T & C
Transmission and Chassis Division
TACH
Abbreviation for tachometer, an instrument that
indicates engine revolutions per minute.
TACHOGRAPH
A tachograph is a device which monitors and records
various operating characteristics of a vehicle, including vehicle speed, total
miles elapsed, engine RPM, total number of engine revolution-, ignition time
on, vehicle movement time, and other data at the discretion of the owner.
TACHOMETER
A device, located on the instrument panel, that
indicates the revolutions per minute of the engine's crankshaft.
TACTIC
Actions taken by a traffic unit to avoid a
hazardous situation; steering, braking, accelerating, etc. to avoid a collision
or other accident. Often called an
evasive maneuver.
TAG AXLE
A non-driven (dead) axle installed behind the drive
axle(s) to increase the permissible gross weight, and consequently the payload.
Also termed "trailing axle."
TAKEOFF ANGLE (FALL OR VAULT)
The takeoff angle is the angle between the
trajectory, or path, of the car and the horizontal in a fall or vault.
TAKEOFF POINT , FALL OR VAULT)
The takeoff point is the point at which ú vehicle
leaves the ground in a fall or vault.
TAKEOFF SPEED
The takeoff speed of a vehicle which plunges off a
precipice, embankment, terminal point in the road, bridge, or for some reason
travels off the road and through the air, is the speed at which the vehicle
leaves the surface.
TAMPER
A power driven machine for compacting ballast under
ties.
TANDEM AXLE
A tandem axle set comprises two axles mounted
closely enough together that they are treated as one axle for purposes of
kinematic analysis or for purposes of loading analysis. The distance separation varies among the
states: in the Federal Weight Law axles closer than 9 feet are designated as
tandem axles.
TANDEM DRIVE
Two-axle drive combination.
TANGENT
A line that touches a curve at only one point and
is perpendicular to the radius at that point; a term used to describe a
straight offset method.
TANK CAR / TRAILER
A semi trailer consisting of a metal tank for
carrying liquid or dry bulk. Also
called a tanker.
TANK DOME
A vertical cylinder attached to the top of a tank
car. It permits the tank proper to be
filled to full cubical capacity, which would be impossible if there were no
allowances for expansion in the dome.
TANKER
See tank trailer.
TAPE DRAWING
An outline of a car made with black
pressure-sensitive tape, which can be easily seen, removed, and changed. Most
often depicts the side elevation.
TAPER
Cone-shaped object or form.
TARE WEIGHT
(1) As applied to a loaded motor vehicle, tare weight
is the weight of the vehicle exclusive of its contents. (2) Also refers to the weight on a container
and or the material used for the container for packing the merchandise to be
shipped.
TEAM TRACK
A track on which cars are placed for the use of the
public in loading or unloading freight.
TECHNICAL FOLLOW-UP
Collection of additional facts from any source and
organization and preliminary study of all available data relating to a traffic
accident; level 3 of accident investigation.
TECHNICAL PREPARATION
Delayed traffic accident data collection and
organization for study and interpretation.
The data collected are essentially factual. Technical preparation includes making additional measurements and
photographs, preparing maps and diagrams, simple speed estimates, matching
damage areas, and making experiments to obtain specific data.
TEMPER
Heating and cooling of metal at desired rate to
obtain desired strength or hardening properties.
TEMPLATE
An accurate surface profile taken from a blueprint
or portion of a model to be duplicated. Can be made of cardboard, plastic,
Masonite, plywood or metal, depending on proposed.
TEN-WHEELER
Three-axle truck having ten wheels.
TERMINAL
A building for the handling and temporary storage
of freight as it is transferred between trucks, i.e., from a city pick up to a line haul truck.
TERMINAL CARRIER
The line haul motor carrier making delivery of a
shipment at its destination Terminal
carrier means the last or final carrier.
TEST LAMP
A device used to check an electrical circuit for
problems.
TEST MATRIX
An organized array of tests based on many variable
conditions and covering a complete given range.
TESTIMONY
Evidence given by a competent witness under oath or
affirmation.
