Main Components and Functions
Torque ConverterThe torque converter transmits and multiplies torque. The torque converter is a four-element device:
^ impeller assembly
^ turbine and damper assembly
^ reactor assembly
^ clutch The standard torque converter components operate as follows:
^ Rotation of the converter housing and impeller sets 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, allowing 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 planetary gearsets through the input shaft. Bands and clutches are used to hold and drive certain combinations of gearsets. This results in five forward ratios and one reverse ratio, which are transmitted to the output shaft and differential.
Gear Ratio
1st 3.22 to 1
2nd 2.29 to 1
3rd 1.55 to 1
4th 1.00 to 1
5th 0.71 to 1
Reverse 3.07 to 1
Planetary Gearset-Overdrive
For component location, refer to Disassembled Views.
The planetary gear overdrive carrier is driven by the input shaft.
^ The overdrive planetary gearset carrier drives the center shaft via the overdrive one-way clutch in first, third, fourth, and reverse gears.
^ In second and fifth gears the overdrive sun gear is held causing the pinion gears to rotate around the overdrive sun gear.
^ The pinion gears, in turn, drive the overdrive ring gear resulting in the fifth (overdrive) gear ratio.
^ The overdrive planetary gearset is internally splined to the coast clutch for engine braking.
Planetary Gearset-Forward
For component location, refer to Disassembled Views.
The forward planetary gearset is splined to the output shaft.
^ The forward planetary gearset is driven by the forward ring gear when the forward clutch is applied.
^ The forward planetary gearset pinions drive the forward sun gear.
^ The forward sun gear is splined to the input shell.
^ The forward carrier is splined to the output shaft.
Planetary Gearset-Low/Reverse
For component location, refer to Disassembled Views.
The low/reverse planetary gearset is connected to the reverse brake drum by lugs from the low/reverse brake drum to the lugs of the low/reverse planetary gearset.
^ The low/reverse planetary gearset is driven by the forward sun gear which is splined to the input shell.
^ The forward sun gear drives the pinions in the low/reverse planetary gearset.
^ The pinions of the low/reverse planetary gearset drive the output shaft ring gear and output shaft hub which is splined to the output shaft.
^ The low/reverse planetary gearset can be held by the low one-way clutch in the low/reverse brake drum, or by the low/reverse band.
Input Shaft
For component location, refer to Disassembled Views.
^ The radial positioning of the input shaft is controlled by two bushings in the stator support.
^ Axial positioning of the input shaft is controlled by the splines in the converter turbine hub and the retaining ring in the overdrive planetary carrier.
Output Shaft
For component location, refer to Disassembled Views.
The output shaft is supported by a bearing in the case and by a bearing in the extension housing. End positioning is controlled by the parking gear and by the reverse ring gear hub and snap ring.
Apply Components
Band-Overdrive
For component location, refer to Disassembled Views.
During 2nd and 5th gear operation, hydraulic pressure is applied to the overdrive servo.
^ This pressure causes the piston to move and apply force to the band.
^ This action causes the overdrive band to hold the overdrive drum.
^ This causes the overdrive sun gear to be held stationary through the adapter plate and the overdrive drum.
Band-Low/Reverse
For component location, refer to Disassembled Views.
During second gear operation, first gear operation and reverse, hydraulic pressure is applied to the low/reverse servo.
^ This pressure causes the servo to move and apply force to the low/reverse band.
^ This action causes the low/reverse brake drum to be held.
^ This action causes the low/reverse planetary assembly to be held stationary.
Band-Intermediate
For component location, refer to Disassembled Views.
During third gear operation, hydraulic pressure is applied to the intermediate servo.
^ This pressure causes the servo to move and apply force to the intermediate band.
^ This action causes the direct clutch drum to be held.
^ The intermediate band holds the intermediate brake and direct clutch drum to the case in 3rd gear.
^ This causes the input shell and forward sun gear to be held stationary.
Clutches-Direct
For component location, refer to Disassembled Views.
The direct clutch is a multi-disc clutch made up of steel and friction plates.
^ The direct clutch is applied with hydraulic pressure and disengaged by return springs and the exhaust of the hydraulic pressure.
^ It is housed in the direct clutch drum.
^ During 4th, 5th, and reverse gear application, the direct clutch is applied transferring torque from the forward clutch cylinder to the direct clutch drum.
^ This action causes the forward sun gear to drive the pinions of the low/reverse planetary carrier.
Clutches-Forward
For component location, refer to Disassembled Views.
The forward clutch is a multi-disc clutch made up of steel and friction plates.
^ The forward clutch is applied with hydraulic pressure and disengaged by return springs and the exhaust of the hydraulic pressure.
^ The forward clutch is applied in all forward gears.
^ When applied, the forward clutch provides a direct mechanical coupling between the center shaft and the forward ring gear and hub.
Clutches-Coast
For component location, refer to Disassembled Views.
The coast clutch is a multi-disc clutch made up of steel and friction plates.
^ The coast clutch is applied with hydraulic pressure and disengaged by return springs and the exhaust of the hydraulic pressure.
^ The coast clutch is housed in the overdrive drum.
^ The coast clutch is applied when in first, third, D, and reverse positions.
^ When applied, the coast clutch locks the overdrive sun gear to the overdrive planetary carrier, thus preventing the one-way clutch from overrunning when the vehicle is coasting.
^ This allows the use of engine compression to help slow the vehicle and provide engine braking.
One-Way Clutch-Direct
For component location, refer to Disassembled Views.
The direct one-way clutch is a spray-type one-way clutch that is pressed into the center shaft.
^ The direct one-way clutch is driven by the ring gear of the overdrive planetary carrier.
^ The direct one-way clutch holds and drives the outer splines of the center shaft in first, third, fourth and reverse gears.
^ The direct one-way clutch overruns during all coast operations and at all times in 2nd and fifth gear.
One-Way Clutch-Low/Reverse
For component location, refer to Disassembled Views.
The low/reverse one-way clutch is a spray-type one-way clutch.
^ The low/reverse one-way clutch holds the low/reverse drum and low/reverse planetary assembly to the case in first and second gear.
^ In all other gears the low/reverse one-way clutch overruns.
Hydraulic System
Fluid Pump
For component location, refer to Disassembled Views.
^ The fluid pump provides the fluid pressure necessary to charge the torque converter, main control assembly, transmission cooling system, lubrication system and apply devices.
^ The fluid pump is a positive displacement, gear type pump.
^ The fluid pump is driven by the torque converter impeller hub.
Filter
For component location, refer to Disassembled Views.
^ All fluid drawn from the transmission fluid pan by the fluid pump passes through the fluid filter.
^ The transmission fluid filter and its accompanying seals are part of the fluid path from the sump (pan) to the fluid pump.
^ The transmission fluid filter has a bypass section which allows fluid vented at the main regulator valve to be recirculated to the fluid pump, without passing through the transmission fluid filter.
Main Control
For component location, refer to Disassembled Views.
^ The main control assembly and related components are part of the pressure side of the hydraulic system.
^ The main control assembly consists of the solenoids, the valve body assembly and the separator plate.
^ These components combine to convert electrical signals into hydraulic actions.
^ All valves in the main control assembly are anodized aluminum and cannot be sanded, filed, or dressed in any other way. If there is any damage to the valves that prevents or restricts their movement, install a new main control assembly.