First I'll apologize for not reading all the post's. I had a new Legacy engine with a smoke problem and at that time was not aware of the "Don't open it up policy"
I talked to the guys at Lionel, may have been Mike I can't recall . He just said "TRY" not to do it again cause it'll void the warranty and gave me an RA to send it back.
Those guys know we mess around inside these things and most of us are savy enough to not just start rippin stuff apart.
But as complex as these gizmos are .,I'd just bite the bullet on this one and send it to Lionel then you'll know it's right when you get it back.
If someone has already said this then just call me Echo
Good Luck
David