I have 4 SD40's, all HO DCC equipped without sound, and I would like to add sound to them. Doesn't look to be very much room for the speaker in the top of the cavity. Anyone done this before and if so, what did you install?
Been there , lots of metal in these but if you have a drill or a rotary tool it will make short work of the soft metal used in these the make room for speakers, flywheels ect... , THIS is not for the novice!, You must completely disassemble the unit to keep the metal shavings from entering important parts like the gears motor ect... HOPE THIS HELPS !
Jack
rb-
Pulling that metal out of your loco's structure will negatively affect it's pulling capacity so you might want to add some heavier metal back, like lead. Keep it as low in the loco as you can. Or consider adding drive wheels which can accommodate traction tires. (Adding weight is better, in my opinion.
-- D