DICTIONARY OF AUTOMOTIVE TERMS - "To"

Toe:

The brake shoe end where the hydraulic or servo force is applied.
Also See:
bead toe
brake shoe toe
heel and toe wear
heel and toe
toe-in
toe-out
toe-out on turns
toe control link
tooth toe
toe steer
tooth toe.

Toeboard:

The front vertical panel that provides support for the pedals and for the front passenger's feet, usually inclined towards the front and spot-welded to the floorboard at its bottom end and to the bulkhead at its upper end

Toe clip pedals:

Older style method of securely attaching your feet to the pedals through the use of clips and straps.

Toe control link:

A lateral link in a multilink suspension designed to control a wheel's direction as the suspension moves up and down.

Toe dolly:

A flat slab of metal thinned down at one end and with a curved surface; useful for getting into awkward and narrow corners

Toe in:

See toe-in.

Toe-in:

An adjustment of the front wheels where the distance from the center of the left wheel to the center of the right wheel is less at the front of the wheels than at the back of the wheels. A slight amount of toe-in is usually specified to keep the front wheels running parallel on the road by offsetting other forces that tend to spread the wheels apart. The major force is the backward thrust of the road against the tire tread while the vehicle is moving forward. Other factors include play in the tie-rod assembly and allowance for angular changes caused by wheel bounce or variations in road conditions. Toe-in is measured in fractions of an inch or millimeters

Toe-in angle:

The angle formed by each front wheel plane and the longitudinal axis of the car, usually expressed as the difference in distance between right and left wheel rims at front and rear, measured at hub level

Toe of weld:

Junction of the face of the weld and the base metal.

Toe out:

See toe-out.

Toe-out:

An adjustment of the wheels where the front of the wheels is further apart than the back. Generally toe-out is not desirable. Toe-out is measured in fractions of an inch or millimeters. See toe-in.

Toe out on turns:

See toe-out on turns.

Toe-out on turns:

When the vehicle negotiates a curve, the inner wheel turns more sharply and while the wheels remain in this position, a condition of toe-out exists.

Toe steer:

The changes in the direction of a wheel that occur without driver steering input. Toe steer can be caused by ride steer or by deflections in suspension components caused by the stresses of cornering, accelerating, and/or braking on smooth and bumpy roads.

Toe strap:

A leather belt that attaches to a pedal cage and toe clip to secure the foot to the pedal.

Toe wear:

See heel and toe wear

TOFC:

Acronym for "Trailer On Flatcar" -- a method for moving cargo which involves transporting semitrailers on railroad flat cars. See Piggyback

Toggle switch:

A switch that is actuated by flipping a small lever either up and down or from side to side.

Toilet:

See chemical toilet

Tolerance:

1. The amount of variation permitted from an exact size or measurement. The actual amount from the smallest acceptable dimension to the largest acceptable dimension. The difference between the permissible maximum size and the permissible minimum size of a measured quantity.
2. A permissible variation, usually stated as limits of a specification.

Also See:
lead tolerance

Toll:

Money charged for the use of a road or bridge -- especially for entering controlled highways and government parks

Toll road:

A road (usually a highway) where access requires the payment of a toll or fee. The opposite is a freeway

Toll sticker:

A label or sticker displayed on the windshield indicating pre-payment of a toll

TomasoPantera:

A model of automobile manufactured in Italy
Click image for books on Pantera

Tommy bar:

1. A rod that fits in a box spanner.
2. A short bar used as a lever to provide torque for tightening a box or socket spanner. Also called a crossbar

Ton:

See:
gross ton
gross registered tons
long ton
short ton

Tone:

See:
mass tone
tint tone

Tone ring:

The gear-like ring that spins its teeth trough the speed sensor's magnetic field, causing generation of voltage by the sensor.

Tone wheel:

See tone ring.

Tongs:

See lazy tongs

Tongue weight:

The amount of trailer weight supported by the hitch. Too much, and the rear of the tow vehicle will be overloaded; too little, and the trailer will wander and weave as it's towed. Tongue weight should be between 10 and 15 percent of the total trailer weight.

