| Glossary
of Truck Terminology |
| AERODYNAMICS
PACKAGE |
A
group of components consisting of the following:
roof mount wind deflector, side fairings, front
spoiler and fuel tank skirting. Also see individual
listing for each item. |
| AFTER
COOLER |
A
performance device found on diesel engines. |
| AIR
BAGS |
Pneumatic
air bags serving as springs. |
| AIR
BRAKE DRYER |
A
device that removes moisture from air-operated brake
systems. |
| AIR
FOIL |
see
WIND DEFLECTOR. |
| AIR
RIDE SUSPENSION |
A
series of air filled bags mounted on a tractor or
trailer suspension that provide a softer, more controlled
ride. |
| AIR
SLIDE FIFTH WHEEL |
A
fifth wheel that can be positioned remotely through
a control in the FIFTH WHEEL
cab of a tractor. Also see FIFTH
WHEEL. |
| ALUMINUM
DISC WHEELS |
see
DISC WHEELS. |
| ANTEATER |
A
generic description of a low profile, high aerodynamic
tractor. |
| ATTIC |
The
part of a van body which extends over the cab of
the truck. |
| AUXILIARY
TRANSMISSION |
Extra
transmission mounted behind the main transmission
to provide additional gear splits. |
| BANJO |
Rear
axle drive or differential housing. |
| BBC |
Front
bumper to back of cab dimension. Measured in inches. |
| BINDERS |
Lever-type
device used on trailers for securing cargo. |
| BLOWER |
A
turbo charger on diesel engines. |
| BOBTAIL |
Tractor
being driven without a trailer attached. Also a
straight truck. |
| BOGIE
|
Tandem
rear axle assembly (same as TANDEM
AXLE and DUAL DRIVE TANDEM). |
| BROWNIE
|
Auxiliary
transmission mounted behind the main transmission.
|
| BUDD
WHEELS |
See
DISC WHEELS. |
| BULKHEAD |
The
part of a trailer that extends vertically. |
| CAB |
The
part of the vehicle that encloses the driver and
operating controls. |
| CAB
OVER ENGINE |
See
COE. ENGINE |
| C
A DIMENSION |
The
distance from the back of the truck cab to the centerline
of the rear axle. Measured in inches. |
| CAMELBACK
SUSPENSION |
A
type of heavy-duty rear spring suspension. |
| CAB
PROTECTOR |
A
shield covering the rear of a cab, normally constructed
of steel, aluminum or mesh. |
| CLEARANCE
LIGHTS |
The
small lights found on each corner of a trailer and
on top corners of trucks and tractors. |
| CLASS
1-8 TRUCK |
Truck
with the following Gross Vehicle Weight (GVW):
| CLASS |
GVW |
CLASS |
GVW |
| 1 |
6,000or
less |
5 |
16,001
- 19,500 |
| 2 |
6,001
- 10,000 |
6 |
19,501
- 26,000 |
| 3 |
10,001
- 14,000 |
7 |
26,001
- 33,000 |
| 4 |
14,001
- 16,000 |
8 |
33,001
and over |
|
| COE |
A
truck or tractor designed with the engine under
the cab and having the provisions for the cab to
tilt forward on a pivot to allow access to the engine. |
| C
O F C |
Container on a (rail) flat car. |
| COMBINATION
VEHICLE |
An
equipment configuration which includes a separate
power unit combined with a trailer. Also known as
a TRACTOR-SEMI-TRAILER. |
| COMMERCIAL
TRAILER |
A
trailer used to handle freight in the transportation
of goods for TRAILER others:
excludes house trailers, light farm trailers, car
trailers, etc. |
| CONVENTIONAL
CAB |
Cab
in which the engine is mounted forward of the driver
compartment. |
| CROSS
MEMBER |
The
portion of frame on tractors and trailers that runs
at a right angle between the main and left and right
frame rails. |
| DAY
CAB |
A
non-sleeper tractor. |
| DAYTON
WHEELS |
see
SPOKE WHEELS. |
| DEAD
AXLE |
An
axle without any driving power. Also known as a
TAG AXLE. |
| DISC
WHEELS |
A
one-piece tire rim. Available in steel, chromed
steel, and aluminum. Also known as BUDD
WHEELS. |
| DOLLY |
An
auxiliary axle assembly having a fifth wheel. Used
for converting a semitrailer to a full trailer. |
| DOUBLE |
A
combination of two trailers pulled by a power unit.
Usually refers to a tractor pulling two 28' trailers.
