Explanatory Dictionary — abbreviations (BMW X3 E83)

ABS (Anti-lock braking system) - anti-lock braking system. An electronically controlled feedback system that prevents wheel locking during braking and maintains vehicle control and directional stability.

ATF (Automatic Transmission Fluid) - automatic transmission working fluid.

DOHC (Double-overhead camshaft) - a type of engine valve timing mechanism that uses two camshafts located in the cylinder head, one of which controls the intake valves and the other the exhaust valves.

IC is an abbreviation used to denote integrated circuit.

LCD (Liquid crystal display) - an abbreviation used to denote liquid crystal display.

LED (Light-emitting diode) - an abbreviation used to denote a light-emitting diode (see "LED").

SOHC (Solo Overhead camshaft) - a type of valve timing mechanism that uses a single camshaft located in the cylinder head.

TCS (Traction Control System) - a traction control system or anti-skid system designed to maintain the amount of slippage of the vehicle's drive wheels within established limits by monitoring the amount of slippage and correspondingly reducing engine torque.

VIN (Vehicle Identification Number) - vehicle identification number. Used to identify the engine cylinder block and car body (motorcycle frames).

A

Car tires are one of the most important elements, which is an elastic shell located on the rim of the wheel. The tire is designed to absorb minor vibrations caused by imperfect road surfaces, to realize and perceive the forces arising in the contact patch and to ensure a high coefficient of adhesion. By type of construction, depending on the location of the cord (frame element), there are diagonal and radial tires. In radial tires, the cord threads are arranged along the shortest distance between the beads. In diagonal ones, they are at some angle and intersect each other. Currently, only radial tires are installed on passenger cars. Bias tyres continue to be used on motorcycles, mopeds, earthmoving and agricultural machinery.



Aquaplaning is a condition in which a film of water separates the tire from the road surface. It occurs when the pressure of a wedge of water, not displaced from the contact patch of the tire with the road, lifts the tire off the road. The tendency to aquaplaning depends on the thickness of the water film on the road surface, the speed of the vehicle, the shape of the tread pattern, its wear and the pressure exerted by the tire on the road.

Cushioning is the process of damping shock loads and vibrations.

Ampere (A) is a unit of measurement of current strength.

Ampere-hour (Ah) is a unit of measurement of battery capacity.

Antifreeze is an aqueous solution of alcohols, glycols, glycerin and some inorganic salts that does not freeze at low temperatures and allows for a lower freezing point of the coolant and an increase in its anti-corrosion properties.

B

A drum brake is a type of braking mechanism whose main parts are a brake drum and brake shoes with brake linings. Drum brakes are designed as an internal shoe brake, the shoes of which are pressed against the inner surface of the brake drums rotating with the wheels by means of pistons in the wheel cylinder. Thus, the car is braked.

Infinite resistance (∞) is the resistance value that characterizes an open electrical circuit.

Runout is the magnitude of radial or axial deviation during rotation of a body (for example, a brake disc).

Side clearance is the amount of travel (maximum distance) between two elements of a mechanism, one of which is necessarily stationary.

IN

Vacuum meter - a device for measuring rarefaction (vacuum).

A shaft is a rod-shaped element of a mechanism designed to transmit torque.

Watt (W) is a unit of power.

Top dead center (TDC) is the position of the piston in the cylinder, corresponding to the maximum distance between any point of the piston and the axis of rotation of the crankshaft (conventional initial position of the crankshaft, zero degrees of crank rotation).

Wobbling - see "Shimmy".

A water pump is a mechanically driven device designed to forcefully circulate coolant in the engine cooling system.

An air intake is a structural element of a machine that serves to draw in ambient air and direct its supply to various internal systems, units, and components for various purposes: as a coolant, an oxidizer for fuel, to create a reserve of compressed air, etc. Air is drawn in by the pressure created by the flow of incoming air, or by the vacuum created, for example, by the piston's stroke in the cylinder.

Volt (V) is a unit of measurement of electric current voltage.

Fuel injection - a fuel-air mixture dosed electronically and supplied to the engine intake manifold (central or single-point injection) or directly into the cylinder (distributed injection).

All-season oil (Multigrade oil) - a motor oil that meets the requirements of more than one SAE viscosity grade (Society of Automotive Engineers) (see SAE viscosity grades), and therefore may be suitable for use over a wider temperature range than an oil with a single viscosity grade.



A bushing is a cylindrical piece of metal or other material used between two moving parts.

