Thanks Jonathan for the information on light mikado 2-8-2 shell removal.

For others interested, the light mountain 4-8-2 shell removal process was essentially the same:

1.  Gently pull the boiler stays out of the front sides of the boiler/smoke box (tweezers recommended for this).

2.  Remove the drawbar screw under the cab.

3.  Remove the screw underneath the lead truck, between the steam cylinders.

4.  Gently wiggle and pull the shell up and forward.

My long dormant light mountain 4-8-2 makes an irregular clicking noise (the noise is near constant but not in a regular pattern). The wipers on the drivers all look fine and touching where they should, the drivers don't appear to be out of quarter or misaligned, and valve gear mostly looks OK. (The one point at which valve gear parts might be touching slightly is not in sync with the clicking noises).  Also, I've very sparingly oiled the valve gear and driver bearings (Labelle #108), and run it (on the bench) at slow to moderate speeds in forward and reverse for about an hour (in the hope of working out any "set" in the drive belt). Running it only made the clicking worse.

UPDATE: I installed an NCE decoder. As a result, the clicking noise now is more like somewhat irregular growling. It still only occurs in reverse; forward is fairly quiet (though not as quiet as current production like the dcc/sound 2-8-2).

Thanks for any suggestions as to what else the problem might be. Also, does anyone have any experience to report about sending this kind of problem in to Bachmann for repair (at the cost of $45 plus shipping)? Or is this something one just lives with?

Can anyone provide any tips regarding shell removal for the light mountain 4-8-2 (version from around 2012, I think) and for the light mikado 2-8-2 (current version)? I've looked at the parts diagrams, but would appreciate any suggestions beyond what they provide. Also, if you have any tips on further disassembly for cleaning and lubrication, I'd appreciate it. Thanks very much.