Main Components and Functions
Main Components and FunctionsPart 1 Of 2:
Part 2 Of 2:
Automatic Transmission-Sectional View
Torque Converter
The torque converter transmits and multiplies torque. The torque converter is a four-element device:
^ Impeller assembly
^ Turbine assembly
^ Reactor assembly
^ Clutch and damper assembly
The standard torque converter components operate as follows:
^ Rotation of the converter housing and impeller set the fluid in motion.
^ The turbine reacts to the fluid motion from the impeller, transferring rotation to the geartrain through the input shaft.
^ The reactor redirects fluid going back into the impeller, providing for torque multiplication.
^ The clutch and damper assembly dampens powertrain torsional vibration and provides a direct mechanical connection for improved efficiency.
^ Power is transmitted from the torque converter to the planetary gearsets and other components through the input shaft,
Geartrain
Power is transmitted from the torque converter to the geartrain components through the input shaft and forward clutch cylinder.
^ By holding or driving certain members of the gearset, four forward ratios and one reverse ratio are obtained and transmitted to the output shaft. The ratios are as follows:
Input Shaft
The input shaft is supported by two bushings in the stator support. End positioning of the input shaft is controlled by the splines in the converter turbine and the overdrive planet assembly.
Output Shaft
The output shaft is supported by two bushings in the case and by the slip-yoke and bushing in the extension housing. End positioning is controlled by the parking pawl gear and snap ring or shoulder and by the reverse ring gear hub and snap ring.
Overdrive System
The overdrive planetary system consists of the overdrive planet assembly, overdrive sun gear, overdrive ring gear, coast clutch cylinder, overdrive one-way clutch assembly and the center shaft. The overdrive planet assembly is splined to the input shaft. The overdrive sun gear is centered by a bushing on the input shaft and held in place laterally by needle bearings on the reactor support and the overdrive planet assembly. The overdrive sun gear is splined to the coast clutch cylinder, which in turn is splined to the overdrive one-way clutch inner race.
The outer race of the one-way clutch is splined to the overdrive ring gear, which is splined to the center shaft. The center shaft is centered by the forward planetary assembly and is laterally held by needle bearings on the center support and the overdrive planet assembly. The center shaft is splined into the forward clutch cylinder.
The coast clutch is splined between the coast clutch cylinder and the overdrive ring gear. The coast clutch is activated to carry out engine braking in MANUAL 1, MANUAL 2 and third gear with the transmission control switch engaged.
The overdrive clutch steel plates are splined to the case, the friction plates are splined to the coast clutch cylinder. The overdrive clutch holds the coast clutch cylinder and, in turn, the overdrive sun gear, to permit the planet assembly to overdrive the ring gear.
Part 1 Of 2:
Part 2 Of 2:
Center Support and Intermediate/Overdrive Clutch Cylinder
The center support provides a pilot for the forward clutch and direct clutch cylinders. It also provides fluid for clutch application and lube flow. The center support is held radially and laterally by the case. Fluid supply enters through feed bolts into the center support and supplies the forward clutch and the intermediate lube circuits. The direct clutch is fed by the center support.
The intermediate/overdrive clutch cylinder is radially supported by the case. Laterally, the cylinder is held in the case by a snap ring. The overdrive circuit is fed through a feed bolt into the cylinder. The intermediate clutch circuit is fed through nearby orifices.
Part 1 Of 3:
Part 2 Of 3:
Part 3 Of 3:
Forward Drive System
The forward drive system consists of the forward clutch cylinder, intermediate brake drum, intermediate one-way clutch, input shell, forward ring gear, forward ring gear hub, forward/reverse sun gear and the forward planetary carrier and forward planetary gears.
The forward clutch cylinder is splined on the center shaft. The forward ring gear is piloted on the forward ring gear hub. Thrust bearings on the forward planet assembly and forward clutch cylinder hold the forward ring gear hub in place.
The intermediate brake drum is radially supported by bushings on the center support and is laterally controlled by a thrust washer on the forward clutch cylinder and center support. The intermediate brake drum has the inner race of the intermediate one-way clutch press-fitted on its pilot. The intermediate one-way clutch's outer race is splined to the intermediate friction clutch, which is splined to the case. The intermediate brake drum has lugs that are slotted into the input shell to form a mechanical connection. The input shell is splined into the forward/reverse sun gear. The forward/reverse sun gear is common to two planetary gearsets. The forward planet is splined to the output shaft and is laterally positioned by needle bearings on the sun gear and on the forward clutch cylinder.
Two friction clutch assemblies, the direct clutch and the forward clutch, are shown with the forward planetary assembly. The direct clutch assembly splines the forward clutch cylinder to the intermediate brake drum. The forward clutch assembly splines the forward clutch cylinder to the forward ring gear. The forward clutch is activated during all forward gears. While in third or fourth gear, both the direct and forward clutches are applied to hold the forward planetary assembly and enable it to act as a solid shaft.
