I have a Bachmann large scale loco that binds up on curves. Runs fine on staright aways,but as soon as it goes in to curves it stops. Seems like rear shaft is binding up. How do I rectify this situation? How do I know which way to turn drive shaft?
SgtMaj
Best guess is that you have an early version that does not have drive-line isolation between the trucks. There is a retrofit drive-line available (sometimes) from Bachmann that solves this issue. It has a clutch like slip fitting so that only one of the trucks drives the piston's mechanism and that way the two power trucks are not trying to fight each other.
Can't say for sure that this is your problem, but it sure sounds like it!?!?
If that is in fact your problem, then likely this is the part that you need to replace your rear drive shaft:
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_641&products_id=8300
I agree with Stokerman and there is a parts store sale going on right now and the part shows available. A simple test is to remove the rear drive shaft and run the loco if it does not bind you can run it while you wait for the part. Loco Bill