Hanging Monorail Motor Stripdown & Fix

I have a Shonan 5000 hanging monorail unit that's never been right since I got it, it's always been erratic and jerky, with a marked tendency to snag and stop at every rail joint unless alignment is absolutely perfect. Today I finally got around to stripping it down so that I could investigate.

First I'll show the gearbox stripdown sequence for reference:



Everything cleaned up, motor oiled, gears and spindles greased, re-assembled and although it was all running smoother and quieter, the basic problem still existed.  I did notice two things though, as indicated here:



A: two of the spring-loaded wheels that push the rubber drive-wheel against the track have lumps on them, artifacts remaining from the moulding process. I trimmed and filed these smooth.

B: one of the wheels is slightly out of alignment with its opposite number.

Stripping the motor unit down again, I found that slacking off the screw that secures the spring-loaded wheels, C, by about 1/3 of a turn, bought the offending wheel back into alignment.

Result, the unit now runs fine, negotiating track joints without complaint. Two hours on a rainy afternoon well spent!