As Jimmy said, LGB R3 turnouts have a notorious problem with the check rail on the curved side.
Having said that, it usually only gives the stock a bad jolt, and rarely causes a derailment.
Wobbly wheels aren't usually too much of a problem, so I'm with Greg - check the back to back first - one of the easiest ways is to line it up by eye with an LGB wheelset, then check that the bogie pivot is free to rock as well as pivot, and check that the wheels are running freely in the bogie sideframes - a little bit of side play always helps.