Appreciate all the replies!
I learned that the volume resets to max every time you turn the locomotive on if you lower it with the remote, which is what I was doing.
Turns out if you use the screw under the coal load on the tender to lower the volume, it doesn't reset.
Turned the volume all the way off to confirm that it is indeed sound related, not mechanical.
Even on the lowest volume setting it makes that horrible sound, but much lower.
We took the locomotive apart and don't see any visible damage to the speaker.
I suppose it could be the soundboard itself, but we'll replace the speaker first and see if that helps.
Can anybody recommend a replacement speaker that we could swap out ourselves?