Also see ROCKY MOUNTAIN DOUBLE
and TURNPIKE DOUBLE. |
| DRAG
AXLE |
See
TAG AXLE |
| DRIVE
AXLE |
Front
and/or rear axle connected to the power unit. |
| DROP
DECK TRAILER |
A
flatbed type trailer with a belly section the same
or lower than the TRAILER
height of the axle(s). |
| DRY
VAN |
A
trailer with an enclosed body; not refrigerated.
|
| DUAL
DRIVE TANDEM |
Two
axles having drive mechanisms connected to an engine
power TANDEM unit. Also see BOGIE
and TANDEM AXLE |
| DUMPER |
A
dump truck or dump body. |
| DUPLEX |
A
transmission having five speeds forward with a two-speed
auxiliary; thus giving ten speeds forward. There
are two shift levers on this transmission. |
| ENGINE
BRAKE RETARDER |
A device using engine compression to slow a vehicle
down, saving the vehicle's air operated brake system.
Available only with diesel engines. Also known as
a JAKE BRAKE. |
| EXTENDED
HOOD |
An
option or model of a Class 8 conventional truck
with a longer hood. The hood normally extends an
additional 12". F. E. T. Federal Excise Tax. Applied
to the purchase of all new medium (33,000 lb.) and
heavy-duty trucks, trailers, and equipment. |
| FIFTH
WHEEL |
A
device used to connect a semitrailer and a tractor.
May be stationary (fixed) or sliding. Also see AIR
SLIDE FIFTH WHEEL and MANUAL
SLIDE FIFTH WHEEL. |
| FIFTH
WHEEL
HITCH |
A
hitch mounted inside the bed of a pickup body and
used for gooseneck trailers or RV's. |
| FLAPS |
Large
rubber or other flexible material mounted behind
the rear wheels of tractors and trailers, to shield
against rocks or other objects being kicked up from
the tires. |
| FLAT
BED |
Either
mounted on a cab & chassis or a type of semitrailer,
this body has no sides and comes in various lengths.
It is usually constructed of steel or aluminum with
a wood plank base. |
| FLAT
TOP SLEEPER |
A
sleeper box whose height is flush with the top of
the tractor's cab. |
| FLOATATION
TIRES |
Over-width
tires with a cross-section greater than 14 inches.
Applicable only to construction vehicles. |
| FLOAT |
An
extendable flat bed or lowboy trailer. |
| FRONT
SPOILER |
Aerodynamic
aid attached to the lower front bumper |
| FUEL
TANK SKIRTING |
Aerodynamic
aid attached over the fuel tanks creating a flush
face surface between the cab and frame. |
| GLIDER
KIT |
A
cab and chassis with all components except the complete
drive train (engine, transmission, differential,
and rear axles). |
| GOOSENECK
TRAILER |
A
trailer pulled by a FIFTH
WHEEL HITCH. |
| GROSS
COMBINED VEHICLE WEIGHT (GCW) |
The
maximum allowable load for a tractor and trailer.
|
| GROSS
VEHICLE WEIGHT(GVW) |
The
maximum allowable fully laden weight of the vehicle
and its payload The most common classification method
used by manufacturers and states for trucks and
tractors. |
| HEADACHE
RACK |
A
protective device found behind the back window of
a truck or tractor. Is either attached to the frame
of a tractor or part of a truck's body. |
| HEAVY
DUTY TRUCK |
Truck
or tractor with a gross vehicle weight in excess
of 19,500 lb. (Class 6 - 8). |
| HIGH
CUBE VAN |
Combination
of a van front section and a box-like cargo section. |
| HIGH
TILT CAB |
See
COE. |
| HENDRICKSON
SUSPENSION |
A
walking beam rear suspension. Used primarily on
heavy duty construction type trucks. |
| HOT
SHOT |
A
light or medium duty tractor equipped with an after-market
sleeper. |
| IN-FRAME
MAJOR
OVERHAUL |
Diesel
engine overhaul performed in the vehicle. Includes
the replacement of main and thrust bearings, rod
bearings, cylinder liners pistons, and rings and
reconditioning of the cylinder head. |
