Your transmission is a part of the engine that transforms power into torque. Your transmission turns all of the motion in your engine into something that gets and keeps your car moving. Without a functioning transmission, your car won't drive.
Does a new engine include a transmission?
No, the transmission is a separate unit from the engine. Either a clutch (manual transmission) or a torque converter (automatic transmission) is bolted to the flywheel, located at the rear of the engine's crankshaft. These two devices gradually apply power to the transmission.