Atlas SD-40, shell removal

Terry: I'm going on memory here as I last had my Atlas SD40's apart last year for routine lube after coming out of extended storage. I'm looking at my UP version; I believe you'll find the shell comes off in three separate pieces - the rear long hood comes off first by removing two black screws you can access through the gap between the side frames and the truck block. These two screws are located between the outer-most wheel-set and the center wheel set. Try to move the rear-most part of the shell upward while at the same time gently squeezing the shell where it enters the back of the cab section-most Atlas diesels have lock tabs here to release the aft hood from the cab molding.

Once the aft hood is off, you'll need to carefully release the handrails that are hooked into the cab from the front and aft sections. Once the handrails are released, I believe you should be able to gently remove the cab. By now you will be in the area of the switch in question and likely re-tighten without removing the front hood assembly which is held by two more screws inserted from below the frame just forward of the center wheel-set.

Hopefully this works for you; good luck!