TFE
(Targets for Excellence) document to define GM
quality expectations and to specify the supporting evidence that is required
from both internal and external suppliers. TFE consists of six major evaluation
areas: 1) Continuous Improvement; 2)
Leadership; 3) Quality; 4) Cost; 5) Delivery; 6) Technology
TFU
Tool Follow Up Sheet, record of tools forecast for
body program.
THEME SKETCH
A quick sketch to get an idea on paper; precedes a
rendering.
THERMOSTAT
Device in cooling system to maintain water
temperature within a definite range.
THREAD WIDTH
Distance between the centerline of front or rear
tires measured at the ground.
THREE PIECE RIM
A three piece rim is a type of wheel used on
trucks. The rim is made up of three
pieces, the pieces being called the rim base, the side tins, and the lock rings
THREE POINT RESTRAINT
A lap and shoulder belt.
Throttle (% open)
Throttle position expressed as a percent where 0% is fully closed and 100% is open wide. ( Detroit )
THROTTLE PLATE
The throttle plate is the circular (or nearly
circular) plate in the throat of the carburetor which controls the volume of
the air-fuel mixture delivered to the engine.
The throttle plate is caused to rotate in the throat by motion of the
throttle linkage.
THRUST
The force against a traffic unit considered to be
concentrated on a particular point on that unit at any instant during a
collision.
TIE PLATE
A metal plate at least six inches wide and long
enough to provide a safe bearing area on the tie, with a shoulder to restrain
outward movement of the rail.
TIE ROD
The tie rod in a steering system is a rod connected
at one end to the drag link and at the other end to the steering knuckle. The tie rods, drag link idler arm and
steering knuckles comprise the steering linkage.
TIER I SUPPLIER
Supplier who manufactures and sells product
directly to Automotive OEMs.
TIER II SUPPLIER
Supplier who manufactures and sells products to a
Tier I supplier to combine with other products for the Automotive OEMs.
TIG WELDING
Tungsten inert gas arc welding uses a
non-consumable tungsten electrode with the weldment shielded from contamination
by a jet of inert gas.
TIGER STRIPES
Vertical stripes predominantly observed in quarter
panels and doors made of draw quality material requiring flex rolling. Flex
roll mark appears each time coil is stopped for cutoff of blank.
TILT CAB
COE with facility to tilt cab forward for
accessibility.
TIME TABLE
The authority for the movement of regular trains
subject to the rules. It contains
classified schedules with special instructions relating to the movement of
trains and engines.
TIRE AXIS SYSTEM
The origin of the tire axis system is the center of
the tire contact. The X 1-axis is the
intersection of the wheel plane and the road plane with a positive direction
forward. The Z 1-axis is perpendicular
to the road plane with a positive direction downward. The Y 1-axis is in the road plane, its direction being chosen to
make the axis system orthogonal and right-hand.
TIRE FOOTPRINT
The tire footprint is the part of the tire which is
in contact with the road.