Ton mile per hour:

(TMPH) A system devised to ascertain the working capacity of earthmover tires; it is a supplement to the normal load and inflation tables.

Tonnage:

A measure of the internal volume of spaces within a vessel in which 100 cu.ft. is 1 ton.
Also See:
international tonnage certificate
net tonnage

Tonnage certificate:

See international tonnage certificate

Tonnage deadweight:

See deadweight

Tonnage gross:

Gross tonnage includes a ship's internal volume, excluding such spaces as the peak, double bottom, deep tanks used only for water ballast, bridge, forecastle, open-ended poop, certain light and air spaces, skylights, anchor and steering gear spaces, toilets, the wheelhouse, and certain passenger spaces

Tonnage net:

Net tonnage is the gross tonnage less certain additional spaces such as crew and officer spaces, chart room, and a percentage of the propelling machinery spaces; also see deadweight, displacement, light and displacement, loaded

Tonnage openings:

Nonwatertight openings in the shelter deck and in the 'tween deck bulkheads immediately below in order to exclude spaces from tonnage measurement and thus obtain reduced gross and net tonnage. The openings could be closed by nonwatertight wood shifting boards or metal covers meeting the tonnage and load line regulations

Tonneau:

See tonneau cover.

Tonneau cover:

A cover of leather or other soft pliable material used for protecting the interior of a convertible when the soft top is down. The cover snaps to the dash sides, and rear of the vehicle and often has a zipper allowing the driver to operate the vehicle while the passenger side of the vehicle remains covered.

Ton of refrigeration:

Refrigerating effect equal to the melting of 1 ton of ice in 24-hours. This may be expressed as follows: 288,000 BtuI24 hr., 12,000 Btu/1 hr., 200 Btu/min.

Ton refrigeration unit:

Unit which removes same amount of heat in 24-hours as melting of 1 ton of ice.

Tool:

1. As a noun, it is any device which assists in the installation or removal of a component.
2. To work material by turning, milling, grinding, polishing, drilling, punching, boring, shaping, shearing, pressing, or planing.
3. As a colloquial verb, it is the action of motion as in We were tooling down the highway when we saw you.

Also See:
adjusting tool
air tool
automotive tool
brake adjusting tool
clutch aligning tool
crimping tool
drive tool
electrode adjusting tool
flanging tool
flaring tool
heated tool welding
joint splitting tool
magnetic pick-up tool
pick-up tool
pinstriping tool
pushrod measuring tool
retainer spring tool
silencer-tailpipe tool
striping tool
taper-breaking tool
trim panel release tool
valve grinding tool

Tool bit:

The hardened steel or carbide blade that cuts away metal during machining.

Tool cart:

A tiered table (usually on wheels) designed to hold the pertinent tools for performing repairs on a vehicle.

Tooling:

1. Set of required standard or special tools needed to produce a particular part. It includes jigs, fixtures, gauges, and cutting tools; but excludes machined tools. Also see tool.
2. A colloquial term for driving, as in "I was tooling down the road when another car hit me."

Toolkit:

See ignition toolkit

Tool welding:

See heated tool welding

Tooth:

See:
gear tooth
hunting tooth
radiator hose shark tooth pliers

Toothed belt:

A positive-action reinforced rubber or plastic belt in which parallel teeth engage with grooves in a driving and a driven wheel; commonly used for the valve timing gear as an alternative to a roller chain

Toothed signal rotor:

The component of an ABS system that rotates with the hub, driveaxle, axle, or ring gear, used along with the wheel speed sensors for generating impulses to the rear by the ABS electronic control unit (ECU). The ECU counts these impulses and determines if a wheel is decelerating too rapidly or not

Tooth heel:

The wider outside end of the tooth in the differentialring gear.

Tooth pliers:

See radiator hose shark tooth pliers

Tooth toe:

The narrower inside end of the tooth in the differentialring gear.

Top:

1. A car roof, especially that of a convertible.
2. The highest gear of a transmission.

Also See:
canvas top
convertible top
electric top
fabric top
folding top
hydraulic top
piston top
soft top
sunroof top
targa top

Top cap:

When retreading a tire, new tread rubber is added to the buffed casing covering only the crown area. Also see full cap.

