My WBB GP30 quit running last night. It was going great until I decided to reverse it. Then... nothing. I think it's a connection problem, not a dead board because sometimes it will try to fire up but it won't move. When I took it off the track for a closer look I noticed one of the truck side frames is very loose. Pretty sure this is what's causing the problem but I can't see any obvious way to tighten it (middle going on old age eyeballs...). Anyone know how to tighten the side frames? I'd really prefer to fix this myself instead of sending it off for warranty work.

Thanks,
Ken