pictures

on the underside, there is a little screw but i think it just holds the motor in place 

and it doesn't look like the coupler pockets attach to the shell at all

Atlas Shell

There are little tabs on the base of the shell and cab. First, remove the handrails so you don't break them. Second, remove the cab by gentle pressing in on the sides and lifting the cab off.

There are five tabs on the hood, if I remember correctly, one at the front and two on each side one on each side towards the front of the engine and one on each side towards the cab. Gently press in on the side of the hood to release the tabs and rotate the hood upward from the cab end. You should be able to then gently slide the hood back ever so slightly to release the front tab on the hood.

These are great engines. Good luck and have fun.

Roy

Shell Removal Atlas S4

 The locomotive body in front of the cab lifts off by gently squeezing it by the walkway towards the front radiator grills.  A small tab holds it in place.  No screws need be removed to access the inside for decoder installation or access to the motor.  Once this is removed the other items like walkway and cab can be removed.  

  Greg

Thanks

Thanks, Greg, guess I was wrong and going about removing my shell the wrong way.

Roy

Cab First

Everything is held in place by tabs.  But I always remove the cab first.  Once the cab is removed, you can pull the hood straight up.

got it

thanks guys for your help!

Following your suggestions did work but actually it looks like on this particular model the tabs are actually:

1 on each side of the CAB and 1 on the very front

with quite a bit of pressure I managed to get the front one loose but it may have been easier to remove the cab first. I'll add pics in a bit for future reference of others who may come across this thread.

removing shells

This is one of my pet peeves. Many manufacturers don't tell you how to get the shell off. Atlas is one of the worst. They all seem to have a different way to do it and sometimes different on different locos by the same manufacturer. I have some unpainted units because I am reluctant to take off the shell.

Instructions!!!

Brian, I totally agree! The manufacturers typically include a detailed parts list. I don't know why they don't just add a blurb about shell removal - especially if it's a DC model and there's a very good chance that at some point the owner may want to add DCC.

Anyway, here are a couple more shots of the shell tabs for future reference. I found that my particular unit was very tight and it took a LOT of pressure to get mine off and i ended up breaking the clip. I think it might have worked better to remove the cab first. I also opened up another Atlas model this weekend (an FM H16-44) and it was also really really tight, even after the tabs were disengaged.