2-6-0 Quartering problem?

[Kasman727]

I have a Bachmann 2-6-0 that I have worked on but it seems to have  a significant wobble in the drive train.  I can't post a video here, but I posted on a Facebook site so show the problem.  I would appreciate anyone's thoughts on what I can do to try to remedy this or if anyone has suggestions on what the problem is and how to resolve it.  Is this a quartering problem on one of the drivers?

Video is located at:  https://www.facebook.com/groups/1408058259500198/      Search for my name, Kevin Spady.

Thanks for any help!

Kevin