I posted this on the Bachmann forum
"Apologizes if this has been done before but I have Spectrum 1:20.3 Consolidation that has a split gear.
Applying power to the motor causes it to run but the wheels do not move and there is a ‘clunking" sound’ made by the gear.
I have looked at the parts store and the wheel assembly P/No 81209 has sold out.
Is there a replacement gear or wheel assembly that I can get to replace the failed one?
I am in Australia so a local supplier would be preferred if possible to save on postage.
I have previously used Barry’s Big Trains to repair an old big hauler but he has retired."
I had some replies but I am now spreading my net to the wider community for any others suggestions.