| I
L S |
In
Lieu of Stock, i.e. a component or piece of equipment
on the vehicle which differs from the standard factory
equipment. |
| JAKE
BRAKE |
Jacobs
Engine Brake. See ENGINE
BRAKE RETARDER. |
| KING
PIN |
The
pin on a trailer that connects it to the fifth wheel
of the tractor. |
| KING
PIN PLATE |
The
large flat plate surrounding the king pin on a trailer. |
| KIT |
See
GLIDER KIT. |
| LADDER
RACK |
Commonly
found on light duty utility bed trucks. This rack
allows open storage from the back of the truck to
over the cab. |
| LANDING
GEAR |
The
small wheels mounted underneath the front of a semitrailer
to support the front when it is disconnected from
the tractor. |
| LIFT
GATE |
A
mechanism found on the rear of a truck body that
is used to load and unload heavy products. The gate
is rated in pound capacity and powered either hydraulically
or electrically. |
| LIGHT
DUTY TRUCK |
Truck
with a Gross Vehicle Weight of 10,000 lb. or less
(Class 1 & 2). |
|
LONG NOSE CONVENTIONAL |
A
truck or tractor with a front bumper to back of
cab dimensions (BBC) of 112" or more. |
| LOW
BOY |
A
trailer primarily used for hauling heavy machinery
with a detachable tongue and capacity rating in
tons. |
| MANUAL
SLIDE FIFTH
WHEEL |
A
fifth wheel that can be adjusted manually forward
or back along the frame of a tractor. Also see FIFTH
WHEEL and AIR SLIDE FIFTH
WHEEL. |
| MECHANICS
TRUCK |
A
utility bed attached to a cab and chassis that also
has other equipment attached. Other equipment may
include any combination of the following: an air
compressor, welder or small crane. |
| MEDIUM
DUTY TRUCK (Class 3 - 5) |
Truck
or tractor with a gross vehicle weight of 10,001
to 19,500 lb. |
| MICHIGAN
SPECIAL |
A
truck or tractor equipped with minimum front and
rear axle ratings of 18,000 and 44,000 lb. |
| MIXER |
A
truck mounted cement mixer. |
| NOSE
CONE |
Found
on the front of van bodies and dry van trailers,
this piece is attached to increase aerodynamics. |
| OWNER/OPERATOR
PACKAGE |
An
Over The Road tractor with the following equipment:
minimum 86" cab for COE's, 36" sleeper on conventionals,
air conditioning, dual aluminum fuel tanks, am/fm
stereo radio, and multicolored paint. Must also
have eleven of the following: carpet, headliner,
deluxe interior, power windows, high back seats,
full instrument gauges, dual air horns, spot lights,
visibility windows, step package, aluminum or chrome
bumper, stainless quarter fenders, dual heated stainless
steel mirrors, and/or chrome air inlets. |
| OUT-OF-FRAME
MAJOR
OVERHAUL |
Diesel
engine overhaul performed with the engine removed
from the vehicle. Includes all In-Frame repairs
with the addition of reconditioning the complete
lower end, including the crankshaft. |
| OVER
THE ROAD TRACTOR OR TRUCK |
A
vehicle equipped and in condition for long haul
operations. |
| PENTHOUSE |
A
sleeper unit and least 78" high with skylight type
windows. |
| PIGGYBACK |
The
transportation of highway trailers or containers
trailer bodies on rail cars specifically equipped
for the service. |
| PIG
TAIL |
The
electrical cable that connects the tractor unit
with the trailer. |
| PIPE
RACK |
Similar
to a LADDER RACK but can have
cylindrical tubes for enclosed storage. |
| POGO
STICK |
A
metal pole with springs mounted behind the cab that
support the air lines. |
| POWER
TRAIN |
The
group of components used to transmit engine power
to the wheels. Includes engine, clutch, transmission,
universal joints, drive shafts and rear axle gears
and shafts. |
| POWER
UNIT |
The
control and pulling vehicle for trailers and semi-trailers.
