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Axle - Structural component to which wheels, brakes and suspension are attached. Drive axles are those with powered wheels. Front axle is usually called the steer axle. Pusher axles are unpowered and go ahead of drive axles. Rear axles may be drive, tag or pusher types. Tag axles are unpowered and Reference: Truck Writers of North America (TWNA) Related Terms: Axle - kingpin axle | pusher axle | setback axle | spread axle | tag axle | tri-axle | trucking | Bogey - Assembly of two or more axles, usually a pair in tandem. Reference: Truck Writers of North America (TWNA)Related Terms: Bogey - bogie | trucking | Bogie - Assembly of two or more axles, usually a pair in tandem. Reference: Truck Writers of North America (TWNA)Related Terms: Bogie - bogey | trucking | Bridge Formula - A bridge protection formula used by federal and state governments to regulate the amount of weight that can be put on each of a vehicle's axles, and how far apart the axles (or groups of axles) must be to legally carry a given weight. Reference: Truck Writers of North America (TWNA)Related Terms: Bridge Formula - transportation | trucking | Converter Dolly - Auxiliary axle assembly equipped with a fifth wheel (coupling device), towed by a semitrailer and supporting the front of, and towing, another semitrailer. Reference: Truck Writers of North America (TWNA)Related Terms: Converter Dolly - dolly | trucking | Dolly - Auxiliary axle assembly equipped with a fifth wheel (coupling device), towed by a semitrailer and supporting the front of, and towing, another semitrailer. Reference: Truck Writers of North America (TWNA)Related Terms: Dolly - converter dolly | trucking | Driveline - All the components which together transmit power from the transmission to the drive axle(s). These consist of at least one driveshaft (propeller shaft) with a universal joint at each end. Reference: Truck Writers of North America (TWNA)Related Terms: Driveline - axle | drivetrain | engine | powertrain | truck | trucking | Drivetrain - All the components, excluding engine, which transmit the engine's power to the rear wheels: clutch, transmission, driveline and drive axle(s). Reference: Truck Writers of North America (TWNA)Related Terms: Drivetrain - powertrain | trucking | Fixed Tandem - Assembly of two axles and suspension that is attached to the chassis in one place, and cannot be moved fore and aft. Reference: Truck Writers of North America (TWNA)Related Terms: Fixed Tandem - sliding tandem | trucking | Gear Ratio - Number, usually expressed as a decimal fraction, representing how many turns of the input shaft cause exactly one revolution of the output shaft. Applies to transmissions, power takeoffs, power dividers and rear axles. Example: If 2.5 revolutions of an input shaft cause one revolution of the output shaft, the Reference: Truck Writers of North America (TWNA)Related Terms: Gear Ratio - truck | trucking | Gross Axle Weight Rating - Maximum weight an axle is rated to carry by the manufacturer. Includes both the weight of the axle and the portion of a vehicle's weight carried by the axle. Acronym: GAWR Reference: Truck Writers of North America (TWNA)Related Terms: Gross Axle Weight Rating - gross vehicle weight | trucking | Jack Brake - Device used to assist brakes in slowing the vehicle. The most common type of retarder on over-the-road trucks manipulates the engine's valves to create engine drag. (This type is commonly referred to as "Jake Brake" because the predominant manufacturer is Jacobs Vehicle Equipment Co.) Other types of retarders include Reference: Truck Writers of North America (TWNA)Related Terms: Jack Brake - retarder | trucking | Kingpin Axle - Pin around which a steer axle's wheels pivot. Reference: Truck Writers of North America (TWNA)Related Terms: Kingpin Axle - axle | kingpin trailer | trucking | Lift Axle - Extra, unpowered axle needed only when the vehicle is loaded, allowing it to meet federal and state vehicle weight standards. The lift axle is mounted to an air spring suspension that raises the axle when it is not required. Reference: Truck Writers of North America (TWNA)Related Terms: Lift Axle - axle | trucking | Powertrain - All the components, excluding engine, which transmit the engine's power to the rear wheels: clutch, transmission, driveline and drive axle(s). Reference: Truck Writers of North America (TWNA)Related Terms: Powertrain - drivetrain | trucking | Pull Trailer - Short, full trailer (supported by axles front and rear) with an extended tongue. Reference: Truck Writers of North America (TWNA)Related Terms: Pull Trailer - trailer | trucking | Pup Trailer - Short semitrailer, usually between 26 and 32 feet long, with a single axle. Reference: Truck Writers of North America (TWNA)Related Terms: Pup Trailer - trailer | trucking | Pusher Axle - Structural component to which wheels, brakes and suspension are attached. Drive axles are those with powered wheels. Front axle is usually called the steer