List of railroad truck parts

A bogie or railroad truck holds the wheel sets of a rail vehicle.
Axlebox.
An "axle box", also known as a "journal box" in North America, is the mechanical subassembly on each end of the axles under a railway wagon, coach or locomotive; it contains bearings and thus transfers the wagon, coach or locomotive weight to the wheels and rails; the bearing design is typically oil-bathed plain bearings on older rolling stock, or roller bearings on newer rolling stock.
Plain bearings are now illegal for interchange service in North America. As early as 1908 axle boxes contained a set of long cylindrical rollers allowing the axle to rotate. It was also used on steam locomotives such as the Victorian Railways A2 class, the LMS Garratt, the LSWR 415 class, and the GCR Class 1.
Center pin.
A large steel pin—or rod—which passes through the center plates on the body bolster and truck bolster. The truck turns about the pin, and stress is taken by the center plates.
Center plate.
One of a pair of plates which fit one into the other and support the car body on the trucks allowing them to turn freely under the car. The one on the truck may also be called center bowl.
Truck side frame.
The frame at either side of the truck.
Truck bolster.
Each truck has a bolster—a transverse floating beam—between the side frames. It is the central part of every truck on which the underframe of the railcar or railroad car is pivoted through the center pivot pin.
Side bearing.
There is one side bearing located on each side of the centerplate on the truck bolster.