TIRE FORCES :
Aligning Stiffness (aligning torque stiffness)
TIRE FORCES :
Aligning Stiffness Coefficient (aligning torque
coefficient)
TIRE FORCES :
Aligning Torque (Aligning Moment) (M z)
TIRE FORCES :
Braking (driving) Squeal
TIRE FORCES :
Braking (driving) Stiffness
TIRE FORCES :
Braking (driving) Stiffness Coefficient
TIRE FORCES :
Braking Force
TIRE FORCES :
Braking Force Coefficient
TIRE FORCES :
Braking Torque
TIRE FORCES :
Braking Traction Coefficient
TIRE FORCES :
Camber Force (Camber Thrust)
TIRE FORCES :
Camber Stiffness
TIRE FORCES :
Camber Stiffness Coefficient (camber
coefficient)
TIRE FORCES :
Central Force
TIRE FORCES :
Conicity Force
TIRE FORCES :
Cornering Squeal
TIRE FORCES :
Cornering Stiffness
TIRE FORCES :
Cornering Stiffness Coefficient (cornering
coefficient)
TIRE FORCES :
Drag Force
TIRE FORCES :
Driving Force
TIRE FORCES :
Driving Torque
TIRE FORCES :
Driving Traction Coefficient
TIRE FORCES :
First Order Lateral Force Variation
TIRE FORCES :
First Order Radial Force Variation
TIRE FORCES :
Harshness
TIRE FORCES :
Lateral Force
TIRE FORCES :
Lateral Force Coefficient
TIRE FORCES :
Lateral Force Offset
TIRE FORCES :
Lateral Force Variation
TIRE FORCES :
Lateral Traction Coefficient
TIRE FORCES :
Normal Force (F z)
TIRE FORCES :
Overturning Moment (M x)
TIRE FORCES :
Peak-to-Peak (total) Lateral Force Variation
TIRE FORCES :
Peak-to-Peak (total) Tidal Force Variation
TIRE FORCES :
Peak-to-Peak Lateral Tire Run-Out
TIRE FORCES :
Peak-to-Peak Lateral Wheel Run-Out
TIRE FORCES :
Peak-to-Peak Loaded Radial Tire Run-Out
TIRE FORCES :
Peak-to-Peak Radial Wheel Run-Out
TIRE FORCES :
Peak-to-Peak Unloaded Radial Tire Run-Out
TIRE FORCES :
Ply Steer Force
TIRE FORCES :
Radial Force Variation
TIRE FORCES :
Rolling Resistance Force
TIRE FORCES :
Rolling Resistance Force Coefficient
TIRE FORCES :
Rolling Resistance Moment (M y)
TIRE FORCES :
Roughness
TIRE FORCES :
Sizzle
TIRE FORCES :
Slap
TIRE FORCES :
Sliding Braking Traction Coefficient
TIRE FORCES :
Slip Angle Force
TIRE FORCES :
Squeal
TIRE FORCES :
The external force acting on the tire by the road
having the following components:
Longitudinal Force (F x): The
component of the tire force vector in the X' direction.
TIRE FORCES :
Thump
TIRE FORCES :
Tire Force and Moment Stiffness
TIRE FORCES :
Tire Moments:
The external moments acting on the tire by the road having the following
components:
TIRE FORCES :
Tractive Force
TIRE FORCES :
Tread Noise
TIRE FORCES :
Vertical Load
TIRE FORCES :
Wheel torque (T)
TIRE FRICTION MARK
A tire mark made when a slipping or sliding tire
rubs the road or other surface; skid marks; yaw marks; acceleration scuffs and
flat tire marks.
TIRE LATERAL LOAD TRANSFER
The vertical load transfer from one of the front tires
(or rear tires) to the other that is due to acceleration, rotational, or
inertial effects in the lateral direction.
TIRE LATERAL LOAD TRANSFER DISTRIBUTION
The distribution of the total tire lateral load
transfer between front and rear tires expressed as the percentage of the total.
TIRE LONGITUDINAL LOAD TRANSFER
The vertical load transferred from a front tire to
the corresponding rear tire or vice versa that is due to acceleration,
rotational, or inertial effects in the longitudinal direction.
TIRE MARK
A mark on a road or other surface by a tire on a
vehicle; tire friction mark, imprint.
TIRE OVERALL WIDTH
The width of the unloaded new tire, mounted on
specified rim, inflated to the normal recommended pressure, including
protective rib, bars, and decorations.
(See Tire and Rim Association Year Book.)
TIRE RATE
(static)
The static rate measured by the change of wheel load per unit vertical
displacement of the wheel relative to the ground at a specified load and
inflation pressure.
TIRE SECTION HEIGHT
Half the difference between the tire outside
diameter and the nominal rim diameter.
TIRE SECTION WIDTH
The width of the unloaded new tire mounted on
specified rim, inflated to the normal recommended pressure, including the
normal side walls but not including protective rib, bars, and decorations. (See Tire and Rim Association Year Book.)
TIRE TRACK
A mark left by a rotating tire being operated over
a soft material, wet pavement, or material, or over heated asphalt. The tire tread pattern will show plainly.
