The rack and pinion gear converts the rotational motion of your steering wheel into the linear motion that’s necessary to turn the wheels. It’s used on vehicles equipped with rack and pinion steering.
This gear set is usually enclosed in a metal tube with each end of the rack sticking out from the tube. A tie rod connects to each end of the rack. Meanwhile, the pinion gear is usually attached to the steering shaft.
When you turn your steering wheel, the gear spins, activating the movement of the rack.
The radiator helps get rid of excess heat in the engine by dispersing coolant, a mixture of antifreeze and water. This mixture absorbs the heat produced by the engine before circling back to the radiator, which cools the fluid by blowing it with air from outside the vehicle.
You can typically find the radiator underneath the hood, often poised in front of the engine.
Radiators, Fans, Cooling Systems & Components
A radiator air seal is the plastic assembly that surrounds a vehicle’s radiator and radiator support. Unlike the radiator support that holds the radiator in place, the radiator air seal helps improve cooling by sealing the gaps surrounding the radiator. This allows more air to flow through the radiator, which can be helpful when your vehicle doesn’t have much air flow when it’s traveling at low speeds. Without the radiator air seal, your radiator might not dissipate heat as effectively.
The radiator cap is the cover of the radiator and seals the filler neck. You must replace the cap if the component develops an issue that leads to problems like coolant leaks and the engine overheating. The radiator cap is found on the top of the radiator, and it is made from either metal or plastic. The radiator relies on the cap to stop the loss of coolant, keep the cooling system at the right pressure, and raise the coolant’s boiling point.
The Radiator Cap Adapter is a small tool that screws onto the coolant reservoir cap on one end while the other end has a standard radiator cap opening that you can connect to a radiator pressure tester. It allows you to verify that your pressure relief valve is functioning properly without having to remove the radiator cap. Radiator cap adapters provide an air-tight seal that prevents leaks from the radiator while making it easier to attach handheld pressure pumps for accurate coolant system testing.
The Radiator Coolant Hose Adapter is an adapter that connects the smaller upper radiator hose to the larger lower radiator hose. The smaller diameter of the upper radiator hose helps to minimize the vacuum strength at the inlet to the water pump, which in turn helps prevent air bubbles from forming in the coolant. The coolant passes through the radiator coolant hose adapter in order to flow from one hose to the other without compromising the water pump.
The radiator drain plug is a part that lets you drain coolant from the radiator. This part might be needed if you’re dealing with coolant leaks. The radiator drain plug is mounted on the bottom edge of the radiator, and it fits tightly to prevent coolant leaks. The radiator needs the radiator drain plug for some maintenance and repair jobs that require emptying it of coolant.
The Radiator End Tank is a part of the radiator that connects the radiator core to the inlet and outlet hoses. It allows the coolant to flow through the radiator by providing a sealed enclosure that directs the airflow across the radiator core. You’ll find different designs of radiator end tanks on the market, each with its own set of advantages. They’re typically made from durable, heat-resistant materials, such as plastic, aluminum, and steel.
The Radiator End Tank Gasket is a thin band made of rubber or cork that fits between the radiator and the end tank. It seals the connection between the end tank and the radiator and prevents radiator fluid leaks between the joints. Radiator gaskets help keep the coolant flowing smoothly through the system at the right pressure, which keeps the engine from overheating. If the radiator end tank gasket is damaged in any way, it could lead to leaking coolant and an overheating engine.
The Radiator Fan is an important part of the cooling system. Located between the radiator and the engine, it pulls cold air through the radiator core to the engine. Radiator fans help keep the engine cool even when the vehicle is stationary or moving too slowly for air to pass through the grille. You can find different types of radiator fans on the market, such as mechanical, electrical, single, and dual radiator fans.
A radiator filler neck is the opening on top of a radiator that allows you to fill it up with coolant or water. The filler neck protrudes from the actual radiator, giving you easier access to the radiator’s opening. If the radiator filler neck didn’t exist, the radiator cap would be flush with the radiator, which can make it more difficult to access on some vehicles. Some radiator filler necks can come with a cap. Meanwhile, some filler necks don’t come with a cap, allowing you to purchase a compatible cap of your choice.
