The modern monster truck is just a four wheel drive truck rigged to be a dune buggy with tractor size wheels. The latest monster trucks have custom built tubular chassis, with four-link suspensions that provide up to four feet of travel. The engines are mounted just behind the driver, and are typically supercharged and have displacement of up to 575 cubic inches (9.42 litre), running on methanol for the extra kick.
The monster truck’s axles are sourced from either school buses or heavy-duty military trucks, which are modified to have a planetary gear reduction at the hub to help turn the tyres. All trucks have hydraulic steering in both rear and front—the front wheels controlled by the steering wheel and the rear wheels controlled by a toggle switch. The tractor tyres or Terra tyres typically measure 66”x43”x25.”
Monster trucks are built with many safety features, including three kill switches; two in the driver’s cab and one in the rear so that all electrical power can be shut off in case of a rollover. Drivers are seated in the center of a shielded cab, and are required to wear helmets and head and neck restraints, firesuits, and safety harnesses.