Also see TRACTOR. |
| P
T O |
Power
Take Off - a device that harnesses engine power
to operate mechanical accessories. |
| PUSHER
AXLE |
A
non-powered truck or tractor axle set in front of
powered axle. Also see TAG AXLE
and TANDEM AXLE. |
| RECAPS |
Tires
that have had the tread replaced. Also known as
Bandags. |
| REEFER |
Refrigerated
truck body, trailer or semitrailer. |
| ROCKY
MOUNTAIN DOUBLE |
A
combination vehicle consisting of a tractor, a 40'
- 48' trailer, and a shorter second trailer. Also
see DOUBLE and TURNPIKE
DOUBLE. |
| ROOF
MOUNT WIND DEFLECTOR |
See
WIND DEFLECTOR. |
| SADDLE
TANKS |
Fuel
tanks that are mounted along the frame just to the
rear of the cab. |
| SEMI
-TRAILER |
Truck
trailer equipped with one or more axles and constructed
so that the front end rests upon a truck tractor. |
| SET
BACK FRONT AXLE |
Front
axle located purposely toward the rear for increased
load distribution. |
| SHORT
NOSE CONVENTIONAL |
A
truck or tractor with front bumper to back of cab
dimension (BBC) of 95" or less. |
| SIDE
FAIRING |
Aerodynamic
aid attached to rear sides of a truck or tractor
creating a flush surface from the vehicle to the
trailer. |
| SINGLE
SCREW |
A
tractor with a single driven axle. |
| SIX
BY SIX |
(Written
6X6), a tractor having six wheels driving (3 axles),
i.e. a tandem rear-end with driving front axle. |
| SLEEPER
SIZE |
The
front to rear dimension in inches. Used on Conventional
Cab Tractors. |
| SLIDING
REAR
AXLE |
A
trailer axle that can move forward or back along
the frame rails. |
|
SPOKE WHEELS |
Two-piece
cast iron and steel tire rims. Also known as DAYTON
WHEELS. . |
| STACKS |
Vertical exhaust pipes on a tractor. |
| STAKE
BED |
A
flat bed with vertical posts and horizontal slates,
usually made of wood or steel. |
| STAND
UP SLEEPER |
A
tall sleeper box similar to a PENTHOUSE
SLEEPER without the skylight windows. |
| STEEL
DISC WHEELS |
See
DISC WHEELS. |
| STEP
TANKS |
Fuel
tanks that integrate a step for access to the cab. |
| STEP
VAN |
A
complete body built on a forward control chassis,
referred to as a bread truck or a UPS type vehicle.
|
| STRAIGHT
TRUCK |
A
vehicle with the cargo body and cab mounted on the
same chassis. |
| SUPER
SINGLES |
Very
wide tires that take the place of dual wheels on
each axle. A rear tandem axle truck normally has
8 tires, however, if equipped with super singles
it will have only 4. Usually found on mixers or
dumps. |
| TAG
AXLE |
A
non-powered truck or tractor axle set behind a powered
axle. Also known as TRAILING
TANDEM. |
| TANDEM
AXLE |
Two
axles operated from a single suspension. Also see
BOGIE and DUAL
DRIVE TANDEM AXLE. |
| T
O F C |
Trailer
On (rail) Flat Car. |
| TRACTOR |
A
truck cab and chassis without a body and equipped
with a fifth wheel. Used for pulling a semitrailer.
|
| TRACTOR
SEMITRAILER |
A
combination vehicle consisting of a power unit (tractor)
and semitrailer. |
|
TRAILER |
A
vehicle designed without motive power to be drawn
by anther vehicle. |
| TRAILER
GRAIN BED |
An open top, high-sided body used for transporting
grain. These normally are equipped with a lift or
bottom dump. |
| TRAILING
TANDEM AXLE |
See
DUAL DRIVE TANDEM AXLE, TAG
AXLE, and TANDEM AXLE. |
| TRI-AXLE
TANDEM |
Three
axles operated from a single suspension. |
|
TRUCK |
A
motor vehicle designed to carry an entire load.
It may consist of a chassis and body, a chassis,
cab and body, or be of integrated construction so
that the body and chassis form a single unit. |
| TURNPIKE
DOUBLE |
A
combination vehicle consisting of a power unit (tractor)
and two trailers DOUBLE of at least 40' in length.
See also DOUBLE and ROCKY
MTN. DOUBLE. |
| TWIN
SCREW |
A
double rear axle drive unit. |
| TWIN
TRAILER |
A
short semitrailer under 29' designed to be operated
as part of a combination vehicle with a tandem trailer
of similar length. |
| TWO
SPEED AXLE |
A
rear axle with two ratios and a mechanism for selection.
|
|
UTILITY BED |
A
truck bed attached to the cab and chassis that has
compartments and toolboxes accessible from the exterior
of the bed. The interior is normally open but can
be equipped with an optional enclosure. |
| VISIBILITY
WINDOW |
A
window in the lower portion of the door, which enables
the operator to look down on traffic. |
| WEST
COAST MIRRORS |
Large
rear view mirrors on both sides of the cab. |
|
WEST COAST RIG |
A
special light weight truck or tractor. |
|
WET LINE KIT |
A
hydraulic pump and reservoir assembly used to operate
a dump trailer. |
| WHEEL
BASE |
The
distance between the centerlines of the front and
rear axles. For trucks or trailers with tandem or
tri-axles, the centerline is midway between the
rear axles. |
| WHEEL
POWER |
The
total number of axles of a power unit (X) the number
of wheels powered and multiplied by 2. Example is
3 axles, 2 of which are power is listed as 6x4. |
| WIND
DEFLECTOR |
Aerodynamic
aid attached to the roof of a truck, or tractor
creating an air stream over the trailer. Also see
AIR FOIL. |
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