SPECIFICATIONS

Material

^a 6F50 transmission.
^b 6F55 transmission.

Torque Specifications

^a Refer to the procedure in this section.

General Specifications

Solenoid Operation Chart

^a Turns on above 8 km/h (5 mph).
^b Turns off above 8 km/h (5 mph).

NC = Normally closed

NH = Normally high

NL = Normally low

Pressure Chart

Clutch Application Chart

H = Holding

D = Driven

Stall Speed Chart

Gear Ratio Chart

Shift Speeds

Differential and Transfer Gear Bearing Preload Shim Selection Chart

DESCRIPTION AND OPERATION

Automatic Transmission

Component Location

1. Solenoid body
2. Valve body
3. Forward clutch (clutch brake 1,2,3,4)
4. Low OWC
5. Low/reverse clutch (clutch brake L/R)
6. Intermediate clutch (clutch brake 2,6)
7. Direct clutch (drive clutch 3,5,R)
8. Overdrive clutch (drive clutch 4,5,6)
9. Front planetary assembly
10. Center planetary assembly
11. Rear planetary assembly
12. Differential transfer drive gear
13. Differential transfer driven gear
14. Transfer shaft roller bearing and cup
15. Differential drive pinion gear
16. Park gear
17. Differential ring gear
18. Fluid filter
19. Differential roller bearing and cup
20. Differential carrier gear and case assembly
21. Differential lube tube
22. Torque converter
23. TCC
24. Torque converter cover
25. Support assembly (converter reactor)
26. Turbine/input shaft
27. Chain and sprocket pump driver
28. Reactor
29. Turbine
30. Impeller

Overview

This automatic transmission is a 6-speed transmission with electronic shift control. It is designed for operation in a transverse powertrain for FWD and AWD vehicles.

This transmission has the following features:

• Six forward speeds
• Torque converter with an integral converter clutch
• Electronic shift and pressure controls
• Three planetary gearsets
• Three fixed multi-disc clutches
• Two multi-plate drive clutches

All hydraulic functions are directed by electronic solenoids to control the following:

• Engagement feel
• Shift feel
• Shift scheduling
• Modulated TCC applications

This transmission has a main control which contains:

• Solenoid body with TFT sensor
• Upper Valve body
• Lower Valve body

This automatic transmission is an electronically controlled transmission. Gear selection is achieved by the control of transmission fluid flow to operate various internal clutches. The PCM operates the electrical components and provides control of gear selection shift pressure, which increases refinement and torque converter slip.

In the event of a system fault, the PCM also provides for Failure Mode Effect Management to maintain maximum functional operation of the transmission with a minimum power reduction. In the event of a total loss of control or electrical power, the basic transmission functions P, R, N and D are retained. Also 5th gear is retained by the hydraulic system.

Identification Tags

Identification Tag Location

1. Transmission identification tag
2. Solenoid body identification tag

Transmission Identification Tag

1. Transmission part number
2. Transmission build date
3. Transmission serial number

Original Solenoid Body Tag

1. 13 - digit solenoid body strategy
2. 7 - digit solenoid body identification

Replacement Solenoid Body Tag

1. 13 - digit solenoid body strategy
2. 7 - digit solenoid body identification

Solenoid Body Identification Tag

1. 13 - digit solenoid body strategy
2. 7 - digit solenoid body identification

System Operation

Park

 Park Clutch Application Chart

H = Holding

 Park Position Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• With the selector lever in PARK, the low/reverse clutch holds the rear planetary carrier/center ring gear stationary.
• The park pawl holds the rear ring/front planetary carrier stationary.
• The turbine shaft drives the center sun gear.

Reverse

 Reverse Clutch Application Chart

H = Holding

D = Driving

 Reverse Position Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• With the selector lever in REVERSE, the low/reverse clutch holds the rear planetary carrier/center ring gear stationary.
• The direct clutch drives the rear sun gear.
• The rear ring/front planetary carrier transfers torque to the output hub in a reverse direction with a ratio of 2.88.

Neutral

 Neutral Clutch Application Chart

H = Holding

 Neutral Position Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• With the selector lever in NEUTRAL, the low/reverse clutch holds the rear planetary carrier/center ring gear stationary.
• The turbine shaft drives the center sun gear.

1st Gear

NOTE: The transmission operates differently in 1st gear above and below 8 kmh (5 mph). Transmission operation is the same below 8 kmh (5 mph) and in the LOW position.