The Radiator Fitting is a small, threaded component that usually connects to the radiator hose or inlet. It’s usually made of aluminum to match other parts of the radiator. Radiator fittings come in different sizes and are usually sold with a compression nut or screw compatible with its partner valve. You can also find radiator fittings sold by piece or in a kit together with radiator hoses for easier installation.
A Radiator Flush Kit contains various tools used to flush a radiator. A typical kit includes a splash deflector tube, a pair of hose clamps, a backflow preventer coupler, and a flush-and-fill tee. A radiator flush kit offers the advantage of easier and quicker flushing for any type of vehicle. The kit can be used in tandem with a garden hose. Materials and quality determine the price of a kit.
The radiator hose is a large-diameter rubber tube that carries engine coolant to the engine and radiator before it goes back to the water pump.
There’s usually an upper and lower radiator hose in an engine. The lower radiator hose is reinforced with a spring to prevent it from being sucked closed since it’s attached to the suction side of the water pump.
The Radiator Hose Kit contains various radiator hoses, such as upper, lower, bypass, and heater hoses. This part might be needed if you have multiple damaged or worn-out radiator hoses that require replacement. The contents of a radiator hose kit connect the radiator with engine parts, and the hoses transport coolant fluid back and forth. The cooling system needs the radiator hoses in this kit
The Radiator Hose O-Ring a ring-shaped, synthetic component that fits between radiator hose sections. There are multiple rings on the same radiator hose. The rings come in different sizes to fit different sections of the hose. These rings create a secure seal that prevents any coolant from leaking through the gaps between sections. They can be sold one at a time for specific sections or in a set.
Radiator insulators are pieces of rubber that sit between the radiator and the radiator support. A radiator typically has 4 radiator insulators that are mounted on the radiator’s contact points. These rubber pads are meant to cushion the radiator, shielding it from the harsh vibrations that come from the nearby engine which can damage the radiator. Having rubber cushions also prevents the radiator from making buzzing noises as the engine runs.
A Radiator Mount stabilizes the radiator whenever the vehicle is moving. It provides structural support to keep the radiator in place and prevents it from vibrating excessively.
Most radiator mounts are made from steel or aluminum to provide maximum durability.
The radiator mount bracket is a part that secures the radiator to the engine bay, provides structural support, and stabilizes it. This part might be needed if the stock or current radiator mount brackets have developed cracks or become loose. Radiator mount brackets are mounted on the frame and prevent movement, vibration, and wear. The radiator relies on its mount brackets to keep it properly aligned.
The Radiator Mount Bushing is a small part that secures and isolates the radiator from the vehicle’s frame. Most bushings are made of rubber or polyurethane material, which provides a cushioning effect that protects the radiator from damage caused by engine movement and road vibrations. Bushings also absorb transmission noise while maintaining the radiator’s proper alignment and position. This results in optimal airflow, allowing the radiator to effectively cool the engine.
The Radiator Petcock is a drain valve that, when twisted and opened, helps facilitate a radiator flush. When opened, it allows coolant and other impurities to drain out of the radiator. Radiator petcocks are short and cylindrical, made of plastic, and have grooves on the exterior of their body. The tops of some radiator petcocks have raised crosses or wings to make twisting them out easier. Others have a depressed cross instead and require the use of a screwdriver.
The radiator shroud is a plastic or metal frame that fits around the radiator. The shroud is designed to have a space in the middle for the fan blades to rotate freely.
The radiator shroud also helps the radiator channel airflow through the blades instead of the sides.
The radiator support is a steel, plastic, or aluminum frame that holds the radiator in place. It also attaches the radiator to the side aprons and the upper/lower rails of the engine assembly frame.
The radiator support helps maintain the proper alignment and positioning of the radiator, as well as the cooling fan and the other components in the front of the vehicle.
The radiator support bracket is the metal frame inside your vehicle’s engine compartment that holds the radiator. The support bracket plays a major role in securing and stabilizing the radiator behind the vehicle’s grille assembly. The brackets provide structural support and ensure the radiator is properly aligned with other components like the cooling fan and hoses. In a collision, the support bracket can also protect the radiator from being damaged. Because of this, the radiator support bracket is a common component replaced after a crash.
