Bachmann Plus Class J 4-8-4

[cmsluss]

Greetings -

I have a Bachmann Plus (White Box edition) 4-8-4 Class J.  Recently the locomotive has been slowing in turns, then returning to running speed on straight track.  I cleaned the axles (thinking the engine wasn't getting sufficient power) and I cleaned the portion of the split frame that makes contact with the axles and there was no improvement.  I tried running the locomotive with just the frame and drivers (no shell, no plastic chassis) and the running improved in turns.  I have a Bachmann Niagara 4-8-4, and it runs flawlessly.  Any suggestions would be greatly appreciated.

Thank you!

[brokenrail]

How tight are your turns in radius? If the turns are too tight there is not a problem with your loco .The problem is in your turns.Locos with the 4 driver arrangement will bind in tight curves since they and all locos have no differential  just solid axles.If it runs well on the straight section .This is your problem.Large locos that do not articulate need larger radius curves.
Johnny Adam

[RAM]

Since you have two 4-8-4s and only one slows down I would check to see if the drivers on the J are too wide.