1st Gear Above 8 kmh (5 mph) Clutch Application Chart

H = Holding

1st Gear LOW Position and Below 8 kmh (5 mph) Clutch Application Chart

H = Holding

1st Gear Above 8 kmh (5 mph) Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

1st Gear LOW Position and Below 8 kmh (5 mph) Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• In first gear, the forward clutch holds the front sun gear stationary.
• The rear planetary carrier/center ring gear is held stationary by the low OWC and/or the low reverse (1, R) clutch.
• The turbine shaft transfers torque to the center sun gear. The center sun gear transfers the torque to the center planetary carrier/front ring gear. The front ring gear transfers torque to the front planetary carrier/rear ring gear and the output hub to produce a ratio of 4.48.

2nd Gear

 2nd Gear Clutch Application Chart

H = Holding

 2nd Gear Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• In second gear the forward clutch holds the front sun gear stationary.
• The intermediate clutch holds the rear sun gear stationary.
• The turbine shaft transfers torque to the center sun gear. The center sun gear transfers torque to the center ring gear/rear planetary carrier.
• The rear planetary carrier transfers the torque to the rear ring gear/front planetary carrier and the output hub to produce a gear ratio of 2.87.

3rd Gear

 3rd Gear Clutch Application Chart

H = Holding

D = Driving

 3rd Gear Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• In third gear the forward clutch holds the front sun gear stationary.
• The direct clutch drives the rear sun gear.
• Power flows from the center sun gear to the center planetary carrier/front ring gear. From there, torque is transferred to the rear ring gear/front planetary carrier.
• Power also flows from the rear sun gear to the rear ring gear/front planetary carrier.
• The two inputs to the front planetary carrier combine and transfer torque to the output hub to produce a gear ratio of 1.84.

4th Gear

 4th Gear Clutch Application Chart

H = Holding

D = Driving

 4th Gear Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• In fourth gear the forward clutch holds the front sun gear stationary.
• The overdrive clutch drives the rear planetary carrier/center ring gear.
• Power flows from turbine shaft to the center sun gear and center ring gear.
• The two inputs to the center planetary carrier combine and transfer torque to the front ring gear.
• The front ring gear transfers the torque to the front planetary carrier and onto the output hub to produce a gear ratio of 1.41.

5th Gear

 5th Gear Clutch Application Chart

D = Driving

 5th Gear Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• In fifth gear the overdrive clutch drives the rear planetary carrier/center ring gear.
• The direct clutch drives the rear sun gear.
• The turbine shaft transfers torque to the center sun gear, rear sun gear, and rear planetary carrier/center ring gear.
• The torque from the three inputs locks the three planetary gearsets which produces a gear ratio of 1 to 1

Fail-safe Mode
• Because both SSD and SSB apply the clutches they control when they are turned OFF, 5th gear is the fail-safe.

6th Gear

 6th Gear Clutch Application Chart

H = Holding

D = Driving

 6th Gear Solenoid Operation Chart

NC = Normally Closed

NH = Normally High

NL = Normally Low

Powerflow
• In sixth gear the overdrive clutch drives the rear planetary carrier/center ring gear.
• The intermediate clutch holds the rear sun gear.
• The torque from the rear planetary carrier is transferred to the rear ring gear/front planetary carrier and the output hub which produces a gear ratio of 0.74.

Electrical System

Component Location

The solenoid body contains 5 shift solenoids, 1 TCC solenoid and 1 LPC solenoid.

Solenoid Body

1. SSE
2. SSD
3. SSA
4. TCC
5. SSB
6. SSC
7. LPC

System Operation

The PCM and its input/output network controls the following operations:

• Shift timing
• Line pressure (shift feel)

The transmission control strategy is separate from the engine control strategy in the PCM, although some of the input signals are shared. When determining the best operating strategy for transmission operation, the PCM uses input information from engine and driver related sensors and switches.

In addition, the PCM receives input signals from transmission related sensors and switches. The PCM uses these signals when determining transmission operating strategy.

Using all of these input signals, the PCM can determine when the time and conditions are right for a shift or when to apply or release the TCC. It also determines the best line pressure to optimize shift engagement feel. To accomplish this, the PCM uses output solenoids to control transmission operation.

Active Transmission Pursuit Mode (ATPM)

ATPM is a feature within the transmission software that enables the transmission to be more aggressive with shifting during aggressive driving (e.g. pursuit). Police vehicles have ATPM software that uses accelerator pedal, brake pedal, and steering position input to alter the shift scheduling for pursuit purposes.

The transmission software changes how the transmission shifts when it senses the vehicle is being driven aggressively and switches it back to save fuel when the aggressive driving is completed.