TIRES, BELTED BIAS
Body plies are same as those for bias tires. In
addition, tires have belt plies that constrict the diameter and give greater
rigidity to the tread. Belts are
heavier construction and the cords lie in a more circumferential direction than
breakers on bias tires.
TIRES, BIAS
Body ply cords lie in a diagonal direction from
bead to bead. Tires may also have
narrow plies under the tread, called breakers, with cords that lie in
approximately the same direction as the body ply cords.
TIRES, RADIAL
Body ply cords are placed perpendicularly across
the tread from bead to bead. In
addition, radial tries have belt plies that run circumferentially around the
tire, under the tread. They construct
the radial ply cords and give rigidity to the tread, resulting in less rolling
resistance which gives better fuel economy.
TIRES, WIDE BASE
Same diameter as conventional tires, but have a
wider base that provide greater ground contact. Sometimes used to replace dual tires, resulting in cost and
weight savings.
TOE PAN
First break in the underbody between normal floor
surface and front-of-dash. Usually roughly parallel to bottom of occupant's
foot.
TOE-IN
The amount of inward tilt on most-forward part of
front wheels relative to centerline of fore and aft track.
TOE-OUT
Opposite Toe-In
TOGGLE PRESS
A mechanical press of two or three slides actuated
by toggle joints on the outer and crank shafts on inner slide or platen used
for toggle drawing. Is often referred to as a draw press.
TOLERANCE
Permissible variation in dimension, weight,
tic. For example, some states allow a
tolerance in their maximum truck weight limits.
TONGUE
The tongue of a trailer is the extension forward of
the trailer on which is mounted the hitch.
The term is applied chiefly to trailers designed to be towed by
automobiles.
TONGUE LOAD
The tongue load is the force transmitted by the
hitch to the tongue of a trailer.
TON-MILE
A unit of measure.
The movement of a ton of freight one mile. Ton-miles are computed by
multiplying the weight in tons of each shipment transported by the distance
hauled.
TONNAGE
Number of tons.
TOOL TRAIN
(Slang) Wreck train used for cleaning up
derailments
Top Gear
The lowest ratio between Engine Speed and Road Speed. This value is set in the DDEC engine calibration file. It can be changed with the ProLink Diagnostic Data Reader or Detroit Diesel Diagnostic Link software. ( Detroit )
Top Gear -1
The second lowest ratio between Engine Speed and Road Speed. DDEC learns this ratio by monitoring Engine Speed and Road Speed as the vehicle moves. The date upon which the ratio was learned is recorded and displayed on the Vehicle Configuration report. ( Detroit )
Top Gear Cruise
The condition in which the vehicle was in Top Gear ~d in Cruise at the same time. ( Detroit )
Top Gear Distance
Distance traveled while in Top Gear. ( Detroit )
Top Gear Economy
Top Gear divided by Top Gear Fuel. ( Detroit )
Top Gear Fuel
Fuel consumed while driving in Top Gear. ( Detroit )
Top Gear Percentage
Top Gear Time divided by Driving Time ( Detroit )
Top Gear Time
Time accumulated during top gear driving in HH:MM:SS format. ( Detroit )
TORQUE
The product of the force and the perpendicular distance from the axis of rotation to the line of action of the force.
TORQUE BALANCE
Effectiveness Balance - That condition of design or
adjustment where each pair of brakes on the axles of a vehicle or combination
vehicle develop, at the same applied pressure, that proportion of torque
consistent with the manufacturer's load rating of the axle. For purposes of
interchange, this torque should be sufficient to develop 9 fpsps deceleration
when 42 psi air is applied to the brake chambers when the axle is at rated
load.
TORQUE BOX
Usually refers to a reinforced area of a frame
which transmits torque loads.
TORQUE CONVERTER
A hydraulic drive which transmits power with
ability to change torque.
TORQUE RODS
See stabilizers.
TORQUE-ARM CENTER IN BRAKING
The instantaneous center in a vertical longitudinal
plane through the wheel center about which the wheel moves relative to the
sprung mass when the brake is locked.
TORQUE-ARM CENTER IN DRIVE
The instantaneous center in a vertical longitudinal
plane through the wheel center about which the wheel moves relative to the
sprung mass when the drive mechanism is locked at the power source.
