Problem with Centennial Amtrack Diesel 951 derailing

[RMT]

Was given a set of Centennial Amtrak trains.  Set has a diesel / electric engine marked Amtrak 951.  Each truck has six wheels.  With my turnouts set to straight there  is a tendency for the front wheel truck to pass correctly over a turnout going straight but the back wheel truck to derail trying to turn inward even though the turnout is set for straight.  If I turn the engine around the front wheel truck will try to turn inward even though the turn out is set for straight.  I have five other engines all with four wheel trucks that have no problem on the turnouts.  Has anyone else encountered this problem and was there a fix?  Previous information from this site was very helpful.  Hope you guys can do it again.  Thanks.       

[taz-of-boyds]

Hello,

One quick check, if you have an NMRA standard gauge for N scale, check the gauging of the wheels on the loco.  They should match the wheel gauge exactly.

Another standard item to check is the seating of the closed point against the fixed rail, it should be reasonably smooth, or it could require some filing or grinding.

I will see if I can add some graphics later...

All the best,
Charles