The software logic is made up of 2 parts:

• Brake torque-induced logic to handle downshifts under braking
• Upshift inhibit logic to hold gears around the corners; during corner exit, the transmission has not upshifted so there is no delay from the transmission downshifting out of a corner

Brake Torque Logic
• Uses brake line pressure and decleration rates as inputs and knows if the vehicle is performing an aggressive braking maneuver.
• If a set threshold is passed, the transmission software downshifts to the next possible gear during the braking event.
• The brake pressure threshold cannot be passed during normal driving maneuvers.

Upshift Inhibit Logic
• Uses lateral acceleration (cornering) to inhibit upshifts.
• When the lateral acceleration threshold is crossed (when the vehicle turns hard enough), the vehicle holds gears and upshifts only at redline.
• Stays active for 30 seconds after pursuit driving is completed, or deactivates when there is three continuous seconds of closed throttle.

Network Message Chart

 Communication Message Chart

Component Description

Sensors and Switches

The PCM controls the electronic functions of this transmission. The PCM receives input signals from engine and transmission sensors and uses these inputs to control line pressure, shift time, TCC and shift solenoids.

Solenoid Body

The solenoid body contains 7 solenoids: 5 shift solenoids ( SSA , SSB , SSC , SSD and SSE ), 1 TCC solenoid and 1 LPC solenoid. The TFT sensor is located in the solenoid body. The solenoid body is serviced as an assembly.

The solenoid body has a unique strategy data file that must be downloaded to the PCM. There is a 7-digit solenoid body identification and a 13-digit solenoid body strategy for each solenoid body. When a new solenoid body or transmission is installed, the scan tool must be used to get the solenoid body strategy data file and download it into the PCM.

If the PCM is replaced and the PCM data cannot be inhaled or exhaled, the solenoid body identification and solenoid body strategy must be downloaded into the PCM.

This transmission uses 3 types of solenoids: On/Off, normally low and normally high. On/Off solenoids open or close hydraulic passages based on the voltage signal it receives. Normally low solenoids provide hydraulic pressure proportional to supplied current. A normally low solenoid will not provide pressure without current, while it will supply high pressure with high current. Normally high solenoids provide pressure inversely proportional to supplied current. Normally high solenoids provide full output of pressure with no current and very low pressure with high current.

ON/OFF Solenoids

Normally Low Solenoids

Normally High Solenoids

Hydraulic System

Component Location

1. Transmission fluid filter assembly
2. Pump assembly
3. Chain and sprocket assembly
4. Stator support assembly
5. Transmission case
6. Torque converter housing
7. Main control cover assembly
8. Solenoid body
9. Main control valve body

System Diagram

 Printable / zoomable view of this graphic

Component Description

Transmission Pump and Fluid Filter

The transmission fluid in the sump area at the bottom of the transmission case flows through a transmission fluid filter to the pump assembly. The pump is bolted to the torque converter housing and is chain driven from a sprocket that is mounted on the stator support and turned by the torque converter.

1. Transmission fluid filter assembly
2. Pump assembly
3. Chain and sprocket assembly
4. Stator support assembly
5. Transmission case
6. Torque converter housing

Transmission Fluid Level

The transmission fluid level is checked with the transmission at normal operating temperature between 82.3ºC (180ºF) and 93.4ºC (200ºF). The transmission fluid level indicator is part of the filler cap. The correct transmission fluid level is between the MIN and MAX in the cross hatches of the transmission fluid level indicator.

1. Transmission fluid level indicator
2. Main control cover assembly
3. Correct transmission fluid level at normal operating temperature
4. Low transmission fluid level at normal operating temperature
5. High transmission fluid level at normal operating temperature

Main Control

The hydraulic system has a main control assembly. The main control assembly consists of a valve body and a solenoid body. The valve body contains the hydraulic regulator and multiplex shift valves. The solenoid body contains the shift solenoids that control the hydraulic valves. The solenoid body is serviced as an assembly and can not be disassembled. The solenoid body is controlled by the PCM. The PCM has software stored in it specific to the solenoid body currently in the transmission, called the solenoid body strategy. A new solenoid body strategy must be downloaded into the PCM any time a new solenoid body is installed.