TORQUE-ARM RADIUS
The horizontal distance from the torque-arm center
to the wheel center.
TORQUE-MOMENT
A measure of the effectiveness of a force in
producing rotation about the axis.
TORSION BAR
A torsion bar is an element of a suspension system
performing the same function as a spring.
A torsion bar is a long straight rod secured at one end to the chassis
of the vehicle and it the other end to a lever arm. By twisting the lever arm around the axis of the rod, a force is
developed at the end of the lever arm.
As installed in the vehicle, the force is used to support the vehicle,
and the twisting of the rod performs the "springing" function of the
torsion bar.
TORSION SPRINGS
Spring effect developed through torsional stress in
steel rod(s).
TORSIONAL SHAKE
A mode of vibration involving twisting deformations
of sprung mass about the vehicle x-axis.
TORSO LINE
Line parallel to the small of the manikin's back
through the "H" point.
TORSO TEMPLATE
A two-dimensional plastic template of the male
manikin used to establish the "T" point or head room when designing
the body interior package.
Total Alerts
Number of engine diagnostic alerts that occurred. Up to the last five check engine alerts and the last five stop engine alerts are saved and may be reported on the Alerts report. ( Detroit )
Total static deflection of a loaded suspension
system is the overall deflection under the static load from the position at
which all elastic elements are free of load.
TOTAL STOPPING DISTANCE
Total stopping distance is the distance traveled by
the vehicle from the moment the driver first detects a hazard until the vehicle
comes to rest.
TOW BAR
Bar or V-shaped device attached to the chassis of a
trailer dolly or front axle.
TOWED VEHICLE
A motor vehicle that was involved in an accident
and removed from the scene by means other than its own power.
TOWER
Building of sufficient height erected along
right-of-way to permit maximum viewing.
May house yard master, switch lever operator, block operator, or
dispatcher.
TOW-IN
The amount of distance which the front of the front
wheels are closer together than the rear of the wheels. Front tires are toed-in to improve steering
and increase tire life.
TPO
Thermoplastic olefin - type of plastic used for
injection molded plastic parts.
"T" Point
A point located on the head of the torso template
which represents 30 inches of effective headroom when the template is located
in the correct seated position.
TPU
Thermoplastic urethane - type of plastic used for
injection molded plastic parts.
TQE
(Total Quality Excellence) is Ford's highest
recognition of full-service suppliers. It represents a superior level of
excellence and continuous improvement in everything suppliers do to meet Ford
customer's needs and expectations.
TQM
(Total Quality Management) A process approach to
quality which holds each person in the organization responsible for their
personal output.
TRACK
1) The distance on the ground between the center of
the tire tread on one side of the vehicle to the center of the tire tread on
the opposite side. 2) The space between
the rails and space of not less than 4' outside each rail.
TRACK CAR
A self propelled car including; Burro cranes,
Highway rail cars, Detector cars, Weed burners, Tie tampers, and other similar
equipment. This type of equipment may
not operate signals or shunt track circuits.
TRACK CHANGE
The change in wheel track resulting from vertical
suspension displacements of both wheels in the same directions.
TRACK CIRCUIT
An electrical circuit which includes the rails and
wheels of the train. Used for
controlling signaling devices (fixed signals as well as flashers and gates at
crossings).
TRACK WIDTH
The distance between the front wheels and/or the
distance between the rear wheels.
Measured from the center of the tire along the lateral axis.
TRACK, AXLE
Distance between centerlines or tire tread at
ground on front or rear axles.
TRACKING
Marks made when tires roll through puddles,
run-off, or splatter and, becoming wet, leave tire prints on the pavement as
they roll on.
TRACTION FORCE
The adhesive friction of a body, such as a tire, on
a surface, such as a roadway, that keeps the body from slipping on the
surface. Traction breaks and slipping
begins when another force, such as breaking force and centrifugal force exceeds
traction force.
TRACTION GRADE (OF A TIRE)
The traction grade represents a tire's ability to
stop on wet pavement as measured under controlled conditions on specified
government test surfaces of asphalt and concrete.
