Well, I gotta tell ya. I'm starting to understand why Weaver went out of business.
I've replaced the bits as above and the loco runs very well at slow speed, but above notches 1 and 2, the drive train rattles very loudly.
The sound of the frequency of the rattle is the same as the tail shaft rotation - but the rattle is coming from the rear drive truck. I 'end for ended' the square brass shaft, and checked it with a straight edge, but that hasn't helped.
The rattle is coming from the rear truck (the one with the chain). It's nearly loud enough to drown out the sound decoder.
Experience tells me that I might need to disassemble the gear boxes between the wheels as there is a lot of play there. Adding shims might help to tighten it all.
A very disappointing product.