In second gear, the intermediate clutch assembly holds the forward/reverse sun gears. It is applied, along with the intermediate one-way clutch, to hold the intermediate brake drum, input shell and forward/reverse sun gear. In higher gears, the one-way clutch overruns.
Low and Reverse Drive System
The reverse planetary assembly consists of the reverse planetary carrier, reverse planet gears, the reverse ring gear, the reverse ring gear hub, the reverse clutch hub and the low-reverse one-way clutch assembly.
The reverse ring gear hub is splined to the output shaft and to the reverse ring gear. The reverse ring gear hub is laterally held by a needle bearing on the inner race of the low-reverse one-way clutch and a snap ring on the output shaft. The reverse planet assembly is splined to the low-reverse clutch hub. The low-reverse clutch hub is connected by the reverse clutch to the case. The inner race of the one-way clutch is bolted to the case.
Part 1 Of 2:
Part 2 Of 2:
The reverse clutch assembly is activated in REVERSE gear and in MANUAL 1. The reverse clutch bypasses the reverse one-way clutch during coast and MANUAL 1. The reverse clutch holds the reverse planet assembly in REVERSE gear to enable the sun gear to drive the reverse ring gear in the opposite direction.
Apply Components
The following information describes the operation of the three one-way clutches.
One-Way Clutch-Overdrive
The overdrive one-way clutch transmits engine torque from the overdrive sun gear to the overdrive ring gear in first, second and third gear range.
The overdrive one-way clutch transmits power when the sprays are engaged between the inner and outer races. The inner race is splined to the coast clutch cylinder, which in turn is splined to the overdrive sun gear. The outer race is splined to the overdrive ring gear.
The overdrive one-way clutch engages whenever the overdrive planetary system attempts to drive the overdrive sun gear clockwise when the overdrive ring gear has a counterclockwise torque from the vehicle. When tightened counterclockwise, the overdrive one-way clutch engages and acts as a wedge to lock the sun gear and the ring gear together. During coast, the overdrive one-way clutch enables the ring gear to overrun or spin at a faster rate than the sun gear.
The overdrive one-way clutch overruns when in overdrive (fourth gear). In overdrive? the coast clutch cylinder is held by the overdrive one-way clutch, which in turn holds the overdrive sun gear. This causes the overdrive planet assembly to walk around the sun gear and overdrive the overdrive ring gear. The inner race of the overdrive one-way clutch is thus held stationary while the outer race is allowed to overrun clockwise.
One-Way Clutch Intermediate
The intermediate one-way clutch holds the forward/reverse sun gear stationary relative to the case in second gear. The outer race of the intermediate one-way clutch is splined to the intermediate clutch, which in turn is splined to the case. The inner race is part of the intermediate brake drum, which is connected to the sun shell. The sun shell is splined to the forward/reverse sun gear.
In second gear, the intermediate clutch holds the outer race of the intermediate one-way clutch. Torque from the vehicle acts counterclockwise on the output shaft, and in turn on the forward planetary carrier and the reverse ring gear. Torque from the center shaft is counterclockwise.
This combination applies a counterclockwise torque on the sun gear and likewise the intermediate one-way clutch. The intermediate one-way clutch engages, causing the forward ring gear to turn the forward planetary carrier clockwise at reduced speed. During coast, the intermediate one-way clutch allows the sun gear to spin clockwise as the engine rpm coasts down.
The intermediate one-way clutch overruns in third, fourth and REVERSE gears. The direct clutch is engaged, causing the intermediate brake drum to rotate clockwise with the center shaft. With the intermediate drum rotating clockwise, the inner race also rotates clockwise, causing the intermediate one-way clutch to overrun.
In first gear, the outer race of the intermediate one-way clutch is not held, and the intermediate one-way clutch is overrunning.
One-Way Clutch, Intermediate (Spray Design)
One-Way Clutch Low-Reverse
The low-reverse one-way clutch holds the reverse planetary carrier stationary to the case in first gear. The inner race of the low-reverse one-way clutch is bolted directly to the case. The outer race is splined to the reverse clutch hub, which is splined to the reverse planetary carrier.
In first gear, the center shaft drives the forward ring gear clockwise by way of the forward clutch. With the forward planetary carrier providing a counterclockwise resisting torque, the forward/reverse sun gear is driven counterclockwise.
As the sun gear is turned counterclockwise and the reverse ring gear is turned counterclockwise by the resistance of the vehicle, the reverse planetary carrier is also turned counterclockwise. Because the reverse planetary carrier is prevented from turning counterclockwise by the low-reverse one-way clutch, the torque is transferred from the sun gear to the reverse ring gear and the output shaft. During coast, the planetary carrier is allowed to overrun and spin clockwise.
The low-reverse one-way clutch overruns in second. third and fourth gears. In these cases the forward/reverse sun gear is stationary while the reverse ring gear turns clockwise with the output shaft. This turns the reverse planetary carrier clockwise. causing the low-reverse one-way clutch to run clockwise and overrun.