An electric current rectifier is a mechanical, vacuum tube, semiconductor or other device designed to convert alternating input electric current into direct output electric current

Valve opening height is the maximum distance the valve rises above the valve seat during opening.

Viscosity is a property of fluids (liquids and gases) resist the movement of one part relative to another.

G

A generator is a device designed to convert the mechanical energy of an internal combustion engine into electrical energy to recharge the battery and power the vehicle's electrical circuit.

A sealant is a polymeric substance, ranging from liquid to pasty, that has the ability to seal various joints, seams, and connections.

Hygroscopicity is the property of some substances to absorb water vapor from the air. For example, brake fluids have this property, therefore, in order to maintain the qualities necessary for the normal functioning of the braking system, it is necessary to maintain the tightness of the storage vessels, as well as the components of the braking system.

A cylinder liner is a cylindrical part made of high-carbon alloy steel, inserted into a cylinder block made of aluminum alloys.

Hypoid transmission - (short for hyperboloid), a special type of helical gear transmission, carried out by bevel gears with intersecting axes. Hypoid gear wheels can have oblique or curved teeth; the angle of intersection of the axes is usually 90°.





The main gear is a gear mechanism of a car transmission, used to transmit and change the direction of torque from the driveshaft (gearboxes) to the drive wheels, as well as to change the traction force.

D

Double helical gears (herringbone gears) - gears that are a combination of two helical gears with opposing teeth (in the shape of the letter V). The axial moments of both halves of such a wheel are mutually compensated, so there is no need to install axles and shafts in special bearings.

Detonation is a supersonic complex consisting of a shock wave and an exothermic chemical reaction behind it. Internal combustion engines with spark ignition are quickly destroyed by detonation, as they are designed for slow combustion of the combustible mixture. Rapid detonation combustion dramatically increases the pressure in the combustion chamber, which leads to rapid engine failure. In case of strong detonation - less than a minute. Fuel with a higher octane rating is better at resisting detonation.

Detonation in an engine is an isochoric (explosive) process of combustion of a fuel-air mixture without performing work, with the conversion of the combustion energy of the fuel into the temperature and pressure of the gases. The flame front spreads at the speed of an explosion, leading to strong impact loads on the parts of the cylinder-piston and crank-connecting rod groups, and thereby causing increased wear of these parts. High gas temperatures lead to burnout of the piston bottoms and burning of the valves.



A diaphragm is an elastic membrane that acts as a partition between two chambers with variable pressure.

A diaphragm spring is an elastic element in the form of a diaphragm that provides uniform clamping force around the circumference.

A diode is a semiconductor device that contains a single PN junction, allowing electric current to flow in only one direction.

A disc brake is a braking mechanism in which, unlike a drum brake, the brake pads are pressed against the brake disc.

Free length is the length of an element measured in an unloaded state.

AND

Liquid crystal display - a flat panel display based on liquid crystals, as well as a monitor based on such a display.

3

A scuff is the formation of a groove visible to the naked eye as a result of seizure, with the material being pushed both to the sides and in the direction of sliding.

Gap is the distance between two parts (for example, between the piston and the cylinder, between the bearing and the shaft).

Angle tightening is a method of tightening a threaded connection by turning a bolt or nut at a certain angle. A special angle wrench is used for tightening at an angle (see picture).



A toothed drive belt is a belt designed to transmit torque between shafts without slipping (for example, to drive the gas distribution mechanism).

AND

A needle bearing is a type of rolling bearing in which the rolling elements are small diameter rollers (needles) located between two rings (internal and external) made of high-carbon steel.

A tire wear indicator is an indicator in the form of transverse stripes that becomes visible when the tire tread reaches its wear limit, indicating the need to replace the tire with a new one.

A dial indicator is a measuring device with a pointer indicator, designed to measure the amount of play in moving elements of mechanisms.

TO

Pre-ignition is the premature spontaneous ignition of the fuel-air mixture from a hot substance, such as carbon deposits formed in the combustion chamber, or from overheated (over 700-800°C) parts - spark plugs, cylinder heads, exhaust valves, etc. Pre-ignition disrupts the normal combustion process of gasoline and is directly related to the development or occurrence of detonation. Combustion during glow ignition is similar in its physical nature to normal combustion, but it begins earlier, over a larger area, and proceeds faster. Premature ignition is a self-developing process, so the moment of spontaneous ignition occurs earlier and earlier. The pressure and temperature in the combustion chamber increase significantly, reaching their peaks even before the piston reaches TDC. This causes increased stress on the cylinder-piston assembly and crankshaft components, increasing engine noise, including a dull knocking sound that is difficult to distinguish from other engine sounds. But the main thing is that glow ignition leads to a significant increase in thermal loads on the surfaces that form the combustion chamber. Typically, the piston melts and/or burns out and the spark plug electrodes melt.