The radiator support cover helps protect the cooling system from vibrations and exposure to the elements. This part might be needed if the current or stock radiator support cover has become worse for wear. Radiator support covers are found on top of the vehicle’s radiator and block contaminants like dirt and water from reaching the cooling system. The radiator and other cooling parts can stay stable thanks to the radiator support cover bracing it.
The Radiator Support Mounting Pad is a rubber pad that cushions and supports the radiator body. The rubber material is durable, heat-insulated, and provides all-around protection for the radiator. It can be sold individually or as part of a set with the bolts necessary to attach it to the radiator. Radiator support pads are specifically designed for heavy-duty use and can come in different shapes and sizes.
The Radiator Support Reinforcement is a piece that attaches to the radiator support to help it hold down the radiator and the radiator cover. This keeps them from moving too much while the vehicle is in motion. If the radiator moves too much, it can end up misaligned along with the other engine parts. The radiator support reinforcement is made of metal and has slots for bolts or screws. These reinforcements come in different designs depending on the vehicle’s make and model.
The Radiator Support Splash Shield is a scrape guard that protects the radiator, condenser assembly, cooling fan system, and other surrounding parts. It prevents damage caused by water, rocks, and other debris, which helps prolong the radiator’s lifespan. Like most types of splash shields, radiator support splash shields are made from metal or heavy-duty plastic, but they can sometimes crack from bumping into hard objects. This can lead to radiator damage and coolant leaks.
The Radio Capacitor lets the operator select a specific frequency. When integrated with an inductor, the capacitor is capable of forming a resonant circuit that can oscillate at a particular frequency.
The radio control knob is found on many vehicle radios or head units. The control knob is regularly used to either control the speaker volume or change the radio station. Some radio control knobs can come in pairs. Radio control knobs can also have different materials. Some are made from metal, but most are made from plastic. After years of use, control knobs can come off and get lost, which can make it difficult to control the radio.
The Radio Control Module controls and manages certain functions related to your vehicle’s radio system. The specific function of a radio control module can vary depending on your vehicle and the specific radio system installed.
The radius arm, also known as the radius rod, torque arm, or dog bone, refers to suspension links that limit the range of movement of the vehicle’s axles without getting in the way of its articulation.
The radius arm helps keep the axles centered to improve maneuverability, all while preventing tire wear and keeping the wheels aligned. It also supports the torque from the transmission and absorbs vibrations.
A radius arm bracket is a component of a truck or SUV’s suspension system that secures the radius arm, which helps control axle movement during acceleration and braking. This bracket keeps the radius arm in place and allows it to turn as needed.
The Radius Arm Bushing dampens shocks and vibrations passing through the radius arm, preventing the disruptive jolts from reaching the vehicle’s frame. This part might be needed if you experience increased vibrations while driving over rough surfaces because of damaged or worn-out cushions. Radius arm bushings are mounted on a vehicle’s radius arms, reducing friction and wear on suspension parts. Radius arms and control arms benefit from the bushings cushioning them from vibrations.
The radius rod bushing supports the radius rod, which is a suspension component that controls a wheel’s fore and aft motion. Like any bushing, the radius rod bushing prevents vibrations from transferring between components. Each radius rod typically has two bushings, one connecting the rod bushing to the axle, and another connecting the rod to the chassis.
A Rain Sensor Module is a device that automatically adjusts the windshield wiper speed based on rainfall intensity. It’s typically located behind the windshield near the rearview mirror with infrared LEDs and a photodiode as the main components.
The rear hatch latch is basically a door latch for the rear hatch in a hatchback or SUV. The rear hatch latch has small claws that release to open the vehicle’s hatch. The rear hatch latch works in conjunction with an anchor that’s located at the bottom of your rear liftgate. This part typically has an electric motor or solenoid inside that disengages the claws when it receives a signal. Disengaging the rear hatch latch usually involves pressing a button on the dashboard or above the rear license plate.
The rear hatch release solenoid is a part that controls the release latch for the rear hatch. This part might be needed if the current or factory-issue rear hatch release solenoid is having an issue or stopped working. Rear hatch release solenoids are mounted on a vehicle’s rear hatch. The rear hatch can open on your command because of this part.