TRACTION-LIMITED GRADE
Steepest negotiable grade where traction is the
limiting factor.
TRACTIVE EFFORT
1) The maximum force developed by vehicle
powertrain at contact between driven wheels and road surface with 100%
traction. 2)The amount of power
required to move a vehicle.
TRACTIVE FORCE
The tractive force is that part of the friction
force on the tires which is directed along the vehicle centerline.
TRACTOR
Truck portion of combination or train.
TRACTOR PROTECTION VALVE
Controls flow of compressed air from tractor to
trailer when closed, stops flow of air
to trailer. When this happens, the
trailer brakes will apply. Used to make
sure that air is always available for
tractor brakes. Must be in
"Normal" position when tractor is hooked up to trailer and in
"Emergency" position to unhook trailer.
TRAFFIC
Pedestrians, ridden or herded animals, vehicles,
street cars, and other conveyances either singly or together while using any
highway for purposes of travel.
TRAFFIC ACCIDENT
An accident involving travel or transportation on a
traffficway.
TRAFFIC CONTROL SYSTEM
A block signal system under which train movements
are authorized by block signals, whose indications supersede the superiority of
trains from both opposing and following movements on the same track.
TRAFFIC UNIT
An element of traffic; a person using a trafficway
for travel or transportation; vehicle; pedal cycle, pedestrian, etc.
TRAFFICWAY
The entire width between property lines, or other
boundary lines, of every way or place of which any part is open to the public
for purposes of vehicular travel as a matter of right or custom. All highways are trafficways include also
some areas on private property such as shopping centers.
TRAIL
The horizontal distance from the point where the
steer axis intersects the roadway to the center of the tire contact patch.
TRAILER
Every vehicle with or without motive power, other
than a pole trailer, designed for carrying persons or property and for being
drawn by a motor vehicle and so constructed that no part of its weight rest
upon the towing vehicle.
TRAILER BRAKE
A hand-operated remote control that applies trailer
brakes only. Located on the steering
column or dash. Must never be used for
parking. Also called hand valve,
trolley brake, trolley valve handle, trailer hand brake, and independent
trailer brake.
TRAILER HAND BRAKE
See trailer brake.
TRAILER, FULL
Truck trailer constructed so that all its own
weight and that of its load rests upon its own wheels.
TRAILING MOVEMENT
The movement of a train over the points of a switch
which face in the direction in which the train is moving.
TRAILING POINT SWITCH
A switch, the points of which face away from
approaching traffic.
TRAIN
An engine or more than one engine coupled, with or
without cars, displaying a marker.
TRAJECTORY
Trajectory is defined as the curve which a body
follows as it moves through space. The
path is curved because the horizontal velocity is constant and the vertical
velocity due to gravity is changing.
The path through space derived from the vector summation of these two
velocities is curved.
TRAMP
The form of wheel hop in which a pair of wheels hop
in opposite phase.
TRANSFER CASE
Split power gear box transmitting drive to front
and rear axles.
TRANSFER DIE
A multi-operation die in which the panel progresses
from stage to stage by means of a transfer device.
TRANSFER PUMP
A pump used to move fuel from fuel tank to
injectors or carburetor.
TRANSIENT STATE
Transient state exits when the motion responses, the
external forces relative to the vehicle, or the control positions are changing
with time.
TRANSIENT VIBRATION
Transient vibration exists in a system when one or
more component oscillations are discontinuous.
TRANSIENT-HIGH ENERGY
A voltage spike on the power supply line of very
high voltage and long time duration (I.e. load dump which is losing a battery
connection while changing the battery).
TRANSIENT-LOW ENERGY
A voltage spike on the power supply line of very
high voltage and short time duration (I.e. the inductive load caused by the
field collapsing in a solenoid.)
TRANSLATIONAL MOTION
Motion of a rigid body in such a way that any line
which is imagined rigidly attached to the body remains parallel to its original
direction.
TRANSMISSIBILITY
Transmissibility in forced vibration is the ratio
of the transmitted force to the applied force.
