Jeff,  Thanks for your helpful reply.  We will follow your advice and look for FT's instead of trying to fix the F9.  We'll just have to wait until next spring, when the train shows will (hopefully) reopen in our area.

Does anyone know a good source for the rear truck and motor assembly (#2106) for a HO EMD F9 Diesel?  I don't see it listed in the Bachmann on-line parts store.