Lionel 6-28567 running problems

I don't know what that is, but it ain't normal!

I have a GP-7 and GP-9 of the same vintage, and they sure don't do that!

You have no choice but to pull off the shell. Something must be hitting a spinning part. I've never heard anything like that.

Rod Miller

I can not pick the noise but will throw this out.  Those engines had super crappy traction tires and some were so fat they would drag inside the side frames.  Give that a look and see if you are there.  If in doubt, pull the side frames or cut the tires off.  I have many Lionel diesels and the first thing I do when they come out of the box is to introduce them to Mr X-Acto. I then put on the much better MTH tires..  Those engines you have are super runners.

As Marty says could be the traction tires for the stuttering. Have you run it with the cab off? Worked on an F3 that someone had somehow got the either the cab motor shield or antenna mount, I can't recall exactly what part it was right now, to rub on the flywheel.

As Marty pointed out, I would definitely check the traction tires; have seen quite a few from that run where TT rubbed against the side frames and actually threw ground up residue into the gears; replace them with MTH tires as suggested.  Falcon 70

I have an early Legacy steamer that sounded like that. It turned out to be some wires hitting the slots in the flywheel. Moved the wires and it was fine.

Steve, I have seen that one a few times.