TRANSMISSION (Auxiliary)
Additional gearbox increasing the gear ratio
combinations when used with main transmission or multi-speed axles.
TRANSMISSION (Main)
Selective gear box providing various combinations
of gear ratios.
TREAD
Tread is that portion of a tire that comes into
contact with the road. The peripheral portion of the tire, the exterior of
which is designed to contact the road surface.
TREAD ARC WIDTH
The distance measured along the tread contour of an
unloaded tire between one edge of the tread and the other. For tires with rounded tread edges, the
point of measurement is that point in space which is at the intersection of the
tread radius extended until it meets the prolongation of the upper side wall
contour.
TREAD CONTACT LENGTH
The perpendicular distance between the tangent to
edges of the leading and following points of road contact and parallel to the
wheel plane.
TREAD CONTACT WIDTH
The distance between the extreme edges of road
contact at a specified load and pressure measured parallel to the Y' axis at
zero slip angle and zero inclination angle.
TREAD CONTOUR
The cross sectional shape of tread surface of an
inflated unloaded tire neglecting the tread pattern depressions.
TREAD CORD WIDTH
The distance measured parallel to the spin axis of
an unloaded tire between one edge of the tread and the other. For tires with rounded tread edges, the
point of measurement is that point in space which is at the intersection of the
tread radius extended until it meets the prolongation of the upper side wall
contour.
TREAD DEPTH
The distance between the base of a tire tread
groove and a line tangent to the surface of the two adjacent read ribs or rows.
TREAD PATTERN
The molded configuration on the face of the
tread. It is generally composed of
ribs, rows, grooves, bars, lugs, and the like.
TREAD PITCH
Tread pitch is the length between corresponding
points along a tire tread.
TREAD RADIUM
The radius or combination of radii describing the
tread contour.
TREAD RIB
Tread rib is a tread section running
circumferentially around a tire.
TREAD SEPARATION (OF A TIRE)
Tread separation is the pulling away of the tread
from the tire carcass.
TREAD WEAR GRADE
The tread wear grade is a comparative rating based
on the wear ratio of a tire when tested under controlled conditions on a
specified government test course.
TREADLE VALVE
A foot-operated air service brake actuation valve.
TRIANGULATION
A method of locating a spot in an area by
measurements from two or more reference points, the locations of which are
identified for future reference.
TRI-AXLE
An assembly of three rear axles, any or all of
which may be powered.
TRI-DRIVE
Vehicle having three rear axles driving.
TRIKE
A three wheeled motorcycle which has a single front
wheel operating similarly to the front
wheel of a motorcycle and two rear wheels similar to those of an
automobile.
TRIM - THE STEADY STATE
(that is, equilibrium) condition of the vehicle
with constant input which is used as the reference point for analysis of
dynamic vehicle stability and control characteristics.
TRIM BUCK
A full-sized model of an interior to show the
design of a specific model.
Trip
An accumulation of data from extraction to extraction. ( Detroit )
Trip Calendar Time
Total Time between extractions including Engine Off Time. ( Detroit )
Trip Distance
The total miles traveled during a Trip. ( Detroit )
Trip Fuel
The total fuel used during a Trip. ( Detroit )
TRIP RISK
The danger to a traffic unit in undertaking a particular trip; the combined effect of road, vehicle, driver, weather, traffic, and schedules on the possibility of maintaining adequate driving strategy and evasive tactics.
Trip Status
A category in the Extraction Log which reports inconsistencies in Trip data. ( Detroit )
Trip Time
Time while engine was running during a Trip. ( Detroit )
TRIPLE LOAD
A shipment requiring the use of two carrying cars
with an idler car between them.
TRIPLE TREE
The steering
head assembly which connects the top of the fork to the frame and
handlebar.
TRIPLES
A combination consisting of a tractor, a
semi-trailer and two full trailers, coupled together. Known as triple headers or triple bottoms.
TROLLEY BRAKE
See trailer brake.
TROLLEY-VALVE HANDLE
Operates the trailer's brakes. See trailer brake.
