Hi,
I have two of these nice locomotives, unfortunately they do not run well. One I think is the victim of
wheel gears not in mesh(think that is the word) it runs, but terribly noisy.

The other one is what I search help for, it runs good forward, but is noisy and will stop frequently when going backwards on the same length of track.
Ideas, someone ?  could it be a gear problem ?  if so, is there somewhere a disassembly guide ?

Also, the mesh problem is, of course, worth fixing......
any ideas are very welcome !