Chassis

In the case of vehicles, the term rolling chassis means the frame plus the "running gear" like engine, transmission, drive shaft, differential, and suspension.

For commercial vehicles, a rolling chassis consists of an assembly of all the essential parts of a truck without the body to be ready for operation on the road.

In particular applications, such as school buses, a government agency like National Highway Traffic Safety Administration (NHTSA) in the U.S. defines the design standards of chassis and body conversions.

[6] An armoured fighting vehicle's hull[7] serves as the chassis and comprises the bottom part of the AFV that includes the tracks, engine, driver's seat, and crew compartment.

The chassis essentially functions as a more extensive pillar bedding, providing a metal-on-metal bearing surface that has reduced shifting potential under the stress of recoil.