This is a 3d printed replacement set of 4 axles and 2 drive gears for a HO Scale Bachmann 4-8-4 gen 2.  Only 3 regular axles are required per locomotive as the 4th axle has the gear between the wheels.  A spare gear and a spare axle have been provided in the event one of them breaks when assembling.

Please note it's important to clean the inside of the axles and gear before inserting the wheel peg.  Leaving any 3D print residue inside may cause the new parts to split when pushed onto the wheels.  you may need to file the parts slightly to get the wheels to connect properly.

DO NOT FORCE the axels and gear into place. Refunds for broken axels or gears will not be provided as a spare has already been allocated in original shipment. 

when assembling the gs4 locomotive make sure you quarter the wheels or your locomotive will not work as expected.