Top carriers:

A cage of chrome bars which attaches to the gutter rails on the roof of a car or van. It is used to secure loads on a vehicle roof, such as bulky containers, skis, or bicycles

Top case:

A top case sits behind the passenger seat of a motorcycle and may be large enough to hold two full-face helmets. Like the tank bag, a top case is meant to hold lightweight items. Overloading a top case puts more weight on the rear of the motorcycle, thus lightening the front wheel. Traction and steering suffer when the top case is overloaded.

Top chop:

A modification of the roof of custom cars. The roof pillars are cut off and shortened: when the roof is welded back on, the roof line is far lower than before and the screen and side window height may have been reduced to a minimum. Due to problems of rigidity and finding suitable glass panes, this modification is extremely difficult

Top coat:

A final paint coat

Top coat drier:

An oven for drying or stoving the final paint coat

Top coat oven:

An oven for drying or stoving the final paint coat

Top dead center:

(TDC) Highest point of piston and connecting-rod travel in a cylinder; the ends of the compressionexhaust strokes in a four-cycle engine.
Also See:
after top dead center
before top dead center

Top electrode:

The ground electrode protruding above the center electrode of a spark plug, either full coverage type or set back slightly from the far edge of the center electrode

Top end:

1. The upper range of engine revolutions.
2. The upper part of the engine (pistons, cylinder, valve gear, induction system) from the base gasket to the valve cover

Top end gasket kit:

The gaskets that apply to everything from the base gasket up (e.g., base gasket, head gasket, manifold gaskets, carburetor mounting gaskets) as well as all the O-rings and replaceable spacers. Contrasts with the bottom end gasket kit.

Top end speed:

The maximum speed which a vehicle can attain. This may differ from the maximum speed allowed by the law and from the recommended maximum speed of a vehicle. In some vehicles, governors are installed to limit the speed so that top end speed is not attained. Others may use warning lights or flashing speedometer readings (i.e., on digital displays) or even warning sounds.
Also See:
bury the needle
red line.

Top feed gun:

See gravity-feed spray gun

Top gear:

The highest available gear

Top hat section:

A structural sheet metal member of U-section, but incorporating flanges for welding or assembling the section to a flat mating panel

Top land:

See head land

Top off:

Fill a partially filled container to full capacity.

Top-of-the-line model:

The most powerful and expensive model in a particular manufacturer's lineup of vehicles

Top-of-the-range model:

See top-of-the-line model. The most powerful and expensive model in a particular manufacturer's lineup of vehicles

Toppers:

See whitewall toppers

Top ring groove insert:

A piston ring that has a nickel-iron or comparable metal insert cast into the piston heads. The top ring groove is cut into this metal. As the top ring grooves in aluminum pistons pound out of shape, this insert groove will prolong the useful life of the piston and ring.

Top speed:

The maximum speed of a vehicle

Top tints:

The tinted stripe at the upper edge of the windshield

Top tube:

On a bicycle the horizontal tube that connects the seat tube with the head tube.

Top up:

To raise the level of a liquid in a container to the required level

Top up the battery:

Determine if the electrolyte is at the correct level and add distilled water to bring it up if necessary

Torch:

1. The mechanism which the operator holds during gas welding and cutting, at the end of which the gases are burned to perform the various gas welding and cutting operations.
2. A British term for a flashlight.

Also See:
blow torch
cutting torch

Toronado:

A vehicle brand of which the 1966-67 Toronado models are milestone cars. Sometimes you will see this car incorrectly spelled "Tornado" in classified ads.
Click image for books on Toronado

Torpedo:

An open sports vehicle generally with an unbroken design line from the hood to the back of the car.

Torpedo body:

An early type of touring car with a streamlined torpedo-like body

Torque:

1. Turning or twisting force such as the force imparted on the drive line by the engine. Usually measured in lb-ft. It differs from work or power in that torque does not necessarily produce motion. Basically, the magnitude of a torque acting on a body is the product of the magnitude of a force and its force arm (perpendicular distance from the axis of rotation of the body to the line of action of the force). This product is called the moment of the torque about the axis or the torque.
2. To tighten a nut or bolt with a torque wrench.
3. The turning or twisting force applied at the end of a rotating shaft. It is force applied multiplied by the torque arm. In the traditional system the units are pound-force-foot (or foot-poundforce). The units in the SI and metric systems are newton-meter or dyne-centimeter respectively.