Camber - see Camber.

Combustion chamber is a volume formed by a set of engine parts in which the combustion of the combustible mixture occurs. The design of the combustion chamber is determined by the operating conditions and purpose of the mechanism.

A cardan shaft is a device for transmitting torque between units whose relative position in space is not constant: for example, from a gearbox (transfer case) to the drive axles in the case of a classic or all-wheel drive configuration. Also used in the safety steering column to connect the steering shaft and steering actuator (steering gear or steering rack).

Caster (castor or castor, from the English Caster angle) — the angle between the vertical and the projection of the wheel rotation axis onto the longitudinal plane of the vehicle. Longitudinal tilt ensures self-alignment of the steering wheels due to the vehicle speed.

A catalytic converter is an element that cleans exhaust gases from internal combustion engines by converting toxic components into more harmless compounds.

Oxygen sensor - an oxygen sensor in the exhaust manifold of the engine. Allows you to estimate the amount of free oxygen remaining in the exhaust gases.

A valve is a device installed on a pipeline or vessel and designed to open or close when certain conditions occur (increasing the pressure in the vessel, changing the direction of the flow of the medium in the pipeline). Valves have a large number of design variations. Valves can be single-seat or double-seat, the latter are usually used only as distribution and control valves. Depending on the direction of flow through the valves, valves are divided into straight-through, straight-through and angle valves. In straight-through valves, the working medium at the outlet of the housing has the same direction as at the inlet. Straight-through valves are straight-through valves with a straightened flow line. They have lower hydraulic resistance compared to straight-through ones. In angle valves, the direction of flow of the medium at the outlet is perpendicular to the direction of flow at the inlet.

Valve clearance is the gap between the valve stem and the tappet (camshaft), designed to compensate for thermal expansion during operation of an internal combustion engine.

An Allen key is a hexagonal rod that fits into the internal hexagonal slot of a bolt head.

Wheelbase is the distance between the axles of the front and rear wheels of a vehicle.

Compression is a force applied to a gaseous body, resulting in a reduction in the volume it occupies, as well as an increase in pressure and temperature. Compression occurs in compressors, as well as during the operation of an internal combustion engine and other devices.

Bevel gears - used to change the direction of torque by an angle of 90°.



Lock-nut (lock nut) - a nut used to secure an adjusting nut or other threaded elements in one position.

Taper is a deviation from the cylindrical shape of holes or shafts, characterized by a change in diameter over a certain length.

The main (bearing) journal is the mounting surface of the crankshaft or camshaft.

Main bearings are bimetallic plain bearings installed on the main bearings of the crankshaft or camshaft.

Gearbox (KB; gear change box, gear shift box (gearbox)) - obsolete terms, currently not used in technical terminology) - a mechanism used in the transmission of vehicles with internal combustion engines, designed to change the engine torque in magnitude and direction, as well as a long-term disconnection of the power unit from the propulsion system (wheels or tracks). According to the control type, a distinction is made between mechanical and automatic transmissions.

A short circuit is an electrical connection between two points of an electrical circuit with different potential values, not provided for by the design of the device and disrupting its normal operation. A short circuit can occur when the insulation of current-carrying elements is damaged or due to mechanical contact between elements operating without insulation. A short circuit is also a condition when the load resistance is less than the internal resistance of the power source.

A helical gear is a gear whose teeth are positioned at an angle to the axis of rotation, providing smoother and therefore less noisy engagement of the gear teeth. The disadvantage of helical gears is the occurrence of a mechanical moment during operation directed along the axis of rotation of the gear, which requires the use of thrust bearings, as well as increased heat generation as a result of the increase in friction surfaces of the teeth. Double helical (herringbone) gears are free from these problems (see Double helical gears).

Torque (moment of force) - a physical quantity that characterizes the rotational action of a force on a solid body.

The body is the part of the car designed to accommodate passengers and cargo. The body is attached to the car frame. There are also frameless bodies that simultaneously serve as a frame—all other components and assemblies of the car are attached to them.

L

Lambda probe (A-probe) - see "Oxygen sensor".

M

A manometer is a device designed to measure pressure.

"Ground" is a short circuit of the electrical circuit in the car to the battery through the body.

A micrometer is a highly accurate measuring instrument designed for measuring outside diameters.

