Crankshaft vs. Driveshaft: What's the Difference?
By Harlon Moss & Janet White || Updated on May 20, 2024
A crankshaft converts linear motion into rotational motion in an engine, while a driveshaft transmits rotational power from the engine to the wheels of a vehicle.
Key Differences
A crankshaft is a crucial component within an engine, converting the linear motion of pistons into rotational motion to drive the vehicle. It is directly connected to the pistons via connecting rods. On the other hand, a driveshaft transmits the rotational power generated by the engine to the wheels, enabling the vehicle to move. This shaft typically connects the transmission to the differential in rear-wheel-drive vehicles.
The crankshaft operates within the engine block, enduring significant stresses due to the force of the pistons. It must be precisely balanced to prevent vibrations that could damage the engine. Conversely, the driveshaft is located beneath the vehicle, extending from the transmission to the differential. It must be strong enough to handle the torque produced by the engine while being lightweight to reduce the vehicle's overall weight.
In terms of materials, crankshafts are usually made from forged steel or cast iron to withstand high pressures and temperatures within the engine. Driveshafts are typically constructed from steel, aluminum, or carbon fiber, balancing strength and weight considerations to efficiently transmit power without excessive flexing or breaking.
The maintenance of a crankshaft involves ensuring proper lubrication and checking for any signs of wear or damage, as it is integral to the engine's performance. The driveshaft requires periodic inspection for balance and alignment, ensuring the smooth transmission of power to the wheels without causing vibrations or undue stress on the vehicle's components.
Crankshafts and driveshafts, though both essential for the vehicle's operation, serve distinctly different roles in the powertrain. The crankshaft transforms and manages the engine's power, while the driveshaft ensures this power reaches the wheels to propel the vehicle forward.
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Comparison Chart
Function
Converts linear motion to rotational motion
Transmits rotational power to the wheels
Location
Inside the engine block
Beneath the vehicle, from transmission to differential
Connection
Connected to pistons
Connects transmission to differential
Material
Forged steel or cast iron
Steel, aluminum, or carbon fiber
Maintenance
Lubrication and wear inspection
Balance and alignment inspection
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Crankshaft and Driveshaft Definitions
Crankshaft
Converts linear motion of pistons to rotational motion.
The crankshaft rotates, driving the vehicle forward.
Driveshaft
Transmits power from transmission to wheels.
The driveshaft ensures power reaches the rear wheels in a truck.
Crankshaft
Made from durable materials like forged steel.
High-performance cars often use specially forged crankshafts.
Driveshaft
Made from steel, aluminum, or carbon fiber.
Lightweight driveshafts improve vehicle efficiency.
Crankshaft
Connected to pistons via connecting rods.
Each piston is linked to the crankshaft, converting its up-and-down motion.
Driveshaft
Located beneath the vehicle.
Regular inspection of the driveshaft is necessary for smooth operation.
Crankshaft
Located within the engine block.
Damage to the crankshaft can severely affect engine performance.
Driveshaft
Connects transmission to the differential.
In a rear-wheel-drive car, the driveshaft runs from the gearbox to the axle.
Crankshaft
Critical for engine's power delivery.
Without a crankshaft, the engine cannot convert power efficiently.
Driveshaft
Essential for vehicle movement.
A faulty driveshaft can lead to severe driving issues.
Crankshaft
A shaft that turns or is turned by a crank.
Driveshaft
A rotating shaft that transmits mechanical power from a motor or an engine to a point or region of application.
Crankshaft
A rotating shaft that drives (or is driven by) a crank.
Driveshaft
A shaft used to transmit rotary motion.
Crankshaft
(of a straight bolt or rod) To deform in such a manner that part of the rod or bolt is displaced sideways, offset from the longitudinal axis of the part, but remains parallel with the part's main longitudinal axis, with the final shape somewhat resembling a crankshaft.
Driveshaft
A rotating shaft that transmits power from the engine to the point of application.
Crankshaft
A rotating shaft driven by (or driving) a crank
Driveshaft
A rotating shaft that transmits power from the engine to the point of application
FAQs
What is a driveshaft?
A driveshaft transmits rotational power from the engine to the wheels of a vehicle.
Where is the driveshaft located?
The driveshaft is located beneath the vehicle, connecting the transmission to the differential.
How does a driveshaft function?
It transmits the rotational power from the transmission to the wheels.
What materials are crankshafts made of?
Crankshafts are typically made from forged steel or cast iron.
Where is the crankshaft located?
The crankshaft is located within the engine block.
What kind of maintenance does a driveshaft require?
Driveshafts require balance and alignment inspection.
What connects to the crankshaft?
The pistons connect to the crankshaft via connecting rods.
What is a crankshaft?
A crankshaft converts the linear motion of pistons into rotational motion within an engine.
What materials are driveshafts made of?
Driveshafts are made from steel, aluminum, or carbon fiber.
Why is the crankshaft important?
The crankshaft is essential for converting and managing the engine's power.
What connects to the driveshaft?
The driveshaft connects the transmission to the differential.
What is the primary role of a crankshaft?
To convert and manage the engine's power.
How does a crankshaft function?
It converts the linear motion of pistons into rotational motion to drive the vehicle.
Can a damaged crankshaft affect engine performance?
Yes, a damaged crankshaft can severely impact engine performance.
Why is the driveshaft important?
The driveshaft ensures that the power generated by the engine reaches the wheels.
Can a faulty driveshaft affect vehicle movement?
Yes, a faulty driveshaft can cause severe driving issues.
What kind of maintenance does a crankshaft require?
Crankshafts require proper lubrication and wear inspection.
Is the crankshaft involved in power transmission?
Yes, it converts power within the engine but does not transmit it to the wheels.
What is the primary role of a driveshaft?
To transmit the engine's power to the wheels.
Is the driveshaft involved in power generation?
No, it transmits power generated by the engine to the wheels.
About Author
Written by
Harlon MossHarlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Co-written by
Janet WhiteJanet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.
