Manual Transmission/Transaxle: Description and Operation

The transmission consists of the following:
^ A two part die cast aluminum housing
^ Bevel cut gears that rotate on needle roller bearings
^ An input shaft and output shaft that rotate on ball bearings
^ A layshaft that rotates on roller bearings
^ Selector shaft assemblies

The engine rotational torque is transmitted from the crankshaft through the clutch to the transmission input shaft, which then transmits drive to a layshaft and then the output shaft by utilizing an arrangement of gears. When reverse gear is selected, the direction of the output shaft is changed by an idler gear assembly. In neutral, none of the gears are connected to the input or output shaft through the relevant synchronizer unit. No torque is transmitted to the driveline.

The clutch system consists of the following components:
^ a flywheel
^ a clutch disc
^ a clutch pressure plate
^ a clutch master cylinder
^ a clutch slave cylinder
^ a clutch release hub and bearing

The clutch master cylinder transmits fluid pressure to the slave cylinder, which in turn moves the clutch release hub and bearing. The clutch master cylinder uses brake fluid and shares a common reservoir with the brake master cylinder.

The clutch is a single plate, dry-friction disc with a diaphragm-style spring clutch pressure plate. The clutch disc has a hub which is splined to the input shaft. The clutch disc has friction material where it contacts the flywheel and the pressure plate. The clutch pressure plate applies pressure to the clutch disc, holding it tightly against the surface of the flywheel.

In the engaged position, the diaphragm spring holds the clutch pressure plate against the clutch disc so that engine torque is transmitted to the input shaft. When the clutch pedal is depressed, the clutch release hub and bearing pushes the diaphragm spring center toward the flywheel. The diaphragm spring pivots at the fulcrum, relieving the load on the clutch pressure plate. Steel spring straps riveted to the clutch pressure plate cover pull the clutch pressure plate from the clutch disc, disengaging the engine torque from the transmission and enabling the gears to be changed.