replacement parts like that by digging
through the servo spares box at the local RC model hobby shop.

Sam Goldwasser wrote:
You know those tiny inserts in timers and clocks that crumble after time.
They are the plastic pinion gear that fits into the magnetic rotor of
the common Intermatic timing motors.

Does anyone have a source for just these pieces? I have several
appliances that are either inoperative or from which I've been
"borrowing" these pieces to fix others.

A typical motor part number is WG-1420-1.

Thanks.

--- sam