axle. Pusher axles are unpowered and go ahead of drive axles. Rear axles may be drive, tag or pusher types. Tag axles are unpowered and Reference: Truck Writers of North America (TWNA)Related Terms: Pusher Axle - axle | trucking | Retarder - Device used to assist brakes in slowing the vehicle. The most common type of retarder on over-the-road trucks manipulates the engine's valves to create engine drag. (This type is commonly referred to as "Jake Brake" because the predominant manufacturer is Jacobs Vehicle Equipment Co.) Other types of retarders include Reference: Truck Writers of North America (TWNA)Related Terms: Retarder - jack brake | trucking | Rolling Radius - Tire dimension from center of the axle to the ground; measured with tire loaded to rated capacity. Used in calculating geared speed. Reference: Truck Writers of North America (TWNA)Related Terms: Rolling Radius - axle | trucking | Setback Axle - Front steering axle moved rearward from the generally accepted standard position. Advantages: Shorter turning radius and more of a vehicle's weight shifted to front axle. Reference: Truck Writers of North America (TWNA)Related Terms: Setback Axle - axle | trucking | Slider - Mechanism that allows a tandem axle suspension to be moved back and forth at the rear of a semitrailer, for the purpose of adjusting the distribution of weight between the axles and fifth wheel. Reference: Truck Writers of North America (TWNA)Related Terms: Slider - fixed tandem | sliding tandem | trucking | Sliding Fifth Wheel - Fifth wheel mounted to a mechanism that allows it to be moved back and forth for the purpose of adjusting the distribution of weight on the tractor's axles. Also provides the capability to vary vehicle combination lengths. Reference: Truck Writers of North America (TWNA)Related Terms: Sliding Fifth Wheel - fifth wheel | trucking | Sliding Tandem - Mechanism that allows a tandem axle suspension to be moved back and forth at the rear of a semitrailer, for the purpose of adjusting the distribution of weight between the axles and fifth wheel. Reference: Truck Writers of North America (TWNA)Related Terms: Sliding Tandem - fixed tandem | slider | trucking | Spread Axle - Tandem axle assembly spaced further apart than the standard spacing of 54 inches. The U.S. federal bridge formula favors trailer axles with an eight or nine foot spread by allowing higher weight than on tandems with standard spacing. Reference: Truck Writers of North America (TWNA)Related Terms: Spread Axle - axle | spread tandem | tandem axle | tandems | trucking | Spread Tandem - Tandem axle assembly spaced further apart than the standard spacing of 54 inches. The U.S. federal bridge formula favors trailer axles with an eight or nine foot spread by allowing higher weight than on tandems with standard spacing. Reference: Truck Writers of North America (TWNA)Related Terms: Spread Tandem - axle | spread axle | trucking | Tag Axle - Structural component to which wheels, brakes and suspension are attached. Drive axles are those with powered wheels. Front axle is usually called the steer axle. Pusher axles are unpowered and go ahead of drive axles. Rear axles may be drive, tag or pusher types. Tag axles are unpowered and Reference: Truck Writers of North America (TWNA)Related Terms: Tag Axle - axle | truck | trucking | Tandem Axle - Pair of axles and associated suspension usually located close together. Reference: Truck Writers of North America (TWNA)Related Terms: Tandem Axle - axle | spread axle | tandems | trucking | Tandems - Pair of axles and associated suspension usually located close together. Reference: Truck Writers of North America (TWNA)Related Terms: Tandems - axle | spread axle | tandem axle | trucking | Tractor (1) - Truck designed primarily to pull a semitrailer by means of a fifth wheel mounted over the rear axle(s). Sometimes called a truck tractor or highway tractor to differentiate from it from a farm tractor. Reference: Truck Writers of North America (TWNA)Related Terms: Tractor (1) - truck | trucking | Tri-Axle - Truck, tractor or trailer with three axles grouped together at the rear. Reference: Truck Writers of North America (TWNA)Related Terms: Tri-Axle - axle | tridem | trucking | Tridem - Group of three axles on a truck, tractor or trailer. Tridems are most common on European semitrailers. Reference: Truck Writers of North America (TWNA)Related Terms: Tridem - axle | tri-axle | trucking | Walking Beam Suspension - Type of truck and tractor rear suspension consisting of two beams, one at each side of the chassis, which pivot in the center and connect at the front to one axle of a tandem and at the rear to the other axle. Reference: Truck Writers of North America (TWNA)Related Terms: Walking Beam Suspension - truck | trucking |
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WWW Virtual Library of Logistics Ver 4, Sep, 1999, Matthew D. Cox, logistics@logisticsworld.com Sponsored by LogisticsWorld. Copyright © 1995, 1996, 1997, 1998, 1999 MDC, All rights reserved. |