Also See:
bottom end torque
dial torque wrench
hydrodynamic torque converter
interchangeable head torque wrench
lock-up torque converter
lockup torque converter
midrange torque
self-aligning torque.

Torque arm:

1. A T-shaped extrusion of the rear axle casing to take up forward thrust of the driven axle
2. Defined as the distance from the center-point of rotation to the point at which the force is applied. If torque is being applied using a wrench, the length of the torque arm is the same as the length of the wrench.

Torque converter:

A unit in an automatic transmission
quite similar to the fluid coupling that transfers engine torque to the transmissioninput shaft. It also cushions the flow of power. Unlike the fluid coupling the torque converter can multiply engine torque. This is accomplished by installing one or more stators between the torus members. In the torque converter the driving torus is referred to as the "pump" and the driven torus as the "turbine." The engine drives the impeller which in turn impels fluid against the vanes of a turbine connected through transmission gears to the driveshaft of the automobile. The stator redirects oil flow from the turbine to boost impeller action and multiply engine torque.
Also See:
hydrodynamic torque converter
lock-up torque converter
lockup torque converter

Torque converter drive plate:

See drive plate

Torque converter housing:

A bell housing

Torque converter lock-up clutch:

An automatically engaged clutch in a lock-up torque converter which prevents slipping losses

Torque curve:

A graph which shows the engine torque as a function of engine speed

Torque, full load:

Maximum torque delivered without overheating.

Torque limiter:

A tool used in conjunction with a plug wrench which allows the controlled tightening of spark plugs by releasing automatically once a preset torque setting is reached

Torque multiplication:

Increasing engine torque in the automatic transmission through the use of a torque converter.

Torque plate:

See caliper mounting bracket.

Torque ratio:

See stall torque ratio

Torque rods:

See stabilizer.

Torque screwdriver:

A screwdriver with a device that measures the amount of torque being applied

Torque sensitive limited slip differential:

A differential where the mechanism reacts to differences in torque when one wheel on an axle starts to slip, and limits the differential action to help maintain traction.

Torque sequence:

The order in which a series of bolts or nuts should be tightened.

Torque split:

Distributing torque between wheels on the same axle or between front and rear axles in a 4WD vehicle

Torque stall:

The amount of force required to start a shaft turning. Once in motion, the amount of torque to keep the shaft turning is much less.

Torque, starting:

Amount of torque available, when at 0 speed, to Stan and accelerate the load.

Torque steer:

A tendency for a car to turn in a particular direction when power is applied. Torque steer is common in front-drive cars because reaction forces created in the half-shafts can generate uneven steering forces in the front tires.

Torque tube:

A hollow forward extrusion of the rear axle casing incorporated in early live rear axle designs, both enclosing the drive shaft and providing a forward location of the driven axle, pivoting about a spherical joint either at the rear end of the gearbox or at the chassis frame

Torque tube axle:

A live rear axle layout with a divided drive shaft and a T-shaped axle housing, the hollow forward extrusion of which carries the rear half of the divided drive shaft

Torque tube drive:

The method of connecting the transmissionoutput shaft to the differentialpinion shaft by using an enclosed driveshaft. The driveshaft is enclosed in a torque tube that is bolted to the rear axle housing on one end and is pivoted through a ball joint to the rear of the transmission on the other. The driving force of the rear wheels is transferred to the frame through the torque tube. This method was used on older cars in an attempt to get rid of the twisting forces of engine torque on the suspensiondriveshaft.

