ClutchConnects the engine to the transmission. Disconnects it while the gears are changed. An automatic has a torque converter here instead.
Transmission (gearbox)Changes the gear ratio and gives reverse. The engine can then run at a good speed whatever the car's speed.
Slip jointA splined joint for the driveshaft. Lets it get a little longer or shorter as the rear axle moves up and down.
Universal jointsLet the driveshaft keep turning while it runs at an angle. One joint at each end.
Driveshaft (propeller shaft)The long shaft from the transmission back to the rear axle. It carries the power.
Differential (final drive)Lets the two wheels turn at different speeds in a turn. The final drive, it also turns the drive through a right angle to the axles.
Axle shaftsRun from the differential out to the driving wheels. They sit inside the rear axle.
Drive wheelsThe wheels the drivetrain turns: here the rear wheels. The front wheels only steer.
How this list was compiled: Read 2026-09-27. (1) US Army, TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 19-1 (the power train's clutches, transmissions, transfer cases, propeller shafts, universal joints, final drives, differentials and live axles) and chapter 28 (the propeller or drive shaft, its slip joint or sliding yoke, universal joints), https://archive.org/details/tm-9-8000-principles-of-automotive-vehicles-1985 . (2) Wikipedia, Drivetrain, https://en.wikipedia.org/wiki/Drivetrain : the drivetrain delivers power to the drive wheels and excludes the engine; a manual car's clutch, gearbox, propeller shaft, rear axle, final drive and differential; the powertrain includes the engine. Drive shaft, https://en.wikipedia.org/wiki/Drive_shaft : a prop-shaft assembly: propeller shaft, slip joint and at least one universal joint. Licence: own work
The drawing: Drawn for this site by script, 2026-09-27. Own work, nothing traced. Licence: own work
How it works
These are the parts of a car's drivetrain, everything that carries the engine's power to the wheels, on a rear-wheel-drive car seen from above with the front at the top.
Read the full guide
From engine to axle
The clutch joins the engine to the transmission, which picks the gear. The slip joint and a universal joint link the transmission to the driveshaft, which runs back to a second universal joint at the rear axle.
Out to the wheels
The differential, the final drive, turns the power through a right angle and splits it between the two axle shafts, letting the drive wheels turn at different speeds in a corner.
The engine is drawn but not numbered: the drivetrain is everything after it. Engine and drivetrain together are the powertrain.
Questions and answers
Is the engine part of the drivetrain?
No. The drivetrain is the parts that carry the engine's power to the wheels. The engine and the drivetrain together make up the powertrain.
What does a universal joint do?
It lets the driveshaft keep turning while it runs at an angle to the transmission and the axle, which move relative to each other.
How is a front-wheel-drive drivetrain different?
There is no long driveshaft: the gearbox, final drive and differential sit together at the front, with short drive shafts and constant-velocity joints at each front wheel.