The Rear Light Harness Connector is a connector that plugs directly into the rear light harness. You can buy connectors individually or get a connector kit that includes all the terminals, seals, and other installation tools you’ll need to mount it on your rear light’s harness. Connectors can vary according to the number of wires, terminal types, shapes, and other factors, so you’ll have to check which one’s compatible with your ride.
The Rear Main Seal is designed to seal oil from leaking around the crankshaft at different temperatures. It comes in different sizes, styles, and materials. Some commonly used materials include Buna-N, Viton (fluorocarbon), and Teflon (polytetrafluorethylene/PTFE).
A rear view mirror is a vital safety component that allows drivers to see what’s behind their vehicles. This gives them better awareness of other vehicles, objects, or pedestrians at their rear. This helps in safely changing lanes, merging into traffic, or reversing.
A Rear Window Defogger Relay triggers the heating element that thaws out snow and frost from the rear window.
The rear window defroster relay activates the compressor switch, reversing the heat pump valve. After which, the interior electric heating element turns on and prevents the fan and outdoor coil from spinning.
The Rear Window Glass is a window that’s located in the back of the vehicle. It is often made of tempered glass, which is approximately four times more durable than regular glass.
This window gives drivers a view of what’s behind them, prevents vehicle theft, and keeps road debris and rain out of the vehicle.
A Rear Window Seal is a rubber seal that forms a barrier to prevent air and moisture from entering the cabin.
The Rear Window Wiper Motor Connector connects the rear window wiper motor to a power source. This provides the motor with the power needed to mobilize the rear window wiper. This connector is usually found in the rear of the vehicle, attached to the rear window wiper.
A Receiver Tubing is a component used in towing. It’s often welded onto a vehicle’s frame or bumper to extend an existing receiver or create custom towing equipment. A receiving tubing lets you attach accessories like trailer hitches or bike racks.
A reference sensor monitors the position and speed of engine parts, such as the crankshaft and camshaft. The crankshaft position sensor is a type of reference sensor. The data gathered by the reference sensor is used to manage fuel injection and ignition timing.
Refrigerant Oil lubricates the compressor’s internal components to ensure smooth operation. It also acts as a sealing agent for rubber parts, absorbs heat, and prevents electrical damage in some hybrid vehicles.
Relay Modules are electro-magnetically operated switches that make and break the flow of current in a circuit. When a low amperage current passes through one circuit, the relay switches and permits a greater current through another line.
The Remote Starter is a device that’s used to start the engine of a vehicle remotely. It also allows drivers to activate and deactivate features, such as locks, heating or air conditioning, and alarms.
Some remote starters are apps that can be downloaded on a mobile device, but most are remote fobs.
A Repair Sleeve is a thin metal sleeve that’s inserted onto a worn or damaged shaft as a quick and easy way to repair the shaft. Repair sleeves are usually made of hard chrome-plated stainless steel.
The Resonator is a component that modulates the noise generated by a vehicle’s engine. It is different from the muffler because it doesn’t reduce noise in the exhaust. Instead, it changes the sound of the noise, typically by eliminating high-pitched sounds. The resonator can be found in the vehicle’s exhaust system.
A retaining plate keeps the axle in its housing. Vehicles have varying specifications when it comes to replacing a retaining plate. Failure to install the right plate can lead to axle seal leaks.
The Rev Limiter Chip is a device that helps restrict the maximum number of revolutions per minute (RPM) an engine can make. It’s designed to prevent overspeeding, which can cause critical engine parts to fail prematurely.
If the RPM needle reaches the red line on the tachometer, the rev limiter will restrict fuel flow to the engine. Regular operating conditions will return once the gauge displays regular RPM figures.
The Reverse Idler Gear is typically placed between the driving and driven gears to ensure consistent rotation for smoother and more efficient power transmission. It’s a component commonly found in manual vehicle transmissions.
The Ring and Pinion Bearing Kit includes the parts necessary to set up and install the ring and pinion bearings. These bearings help the drive shaft rotate, letting the differential direct power to the wheels of the vehicle.