A multimeter is a measuring instrument designed to measure voltage, current and resistance of an electrical circuit.

N

Bottom dead center (BDC) is the position of the piston in the cylinder that corresponds to the minimum distance between any point of the piston and the axis of rotation of the crankshaft (conventional initial position of the crankshaft, zero degrees of crank rotation).

A bore gauge is a measuring device designed to measure the internal diameter of a hole.

Newton is a unit of force.

Newton meter (Nm) is a unit of measurement of torque.

ABOUT

Overrunning clutch (freewheel clutch) — a part of a mechanical transmission that prevents the transfer of torque from the driven shaft back to the driving shaft if, for any reason, the driven shaft begins to rotate faster. The most well-known application of the overrunning clutch is in bicycle drive. When the rider stops pedaling and the bike continues to move by inertia, the overrunning clutch engages, disengaging the wheel from the pedals so they don't hit the legs. Sometimes overrunning clutches are used in cars with two-stroke engines, for which the "engine braking" mode is impossible due to design features (more precisely, the principle of lubrication), which can disable them. Another widespread application of the overrunning clutch is its use in internal combustion engine starters to prevent the starter from being destroyed by the running engine.

Ovality is the difference in hole diameters measured in mutually perpendicular directions.

Octane number is a value that characterizes the fuel's resistance to detonation.

Ohm (Ω) is a unit of measurement of resistance in an electrical circuit.

An ohmmeter is a device for measuring the resistance of an electrical circuit.

Ignition advance is the ignition of the working mixture in the engine cylinder before the piston reaches TDC.

Axial clearance (axial play) - play of the element in the axial direction.

An axis is a rod-shaped element of a mechanism that, unlike a shaft, does not transmit torque but is intended solely for positioning rotating parts.

Coolant is the working fluid of the engine cooling system, which consists of water, antifreeze, and special additives that protect the internal combustion engine cooling system from corrosion processes and the liquid itself from thermochemical destruction. Currently, mainly ethylene glycol-based coolants are used. All ethylene glycol coolants differ in quality from each other only in the set (or absence) necessary additives and the degree of dilution with water. Glycol-based coolants are not hazardous to humans. They are poisonous only when ingested.

P

Gear ratio is the ratio of the number of teeth of the driving gear to the number of teeth of the driven gear in a gear transmission, the number of teeth of the worm wheel to the number of worm entries in a worm gear, the number of teeth of the large sprocket to the number of teeth of the small sprocket in a chain transmission, and the diameter of the large pulley (or roller) to the diameter of the smaller one in a belt or friction transmission.

Alternating current is an electric current that periodically changes in magnitude and direction (usually sinusoidal). Thus, this type of current has properties that are favorable for transmitting electrical energy over a distance, since it allows for easy voltage transformation in transformers. Three-phase alternating current generators are widely used in automobiles due to their more compact size compared to direct current generators.

A flat feeler gauge is a strip of a certain thickness made of high-alloy steel, designed to measure gaps between parts.

Electrolyte density is a value that characterizes the state of the electrolyte in a battery.

Suspension is a set of parts, assemblies and mechanisms that connect the vehicle body to the supporting elements (wheels, rollers, skis, etc.). The suspension is designed to reduce dynamic loads and ensure their uniform distribution on the supporting elements during movement, and also serves to improve the traction qualities of the machine.

A bearing is a mechanical element used to reduce friction and associated wear and heat generation between two working surfaces in contact with each other. The most common bearings found in a car are ball, roller, needle, tapered and plain bearings (bimetallic liners).

Plain bearings are a support or guide for a mechanism or machine in which friction occurs when mating surfaces slide. A plain bearing is a housing with a cylindrical bore into which a liner or bushing made of antifriction material and a lubricating device are inserted. Between the shaft and the bearing sleeve bore there is a gap filled with lubricant, which allows the shaft to rotate freely.

All-wheel drive is a vehicle transmission design in which the torque generated by the engine is transmitted to all wheels. It is necessary to differentiate between the designations of all-wheel drive AWD (All Wheel Drive) and 4WD, because contrary to popular belief, these are not the same thing: AWD means permanent or automatically connected all-wheel drive, and 4WD means all-wheel drive that is connected and disconnected manually.

A semi-axle is a shaft designed to transmit torque from the main transmission to the wheels of a vehicle.

A piston pin is a rod used to connect the piston to the upper head of the connecting rod.

Firing order is the order of ignition of the fuel-air mixture in the cylinders of an internal combustion engine.

