| A | B |
|---|
| Antilock Braking System | computer, sensors and solenoid valves which together monitor wheel speed and modulate braking force if wheel lockup is sensed during braking |
| axle | • structural component to which wheels, brakes and suspension are attached |
| blind spot | areas around a commercial vehicle which are not visible to the driver either through the windshield, side windows or mirrors |
| bobtail | tractor operating without a trailer; also refers to straight truck |
| cargo weight | combined weight of all loads, gear and supplies on a vehicle |
| Commercial Driver’s License | license which authorizes you to operate commercial motor vehicles and buses over 26,000 pounds gross vehicle weight |
| center of gravity | weight center or balance point of an object, such as a truck body; determines optimum placement of truck bodies on chassis |
| chassis weight / | weight of the empty truck, without occupants or load |
| converter dolly / dolly | auxiliary axle assembly equipped with a fifth wheel; coupling device towed by a semitrailer and supporting the front of, and towing, another semitrailer |
| driveline | all the components which together transmit power from the transmission to the drive axle(s); at least one driveshaft (propeller shaft) with a universal joint at each end |
| drivetrain / powertrain | all the components, excluding engine, which transmit the engine’s power to the rear wheels: clutch, transmission, driveline and drive axle(s) |
| fifth wheel | coupling device attached to a tractor or dolly which supports the front of a semitrailer and locks it to the tractor or dolly |
| grade | steepness of a grade, expressed as a percentage (example: a vehicle climbing a 5% grade rises 5 feet for every 100 feet of forward travel) |
