Need Help with Wobbly 9V Train Engine

[Bricknblue]

I only use the train when it's Christmas time because I don't have room for a set up. It's been running the holiday train set nicely for a few years, and the last few weeks. Then I noticed tonight it's been wobbling, and has a hard time moving along. One of the wheels seems to be really bad. Is there any way for me to fix the loose wheel without breaking it more?

[roamingstop]

This 9v repair thread might help

http://www.eurobricks.com/forum/index.php?showtopic=51366#entry1463356

[wondermonkey]

I'm sure you've done this but I always find pieces of string, dog hair, carpet, pine needles, etc. wrapped around one or both of the axles. There are other threads about opening the casing by cutting off the little tabs on the bottom. It's pretty straight-forward getting it open and maybe worth reading up on. A place to start anyway...