Torque wrench:

A wrench with a dial in the handle or a gauge with a needle for measuring the amount of pressure applied to a nut or bolt. It is used for threaded fasteners with a critical tightening torque, such as cylinder head bolts, alloy wheel lugs, suspension links, etc.
Also See:
click-type torque wrench
dial torque wrench
interchangeable head torque wrench

Torquey:

An engine which develops high torque (i.e., it pulls well) at low speeds, relative to its power

Torquing:

See brake torquing

Torsen differential:

A torque-sensing differential system incorporating a worm and roller mechanism

Torsen four-wheel drive:

Based on the principle that a worm gear can drive a roller but not vice versa, the Torsen differential balances different wheel speeds due to different travel distances, whereas speed differences due to differing adherence situations are not balanced. A permanently engaged four-wheel drive incorporating a torsen differential

Torsion:

The strain on a part or component produced by torque

Torsional rigidity:

The resistance against torsional loads, specified in newton-meter per angular degree of body twisting.

Torsional stiffness:

The resistance against torsional loads, specified in newton-meter (or lbs-ft) per angular degree of body twisting

Torsional vibration:

A twisting and untwisting action developed in a shaft. It is caused either by intermittent applications of power or load.

Torsional vibration damper:

1. Any device that reduces torsional vibrations.
2. The small flywheel on the front end of a crankshaft

Torsion bar:

A long spring steel rod or flat bar attached in such a way that one end is anchored while the other is free to twist. One end is fastened to the frame at one end and to a suspension part at the other. If an arm is attached at right angles, to the free end, any movement of the arm will cause the rod or bar to twist the bar's resistance to twisting provides a spring action. The torsion bar replaces both coil spring and leaf springs in some suspension systems. The main advantage of the torsion bar over the coil spring in the front suspension is the ease of adjusting front suspension height. Some are mounted longitudinally (i.e., front of car to back of car) or transversally (i.e., from the left side to right side of the car).

Torsion bar suspension:

A suspension system that makes use of torsion bars in place of the leaf or coil spring.

Torsion damper:

See torsional vibration damper

Torsion spring:

See torsion bar.

Torus:

The inner surface of a hollow doughnut-shaped structure, especially found in automatic transmissions. See fluid coupling.

TORX:

A special star-shaped screw recess or screw head top with six rounded corners to insert the tool. The TORX configuration on tools allows a very tight fit on the fastener and the application of high torque. The rounded corners also reduce wear of both the fastener and the tool

Total energy management:

Conservation concept where a building is looked at in terms of its total energy usage, rather than analyzing the requirements of separate systems.

Total heat:

Sum of both the sensible and latent heat.

Total hydrocarbons:

(THC) A measurement of all the hydrocarbons emitted by the exhaust system

Total indicator reading:

(TIR) In disc brakes, this refers to a rotor runout reading of the entire swing of the dial indicator's needle, both above and below zero.

Totalled:

A car accident in which a vehicle has sustained severe damage so that the cost to repair it is more than what the vehicle is worth. In this case, it is written off

Total loss:

Ignition or lubrication system in which electricity or oil is used without being generated or recirculated. The ignition system uses power from a battery eventually running it flat. The lubrication system uses oil without returning it to a tank. Both systems were common on early motorcycles. Two-stroke engines use a total loss lubrication system. Scooters designed for the elderly or disabled use a total loss battery system because there is no alternator or generator to charge the battery as it is being driven

Total-loss lubrication:

The components of the conventional two-stroke engine with crankcase scavenging are lubricated by the oil added to the fuel; since the oil is burnt along with the fuel, fresh oil is constantly fed to the lubrication points inside the engine

Totally enclosed:

An electric motor housing that has no openings (but is not airtight). Used in locations where dirt, oil, etc. is present. It may be fan-cooled or convection cooled.

Totally enclosed fan-cooled enclosure:

(TEFC) An electric motor housing that includes an integral fan to blow cooling air over the motor. Also see explosion-proof enclosure

Totally enclosed non-ventilated enclosure:

(TENV) An electric motor housing that is not equipped with a fan for external cooling, but depends on convection air for cooling

Total Out-Of-Pocket Cost:

This is the total of all monthly payments, any lease fees and deposits, and any capital cost reduction (except tax, license, and registration) from lease inception to closure.

Total quality management:

(TQM) A management technique to improve the quality of goods and services, reduce operating costs and increase customer satisfaction.

Total static head:

Static head from the surface of the supply source to the free discharge surface.

