Abstract: A modular toy train truck assembly includes a frame having an integrally casted center plate and bolster plate connected to a pair of ornamental side frames that may be easily modified during the casting process to replicate various truck styles. Connected to the frame is a universal chassis comprised of a pair of wheel assemblies and a pair of bearing inserts whereby the wheel assemblies are journalled to the bearing inserts. Depending upon the style of truck, the side frames are provided with coils that are held in place by a flange integral with each insert. This unique design allows a modular truck frame to be easily retrofitted with a variety of accessories that may be attached to the truck frame by the customer.