Atlas 3R RS-1 6883-2 Vibration from Railsounds

Jim: I have the NYC RS-1 version which I converted to ERR after the EOB self-destructed a few years back. I have not had an issue with the shell vibrating due to the RS operation; maybe your shell is not seated correctly on the frame??? Or is the speaker loose in the fuel tank???

This engine comes apart by pulling the handrails from the cab assembly, then loosen the screws at each end of the loco that secure the long and short hoods. Remove the steps from each side of the cab (friction pin fit in the frame). Next slide the short hood upwards until you can disconnect the wiring; next remove the cab. Now that the cab and short hood are off, you can swing the long hood upwards starting at the cab end ( maneuver the long hood up and away from the smoke unit.

I've heard of this, though I haven't experienced it myself.  Try a little foam to keep the end of the shell from vibrating.

Experiment with a temporary small shim or two (either/both sides) between the chassis and the bottom of the shell. Toothpicks/whittled wood and the like. If one or both stop the noise, it probably means that the problem is the shell/chassis interface rather than parts inside touching the shell. This could save you a disassembly session, never pleasant on most modern, high-end 3RO diesels. A permanent, low-visibility shimming arrangement is a possibility.

If the sound persists or mostly persists, you will probably want to open it up - but first try turning the loco over and over in your hands a few times; shake it - gently - to see if you can move the offender out of the way without surgery. I've done all this, and sometimes it worked.

Remember that it could be more than one thing.

Try GRJ's method before taking it apart. If you think D&H's explanation is involved wait till you try it for yourself. Having an adult beverage handy wouldn't be a bad idea.

Oete

I was contemplating removing the fuel tank and trying to squeeze card stock shims under the shell. Can’t be done from outside as the shell sits into a recess in the chassis. 

Thanks.