A ring and pinion bearing kit also contains the bearings themselves, screws to secure them, and other miscellaneous components required for installation.
The Ring Gear is a large, circular gear attached to the differential. It’s responsible for transfering power from the engine to the wheels. Ring gears are designed to withstand the constant friction of the drivetrain, but they can wear over time and cause performance-related issues. The ring gear of the rear axle surrounds the differential gear train’s housings, where it divides the torque between the two wheels. This allows one of the wheels to turn faster than the other when rounding a corner.
The Roadside Emergency Kit contains tools and supplies designed to help drivers deal with emergencies that require specialized equipment. They typically include jumper cables, gloves, screwdrivers, reflective triangles, reflective vests, and more. The kit inclusions vary from product to product.
The Rocker Arm Shaft transfers motion from the crankshaft to the intake and exhaust valves in the engine. It serves as the pivot point for the rocker arm, allowing it to open and close the valves at the correct times to ensure proper engine operation. Because it needs to withstand constant motion and high pressure levels, it is typically made of a durable material like steel.
A Rocker Panel is a narrow strip of metal or plastic that’s typically attached below the doors. It provides structural integrity to the vehicle by helping absorb collision impact and minimizing damage to the passenger side.
A rocker panel can also serve as an aesthetic piece.
Rocker Repair Panels are components welded onto rocker panels to repair corrosion damage. These repair panels also keep the chassis rigid, making the suspension work better. These put less stress on a vehicle’s frame and reinforce the latter’s structural integrity.
Rocker repair panels are installed on rocker panels found under the door, beneath the front and rear wheels of a vehicle.
The rod bearing is a split-sleeve bearing that holds both the connecting rod and the crankshaft as they rotate in the engine. The bearing’s upper half links to the connecting rod’s larger end. The bearing’s lower half links to the rod bearing cap. There’s a pinhole on the rod bearing’s top half. Oil flows through the hole to lubricate the crankshaft. This design keeps the crankshaft spinning freely inside the bearing while keeping it from overheating. Every piston and connecting rod assembly pair in an engine has its own rod bearing.
Roll bars are metal bars installed in racing and performance vehicles to improve its structural rigidity and to protect the vehicle’s occupants in case of a rollover. Roll bar padding is a type of padding that goes around roll bars. They’re meant to protect the driver or passengers by providing energy absorption upon impact. The pads wrap around the metal tubing, allowing owners to easily install them.
The roll bar seal is a protective cover for the roll bar that keeps the bar dry and safe during bad weather and potential accidents. This part might be needed if the existing roll bar seal has developed issues like cracking and rotting. Roll bar seals are mounted on ends of the bar. The roll bar needs road bar seals as protection from moisture that can cause corrosion.
The Roll Bar Storage is a bag that was specifically designed to attach to the roll bar with easy-to-use straps and buckles. Roll bar bags come in different colors, shapes, and sizes, but they’re usually big enough to carry tools and other small gear. You can find roll bar storage bags made of heavy-duty canvas or durable polyester nylon material. They usually have handles that make it easy to carry them around once they’re detached from the roll bar.
The Roll Pan is a type of replacement bumper made of metal or fiberglass. It’s designed to create a more sleek, seamless look by forming a rounded bottom at the front or back of the truck. This part is sold in a sleek black color that can be painted to suit any vehicle’s paint job. Whether it’s legal to replace a vehicle’s bumper with a roll pan depends on the type of vehicle and local state laws. Roll pans are most often used on trucks.
A Roof and Top Weatherstrip Seal prevents water, air, and noise from entering the cabin by sealing the gaps between the roof and the vehicle’s body. It’s typically made from durable rubber or synthetic materials that withstand various weather conditions.
A Roof Brace is used to add structural support to the vehicle without adding too much weight.
Roof molding is one of the many decorative and protective pieces of moldings on your vehicle. Unlike body moldings that can somewhat protect a vehicle’s side from scratches, roof molding is purely decorative. It’s meant to give the vehicle’s roof some lines that can help accentuate its shape. Since most moldings are black, the outline can also give the vehicle some character. Roof molding is typically made from plastics like polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), or polycarbonate.
