Home » Training » Trailer Glossary Trailer GlossaryDoes trailer terminology have you confused? No problem! The Trailer Technician Trailer Glossary provides the definitions of commonly used terminology from the heavy-duty truck and semi-trailer industry. Glossary #7-Way AA-TrainActuatorAero SkirtsAggregate HopperAir BrakeAir DryerAir SpringAir TankAmerican Wire Gauge (AWG)Annual InspectionAnti-Lock Braking System (ABS)ApitongAxleAxle Weight BB-TrainBlink CodesBobtailBogieBolster PlateBolster Plate HeightBrake ActuatorBrake ChamberBrake ControllerBrake DragBrake FadeBrake ForceBrake Monitoring System (BMS)Brake StrokeBridge FormulaBrinell HardnessBulkhead CC-TrainCamberCenter-of-GravityChassis, ContainerClass 1 TruckClass 2 TruckClass 3 TruckClass 4 TruckClass 5 TruckClass 6 TruckClass 7 TruckClass 8 TruckClearance LightsClevisCommercial Driver’s License (CDL)Commercial Motor Vehicles (CMVs)Commercial Vehicle Safety Alliance (CVSA)Commercial Vehicle Safety Plan (CVSP)Commercial TrailerCompliance, Safety, Accountability Program (CSA)ConestogaConnector, BulletConnector, ButtConspicuity Tape (DOT Tape, Reflective Tape)ContainerContinuity TesterCrossmemberCurbsideCushion Foot DDepartment of Transportation (DOT)Diagnostic Trouble Code (DTC)Dielectric GreaseDock LockDollyDoor Hold BackDoor SealDoor, OverheadDoor, SwingDoublesDoubles, Rocky MountainDoubles, TurnpikeDriver Vehicle Inspection Report (DVIR)Drop and HookDrop Deck TrailerDry Van Trailer EElectronic Braking Systems (EBS)Electronic Control Unit (ECU)Electronic Logging Device (ELD)Extendable Double Drop TrailerExtendable Flatbed Trailer FFederal Motor Carrier Safety Administration (FMCSA)Federal Motor Vehicle Safety Standards (FMVSS)Fiberglass Reinforced Composite (FRC)Fiberglass Reinforced Plastics (FRP)Fifth WheelFifth Wheel HeightFifth Wheel Top PlateFixed TandemFlapsFlash CodeFlat RateFlatbed TrailerFloat TrailerFloor, CompositeFloor, LaminatedFloor, ShiplapFloor, Tongue & GrooveFoundation Brake GGalvanizedGladhandGooseneck TrailerGross Axle Weight Rating (GAWR)Gross Combination Weight (GCW)Gross Vehicle Weight (GVW)Gross Vehicle Weight Rating (GVWR)Ground Bearing HHarness, WiringHours of Service (HOS)HubodometerHydrogenated Nitrile Butadiene Rubber (HNBR) IICC Bumper JJackknifeJohnson Bar KKingpinKingpin LockKingpin Plate LLanding GearLash RingLess-Than-Truckload (LTL)Lift AxleLift GateLoad ConcentrationLoad LocksLong StrokeLowboy TrailerLumen MMROMulti Meter NNitrile Butadiene Rubber (NBR)Non-Ground BearingNose Cone OOff-RoadOhmOn-RoadOriginal Equipment Manufacturer (OEM)Out of Service (OOS)OutriggerOverhang PPayload CapacityPiggybackPigtailPintle HookPlacardPlatooningPounds Per Square Inch (PSI) Q RRear Impact Guard (RIG)Red TagRefrigerated Trailer (Reefer)RelayRemovable Gooseneck Trailer (RNG)Ride HeightRigid Fifth WheelRoadRailer TrailerRoadsideRoll AxisRoll CenterRub Rail SSAE J560SAE J1939Safety Measurement System (SMS)Sand ShoeScuff LinerSemi-TrailerShort StrokeSide RailSide SkirtsSidekit TrailerSlack AdjusterSlide TravelSliding Fifth WheelSliding TandemSmart TrailerSpecialty TrailerSpindleSpread AxleStandard Repair Time (SRT)Stationary Fifth WheelStep Deck TrailerStretch RGN TrailerStretch Single Drop Deck TrailerSuper SingleSuspensionSuspension, Air RideSuspension, Leaf Spring TTack WeldTandemTare WeightTautlinerTelematicsTerminal TractorThermal EventTire Load RatingTire Pressure Monitoring System (TPMS)Tone RingTowed Vehicle Weight (TVW)TractorTrailer TechnicianTread DepthTri-axleTriples UUnited States Department of Transportation (USDOT)Upper Coupler VVan TrailerVehicle Identification Number (VIN)Vehicle Maintenance Reporting Standards (VMRS)VIN TagVertical Load CapacityVolt WWattWheel BaseWheel EndWheel Speed SensorWheel Torque X YYard CheckYard JockeyYard Management System (YMS)Yard TractorYoke Z Click to share on Facebook (Opens in new window)Click to share on X (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pinterest (Opens in new window)Click to share on LinkedIn (Opens in new window)