re: GP38's

[gtwfan]

Hi all
     I have a new Bachmann GP38 in CN livery with DCC on board. It's making some weird noises and doesn't move very smoothly when using my Lenz DCC system. I can't tell if it's the drive train or the motor that's growling. My question is this, are the side frames and gear covers on the trucks all one piece? I'm trying to check to see if there are burrs on the gear sets and make sure they're lubed. I've looked at the exploded view on this site but can't tell if the truck and side frames are one piece or two. Thought I'd ask a question before I screw anything up . Also, any one have any experience with the NCE replacement decoder for this locomotive?
Thanks in advance    Gerry S.