The Roof Panel is a part of your vehicle’s roof that protects you and your passengers from the elements while improving your car’s aerodynamics. It’s typically made of durable material, such as sheet metal, aluminum, or plastic. Some vehicles have soft tops with roof panels that are usually made of vinyl, canvas, and other textile materials. Roof panels can vary in size, shape, and design, including some that can even be removed completely to let the wind in.
The Roof Rack is a metal luggage-carrying accessory that attaches to the roof of a vehicle via a roof rack mount. They allow the vehicle to carry more things without crowding the cabin or overfilling the trunk. While typical roof racks primarily hold luggage, other designs and roof rack accessories allow the rack to hold more specialized items such as bikes and canoes. Many roof racks have universal designs that suit any vehicle type, but other roof racks have designs that attach best on specific vehicles like hatchbacks or off-road trucks.
The roof rack mount is a part that attaches the roof rack to the vehicle’s roof. This part might be needed if you want to install roof racks on your vehicle or if the existing mounts have worn out. Roof rack mounts are found on a vehicle’s roof, and they ensure that the roof racks don’t budge. The roof racks rely on their mounts to keep them attached to your vehicle, no matter how bumpy the ride gets.
A Roof Rail Bushing Kit is a set of bushings that secure the roof rail, preventing it from vibrating excessively.
TheRoof Rail Seal is a component that seals the gap between the vehicle’s roof and its doors/windows. It prevents water, wind, and noise from entering the vehicle for a quieter and more comfortable ride. It’s typically installed along the roof rail, where the roof meets the doors.
A Roof Weatherstrip Seal is a strip of rubber-like material that lines the edges of your vehicle’s roof, particularly where it meets the windows and doors. It provides a tight seal to prevent water, air, and debris from entering the vehicle through the roof gaps.
A revolutions per minute (RPM) sensor is a device that measures the number of revolutions the crankshaft makes in a minute.
The RPM sensor feeds information to the powertrain control module, helping it calculate the exact position of the crankshaft. This helps the cylinders fire in the correct order.
An engine’s RPM is displayed on a different device called the tachometer. In a manual transmission engine, drivers use the RPM readings to determine the right time to shift gears.
The running board cover is a set of stamped steel that covers the running board’s mounting brackets. The mounting brackets are the pieces of steel where the actual running board is installed. These mounting brackets and the running board cover are the parts that protrude outward. These steel covers give the running board’s mounting brackets better dimensions, which helps the vehicle look more stylish.
The running board extension arm is a component that increases the running board’s total drop, making it easier to step on and off the board. This part might be needed if you need to replace faulty running board extension arms or adjust the board’s total drop with longer or shorter extension arms. Running board extension arms are found between the vehicle’s side and the running boards. Running boards use the extension arms as connectors as well as lowering adjusters.
The Running Board Gap Strip is a trim seal gasket that covers the space between molded step boards and body panels. Filling in this small gap prevents water, dirt, and other debris from collecting between the step boards and body panels, making it easier to clean your vehicle. Most gap strips are also easy to install and don’t require drilling. Like other drivers, you can also use running board gap strips as a mounting spot for additional lights.
The Running Board Motor is an electric motor that attaches to an electric running board. These electric running boards can retract when not in use, and drop down to provide an easy step for passengers to enter a taller vehicle. The running board motor powers this movement, dropping the running boards only when a door opens. This allows the electric running board to sit flush with the vehicle’s body when not in use.
Running Board Mounting Kits are a collection of tools and components used to install running boards on vehicles. Running boards are stepping surfaces installed along the sides of a vehicle, helping drivers or passengers get in or out of the cabin easily. They’re often made of durable materials like stainless steel, aluminum, and heavy-duty plastic.
Running Boards are installed on the sides of a vehicle to provide an extra step for easier access to units with higher ground clearance. They also serve as a means of protection, guarding the doors and side panels of a vehicle from potential damage that’s typically brought about by road debris.
A Running Light is a lighting device that normally activates when the engine is on or running. A running light is a low-intensity lighting fixture that can help prevent daytime collisions. Unlike headlights, running lights are not intended for illuminating the road under low-visibility conditions.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.