Direct current is a directed movement of electric charges that does not change in magnitude or direction.

Maximum permissible value is the value of a geometric or physical indicator of a part, upon reaching which further operation of the part is impossible or unsafe. The part must be replaced with a new one.

A fuse is a device that breaks an electrical circuit when the current is exceeded and thus prevents damage to the elements of the electrical circuit.

Drive shaft - any shaft used to transmit torque.

Suspension breakdown is a situation in which the suspension spring, as a result of hitting an obstacle, is compressed to the limit and the impact is transmitted to the rubber stops, and through them to the body elements. Often the suspension cannot withstand such overloads and collapses.

Conductance of a circuit is the reciprocal of resistance in an electrical circuit. Characterizes the closed state of the circuit.

Bleeding a hydraulic system is the process of removing air from the components of a hydraulic system (brakes, clutch, cooling, power steering, etc.) through specially designed fittings or valves.

A gasket is any sealing material between two metal parts, designed to provide a tight seal between the surfaces.

Anti-seize additive - a coating that reduces the risk of metal scuffing in threaded connections exposed to high temperatures (for example, the bolts of the exhaust pipes of a car).

R

Radial play is the play of a part in the radial direction relative to the axis of rotation.

A radiator is a device for heat dissipation, a heat exchanger. In an engine cooling system, the radiator is designed to transfer heat from the coolant to the atmosphere.

Collapse (camber, from English. Camber angle) — the angle between the vertical and the plane of rotation of the wheel. Camber is considered negative if the wheels point upwards, and positive if the wheels point upwards.

A transfer case is a unit for distributing torque from the engine to several drive mechanisms, which in most cases also increases the number of gears in the transmission. For example, in off-road vehicles the transfer case:

• Distributes torque between the drive axles in such a way as to ensure the best possible vehicle maneuverability without the occurrence of a negative phenomenon - "power circulation" in the transmission;
• Increases torque on the drive wheels within the limits required to overcome the rolling resistance of the wheels when driving on poor roads and off-road, as well as on steep climbs;
• Ensures stable movement of the vehicle at low speed when the engine is operating at maximum torque.
• Cylinder bore boring is the increase in the internal diameter of the cylinder bore by mechanical processing to the repair size (see "Repair size").

Grinding is the process of renewing the valve seating surfaces and valve seats in the cylinder head.

Adjusting washers are washers of a certain thickness, designed to adjust the geometric parameters of the mechanism (gaps, runouts, etc.).

Voltage regulator (voltage stabilizer) - an electrical device that receives power from an external power source and produces at its output a voltage that is independent of the supply voltage (provided that the supply voltage does not exceed the permissible limits).

A relay is an electrical device designed to close and open electrical circuits with high current, controlled by low currents.

Repair size is a standardized size, increased relative to the nominal size, used during major repairs of a particular unit (for example, piston-cylinder liner systems). Depending on the degree of increase in size relative to the nominal, there are first, second, third, etc. repair sizes with a certain step (for example, 0.5 mm).

WITH

An LED is a semiconductor device that emits light when an electric current is passed through it.

A spark plug is a device used to ignite the fuel-air mixture in a wide variety of heat engines. Spark plugs are used in gasoline internal combustion engines. The ignition of the combustible mixture is produced by an electric discharge with a voltage of several thousand or tens of thousands of volts, which occurs between the spark plug electrodes. The spark plug fires at a specific point in each cycle of engine operation.

Free play is the amount of travel before the action begins, caused by loosening of the rod connections or other elements of the mechanism. For example, brake pedal free travel is the distance the brake pedal travels before the brake mechanisms begin to engage.

Seasonal oil (Monograde Oil) - motor oil that meets the requirements of more than one viscosity grade according to the SAE classification (Society of Automotive Engineers) (see SAE viscosity grades), can be used in a more limited temperature range than dual viscosity grade oils.

Charging system - a system designed to charge a vehicle's battery.

Starting system - a system designed to start an internal combustion engine by forcibly rotating the crankshaft with an electric motor (starter).

Fuel vapor recovery system - a system designed to capture fuel vapors from the fuel system and prevent them from escaping into the atmosphere.

The engine management system is an electronic system designed to control the processes of intake of the fuel-air mixture, ignition and exhaust gas release in an internal combustion engine.

Resistance is a value that characterizes the properties of a conductor.

Starter (in an internal combustion engine) — a device that rotates the crankshaft to start the engine.