Touch-dry:

The condition after respraying a body when the paint coat has dried to an extent that foreign substances will not stick to the surfaces and light finger pressure will not leave any marks; the coat has not yet hardened completely, however, i.e., it cannot yet be sanded or polished

Touch up:

To repair minimal blemishes in the paintwork, e.g., those caused by stone chippings or scratches

Toughened glass:

See laminated windshield.

Toughened windshield:

A windshield made of toughened glass which, on impact, will not shatter like ordinary glass but fractures into small pieces and crazes over; laminated glass is now the preferred material

Tour:

See farewell tour

Tourer:

British term for touring car
Also See:
loaded tourer
sports tourer
AC Buckland Open Tourer.

Touring:

See:
Grand Touring Prototype
Grand Touring

Touring bike:

1. A motorcycle that comes from the manufacturer with saddlebags and a trunk.
2. A bicycle that has been equipped with saddlebags (often over the front wheels as well as the rear).

Touring car:

A vehicle with a body longer than the phaeton style, but very similar to it. It permits the use of auxiliary seats in the rear passenger compartment. It was an open car with seats for four or more passengers. Early models had no side weather protection but later were fitted with detachable side screens and curtains. Made until about 1930.

Touring-injection:

See grand Touring-injection

Touring Prototype:

See camel Grand Touring Prototype

Touring triple:

A triple chainring crankset designed to provide the wide range of gears needed for loaded bicycle touring.

Tourist:

A cyclist who takes short or long excursions by bicycle often carrying several panniers containing clothing and camping equipment.

Touristes-routiers:

An older and slower category randonneur used in the 1901, 1911, and 1921 Paris-Brest-Paris events. In 1931 the race organizers turned this segment over to touring clubs.

Tow:

1. To pull a trailer behind a vehicle by means of a towing hitch.
2. To pull a disabled vehicle behind another vehicle by means of a rope, cable or rigid bar

Towable:

1. A vehicle after an accident that is able to be towed.
2. An old vehicle which may be used for parts or to be scrapped that is still able to be towed

Tow away:

To remove unauthorized (e.g., illegally parked) vehicles, thus incurring a hefty fine for the owners

Tow away zone:

An area where unauthorized parking is not permitted. Unauthorized vehicles will be towed away

Towball:

A British term for a hitch ball

Towbar:

1. A crossbar of a towing bracket on which the hitch ball is mounted.
2. A rigid bar used for towing disabled vehicles short distances.
3. A drawbar

Tower:

See:
coil tower
distributor tower
humidifying tower
macpherson strut tower
outer tower
shock absorber tower
terminal tower

Tower jack:

A tower with a solid foot and an arm at right angles which fits into a slot in the side of a car and is wound up the tower to raise the vehicle

Towing ball:

A British term for a hitch ball

Towing bracket:

A structure attached to the rear of a car to enable a trailer to be towed. It consists of one or two brackets, a towbar and hitch ball

Towing eye:

A steel ring fitted to the chassis of a car to which a tow rope can be attached

Towing hitch:

An inverted cup on the drawbar of a trailer which fits over a hitch ball

Towing jaws:

A coupling attachment on the rear of a truck cab into which the drawbar eye of a trailer fits to lock with a coupling bolt

Towing lug:

A steel ring fitted to the chassis of a car to which a tow rope can be attached

Towing package:

See trailer towing package

Town car:

The same as the Imperial sedan without the rear quarter windows or a roof over the front compartment.

Tow rating:

The amount of weight in pounds of an external trailer that a vehicle can pull.

Towrope:

A rope, or textile-covered or plastic-covered cable, usually no longer than 5 meters, used for towing another vehicle

Toxicity:

Refers to the physiological effect of absorbing a poisonous substance into the system, either through the skin, through mucous membranes or into respiratory system. When describing their toxic effect, solvents are usually classified as having high, medium, or low toxicity, depending upon whether a solvent vapor concentration of less than 100, 100 to 400 or over 500 parts per million respectively is the maximum amount permissible in the air for safe or healthful working conditions.

Toyota:

The largest car manufacturer in Japan and the third largest in the world (after GM and Ford)
Click image for books on Toyota

Sign My Guestbook View My Guestbook