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Cross-drilled Crank

A crankshaft having two oil passages at right angles to each other in the main journal to provide extra lubrication for the main and rod bearings.

Cross-drilled Rotors

Disc brake rotors that have been drilled through to allow for outgassing, a phenomenon that was common on vintage race cars, but that rarely occurs on modern automobiles. Today, many disc brake rotors are cross-drilled for cosmetic reasons, since they look "racy" and often are visible through a vehicle's wheels. Cross-drilling also may halp vehicles stop after they go through a puddle. Typically, water gets trapped between a vehicle's rotors and its brake pads, so they can't make contact with the rotors of the vehicle. The cross-drilled holes give the water some place to go, so the pads are able to contact the rotors.

Cross-groove Joint

A disc-shaped, inner, constant-velocity universal joint that bolts to a transaxle stub flange and uses balls and V-shaped grooves on the inner and outer races to accommodate the plunging motion of the half-shaft.

Cross-section Width

The width of the bottom of the tire, measured in millimeters.

Crossbolt Main Cap

A main-bearing cap that is secured with two down-facing bolts and two bolts that intersect at right angles.

Crossdrilled Rotors

See cross-drilled rotors.

Crossfire

The electromagnetic-induction spark that can be transmitted in another wire close to the wire carrying the current.

Crossfire Injection

A type of throttle-body injection system that uses two injectors mounted on the manifold. Each injector feeds a cylinder on the opposite side by using a crossover port.

Crossflow Head

A cylinder head having its intake ports on one side and the exhaust ports on the other side.

Crossflow Radiator

A radiator in which the coolant flow is from one side to the other.

Crosshatch

1. A honing pattern that is required in a cylinder to maintain the correct amount of oil retention and to facilitate ring rotation. 2. A series of crisscrossing lines that indicate a specific area in a drawing or diagram.

Crossmember

A part of the underbody structure of a vehicle that extends from one side of the frame to the other or from one side of the unibody to the other. Usually removable to gain access for repair.

Crossover Box

A tool box that sits at the front of a pickup's bed, right behind the cab, and rests atop each bed rail. This is the most common truck box design. Most crossover boxes do not extend all the way down to the bed floor, so you can slide a ladder, lumber or other long loads under the tool box.

Crossover Network

An electrical circuit that routes different frequencies to the woofer, midrange, and tweeter in a multiple-speaker system.

Crossover Network

A network of filters that divides the incoming audio signal into different frequency bands. It is designed to send high frequencies to the tweeters only, and to send low frequencies to the woofers or subwoofers. A low-pass crossover allows only frequencies below a certain crossover point to be amplified, while a high-pass crossover allows only frequencies above a certain crossover point to be amplified. Crossovers installed between an amplifier and a speaker are called speaker-level crossovers. Crossovers installed between a head unit and an amplifier are called pre-amp-level crossovers. Some speakers and speaker component systems will have built-in crossover networks. For example in a coaxial speaker, a crossover (or capacitor) is used to prevent bass frequencies from going to the tweeter.

Crossover Pipe

A pipe used to connect both sides of an exhaust system to equalize the pressure.

Crossover Tube

A tube that is used to transmit liquid or gases in or around an engine.

Crowd

An accelerator action that maintains a constant manifold-vacuum reading, requiring a progressive opening of the ;throttle as the vehicle speed is increased.

Crown

The top surface of a piston.

Crown Gear

The ring gear in a differential.