Compression ratio is the ratio of the volume of the above-piston space of the cylinder when the piston is at the bottom dead center (BDC) to the volume of the above-piston space of the cylinder when the piston is at the top dead center (TDC), that is, to the volume of the combustion chamber. The concept of compression ratio should not be confused with the concept of compression, which means (at a certain structurally determined degree of compression) the maximum pressure created in the cylinder when the piston moves from bottom dead center (BDC) to top dead center (TDC) (for example: compression ratio -10:1, compression - 14 atm.).

A retaining ring is an elastic ring used to prevent movement of cylindrical parts and shafts. The internal retaining ring is installed in a groove in the housing; outer retaining ring - into the groove in the outer cylindrical surface of the axle.

Toe-in is the angle between the direction of travel and the plane of rotation of the wheel. Very often they talk about the total toe-in of two wheels on one axle. Some vehicles allow you to adjust the toe-in of both the front and rear wheels.

T

Fuel-air mixture is a charge consisting of a mixture of fuel and air, supplied to the cylinder of an internal combustion engine.

Turbocharger (gas turbine supercharger) - a device that uses the energy of exhaust gases to force air or a fuel-air mixture into an internal combustion engine. For low power engines (automobile) turbochargers with a centripetal turbine are used, and on high-power engines (tractor, diesel locomotive, marine) - with an axial turbine. The compressor is always centrifugal, since the axial compressor has a more complex design and a tendency to surge.

U

Valve opening angle is the position of the crankshaft at which the valve opens (inlet or outlet).

The transverse inclination angle (KPI) is the angle between the vertical and the projection of the steering gear axis onto the transverse plane of the vehicle. This angle ensures self-alignment of the steering wheels due to the weight of the vehicle.

The carbon filter is the main component of the fuel vapor recovery system, consisting of activated carbon granules designed to capture fuel vapors from the fuel system and prevent them from escaping into the atmosphere.

A sealing ring is a sealing element in the form of a ring made of an elastic material (for example, rubber).

Thrust washer - a washer installed between two components located on an axis (shaft) to ensure the required amount of axial clearance.

X

Honing is a type of abrasive machining using honing heads (hones). It is primarily used to machine internal cylindrical bores (2 mm and larger) by combining rotary and reciprocating motions of the hone with sliding abrasive stones attached to it, while generously spraying the work surface with a cutting fluid. One of the types of finishing and finishing machining. Allows you to obtain a hole with a deviation from cylindrical shape of up to 5 µm and a surface roughness of Ra=0.63+0.04.

C

The timing chain is a chain designed to synchronously transmit rotation from the crankshaft to the camshaft(s) of the engine.

Cetane number is a characteristic of the flammability of diesel fuels that determines the ignition delay period of the mixture (the time interval from the injection of fuel into the cylinder until the start of its combustion). The higher the cetane number, the shorter the delay and the more calmly and smoothly the fuel mixture burns.

Coil spring (helical, spiral) - a cylindrical spiral made of elastic wire of various sizes, designed to accumulate and absorb mechanical energy, which is widely used in car design.

Ch

Rotational speed is a value characterizing the rotational speed of a body (shaft). It is measured in revolutions per unit of time.

Worm gear (gear-screw transmission) — a mechanical transmission achieved by the engagement of a worm and a worm wheel mated with it.

Sh

A ball bearing is a bearing consisting of two rings (internal and external) made of hardened steel and a set of balls between them.

A connecting rod is an element of a crank mechanism designed to transmit mechanical energy from the piston to the crank (crankshaft).

Connecting rod bearings are bimetallic bearings that are installed in the lower head of the connecting rod to reduce friction between the connecting rod and the crankshaft.

Shimmy (wobbling) is an effect that occurs at speed when the front wheel of a motorcycle or car beats, causing the steering wheel to beat and the trajectory of movement to "wobble" from side to side. Shimmy is dangerous because it occurs not at low speeds, but only at high speeds. It requires immediate action from the driver, but even that does not guarantee success.

CV joint (constant velocity joint) - a mechanical device that provides transmission of high torque at rotation angles of up to 70 degrees relative to the axis. It is used in the drive systems of passenger cars with independent suspension on the front and, less commonly, rear wheel axles.

A caliper is a high-precision measuring instrument designed for measuring internal and external diameters.

E

An electrolyte is a substance whose solution or melt conducts electric current. In automotive applications, it is a solution of sulfuric acid used in a battery to cause a chemical reaction that converts energy into electrical energy.

An electronic control unit is a processor that controls the electronic components of a particular system (for example, by ignition of the engine).