TRPO
Truck and Recreation Products Office
TRUCK
1) Every motor vehicle designed, used, or
maintained primarily for the transportation of property. 2) A general term for the complete four
wheel freight car assembly which supports the car body at each end. It is attached to the body by a pair of
center plates which function as a pivot.
See center plate.
TRUCK TRACTOR
Every motor vehicle designed and used primarily for
drawing other vehicles and not so constructed as to carry a load other than
part of the weight of the vehicle and load so drawn.
TRUNNION
Journals allowing pivoting or turning such as
tandem axle spring or walking beam assembly.
TSA
(Temporary Substitution Approval) document
generated by Chrysler Plant or Corporate Product Engineering that allows a
product with a deviation in a characteristic to be received and used in an
assembly plant for a specific length of time.
TSCA
Toxic Substance Control Act
TTL
Transistor, Transistor Logic, a digital logic
system where the gates consist of mostly transistors.
TUBELESS TIRE
A tubeless tire is a pneumatic tire in which the
casing is sealed directly to the wheel rim, precluding the necessity for an
inner tube.
TULIP PANEL
Exterior body panel located between the backlight
opening and the deck lid opening.
TUMBLEHOME
Angle of the "B" pillar and side glass
from the perpendicular at the beltline, as seen from front or rear.
TUNNEL
The hump in the floor pan that provides clearance
for the driveshaft.
TUNNEL VISION
Tunnel vision is an eye condition in which objects
alerts the aide of the road, or objects approaching the road from the side, are
less likely to be seen, especially if the objects are dark and reflect a minimum
of light.
TURBINE ENGINE
An engine in which the working medium is a gaseous
fluid throughout the cycle with the principal mechanical parts driven by
turbines.
TURBOCHARGER
A type of blower, powered by engine exhaust gases,
that forces air into the intake manifold at higher than atmospheric pressure to
increase engine power and performance.
See blower.
TURBULENCE
Swirling charge of fuel and air in combustion
chamber.
TURN AROUND
A type of trip or "run" in which the
driver returns to the origin point immediately after his vehicle is unloaded
and reloaded.
TURNING CIRCLE
Twice the turning radium.
TURNING RADIUS
Radius of minimum turning circle.
TURNPIKE
Expressway or freeway.
TURNUNDER
Opposite of tumblehome. The inward and downward
sweep of sheet metal from the widest point on a car down to the rocker panel.
TWEAK BAR
An after market device mounted on the fork tubes
for stability in addition to that provided by the fender brace.
TWILIGHT
Three phases of twilight separate daylight from
full darkness, based on functional changes in visual capability. Ambient illumination falls continuously
during the three phases, which are referred to as (1) Civil Twilight, (2)
Nautical Twilight, (3) Astronomical Twilight. Each phase corresponds to a solar transit of six degrees below
the horizon and each phase last about 30 minutes in the middle latitudes of
North America. (a) Civil Twilight occurs after sunset and
before sunrise, when the upper limb of the sun is tangent with the horizon, and
the moment when the center of the sun is 6° below the horizon. (b) Nautical Twilight
occurs when the sun is between six and twelve degrees below the horizon. During this phase there is ample light to
visual the horizon for navigation at sea, but insufficient light for many other
outdoor activities. (c) Astronomical Twilight occurs when the sun
is between twelve and eighteen degrees below the horizon. This phase approaches the darkness of full
night when illumination from the sun is lower than that from the stars.
TWIN SCREW
Truck with
tandem drive axles.
TWO PIECE RESTRAINT
A lap belt.
TWO PIECE RIM
A two piece rim is a type of wheel used on
trucks. The wheel is designed in two
pieces, the pieces being called the rim base and the side ring.
TWO STROKE CYCLE
The cycle of an engine which accomplishes the
intake, compression, power and exhaust phases in to strokes of the piston. An engine with such a cycle is also called
two cycle or two stroke engine.
TWO-SPEED AXLE
A drive axle capable of being shifted through two
gear ranges in order to double the number of gears available from the
transmission.
References
Detroit Diesel
Caterpillar User's Manual