I have an Atlas GP-40 (Model no 9708) that has one of their dual decoders installed (Item #342). I have to remove the shell in order to get to the decoder so I can relocate the jumper plug. I have removed the coupler boxes as an interference to removing the shell; but the shell seems to be on pretty tight; does anyone have any experience in removing the shell from this Atlas model locomotive? It does not seem to wiggle, and I am leery of just using a bigger scrrewdriver, without knowing if there si a"trick" to getting the shell off.
The Atlas GP’s have three pairs of tabs, near the front of the body, just behind the cab, and maybe an inch or so from the end of the long hood.
I usually start with the end of the long hood, squeezing the shell with my thumb and index finger right above the walkway, while at the same time wiggling from side to side and pulling upwards. They are a tight fit, so it does take some force to release the tabs and get the shell off. Complete instructions are here.
However, if you just want to move the jumper, all you really need to do is remove the dynamic (or non-dynamic) hatch from the long hood. Instructions for that are here.
So no spitballs in my original reply, which covered the two options for accessing the decoder to move the jumper plug in, um, Atlas HO scale GP40’s that came equipped with Atlas 342 dual-mode decoders. [;)]
Thanks for the info, the shell was a tight fit, but I was able to remove it and flop the jumper. It took me a couple of tries to get the shell back on/stay on, . However, after all is said and done, it was much better design than a couple of my mdc roundhose RS-3 models of old, that the shell comes off if you pick up the loco by the body, those tabs just do not work very well.