1. Main control cover assembly
2. Solenoid body
3. Main control valve body
4. Transmission case

1. Bolts -M6 x 63
2. Bolts - M6 x 35
3. Cover - transfer plate
4. Case-to-valve body transfer plate
5. Separator plate - valve body-to-transfer plate
6. Main control valve body
7. Separator plate - main control valve body-to-lower valve body
8. Lower valve body assembly
9. Check balls
10. Low/reverse and overdrive clutch regulator valve assembly
11. Torque converter clutch regulator apply valve assembly
12. Intermediate clutch regulator valve assembly
13. Direct clutch regulator valve assembly
14. Pressure regulator valve assembly
15. Isolator valve assembly
16. Torque converter clutch control valve assembly
17. Multiplex manual valve
18. Multiplex shift valve
19. Manual valve
20. Direct clutch boost valve assembly
21. Solenoid regulator valve assembly
22. Low/reverse and overdrive clutch boost valve assembly
23. Forward clutch boost valve assembly
24. Forward clutch regulator valve assembly

1. Solenoid body
2. Solenoid body filter
3. Seal - solenoid body electrical connector
4. Leadframe area

Multi-Plate Clutch

Multi-plate clutches are clutches that consist of multiple friction and steel clutch discs that when pressure is applied, either drive or hold (brake) components of the planetary gearset. This transmission has 5 multi-plate clutches:

• Forward (1, 2, 3, 4)
• Direct (3, 5, R)
• Intermediate (2, 6)
• Overdrive (4, 5, 6)
• Low/reverse

Both the direct (3, 5, R) and the overdrive (4, 5, 6) clutches are drive clutches. The direct (3, 5, R) clutch drives the rear planetary sun gear and the overdrive (4,5,6) clutch drives the rear planetary carrier. The forward (1, 2 ,3, 4), intermediate (2, 6) and the low/reverse clutches are brake clutches. The forward (1, 2, 3, 4) clutch holds the front sun gear, the intermediate (2, 6) clutch holds the rear sun gear and the low/reverse clutch holds the rear planetary carrier.

Clutches; overdrive (4, 5, 6) and direct (3, 5, R) are balanced in terms of dynamic pressure. That is, their pistons are exposed to the transmission fluid flow on both sides to prevent pressure buildup in the clutch as speed increases. This dynamic pressure equalization process is achieved by a baffle plate and pressure-free transmission fluid supply by a lubricating passage, through which the space between the piston and baffle plate is filled with transmission fluid.

The advantages of this dynamic pressure equalization are:

• reliable clutch engagement and release in all speed ranges.
• improved shift refinement.

External Sealing

The torque converter housing has a lip-type seal that seals the torque converter hub. The manual control lever shaft and half shafts also use lip-type seals. AWD vehicles do not use a RH half shaft seal, the transmission is sealed by the PTU on the RH side.

The torque converter housing is sealed to the transmission case with silicone sealant.

The transmission cover is sealed to the transmission case with a reusable gasket. The main control cover is sealed to the transmission case and the solenoid body with reusable rubber gaskets.

The TSS sensor is sealed to the transmission cover with an O-ring seal. The transmission fluid filler tube is sealed to the main control cover with an O-ring seal that is serviced with the transmission fluid filler tube. The transmission fluid level indicator is sealed to the transmission fluid filler tube with an O-ring seal that is serviced with the transmission fluid level indicator.

The line pressure tap plug, transmission fluid drain plug and the lubrication circuit tap plug have pipe threads and seal when tightened to specification.

1. Torque converter hub seal
2. Torque converter
3. RH halfshaft seal ( FWD only)
4. Torque converter housing
5. LH halfshaft seal
6. Transmission case
7. Main control cover-to-solenoid body seal
8. Main control cover gasket
9. Solenoid body assembly
10. Main control cover
11. Transmission fluid level indicator
12. Transmission fluid level indicator
13. Transmission case-to-transmission cover gasket
14. Transmission cover
15. TSS sensor
16. TSS sensor bolt
17. Line pressure tap plug
18. Transmission fluid drain plug
19. Lubrication circuit tap plug

Hydraulic Circuits Legend

Line Pressure Hydraulic Circuits

The PCM controls line pressure with the LPC solenoid. This affects shift feel and apply component operation.

When the engine is running, the pump supplies pressure to the pressure regulator valve, which is controlled by the LPC solenoid. The pressure regulator valve controls the line pressure.

The line pressure circuit supplies the manual valve. The manual valve directs the line pressure to either the REV/REV SUPPLY circuit when the manual control lever is in the REVERSE position or the DRIVE 1 circuit when the manual control lever is in the DRIVE or LOW position.

Lubrication Hydraulic Circuits

Lubrication for the transmission is supplied by the transmission fluid cooler return tube. Transmission fluid is sent to the transmission fluid cooler from the TCC control valve.

LINE pressure supplied to the pressure regulator valve is sent to the TCC control valve as CONV FD pressure. During TCC release, the TCC control valve sends the transmission fluid to the torque converter to release the clutch. The transmission fluid returns to the TCC control valve from the torque converter and is directed to the transmission fluid cooler on the COOLER FEED circuit.

Torque Converter Hydraulic Circuits

The PCM controls the TCC solenoid. The TCC solenoid applies hydraulic pressure to the TCC control and regulator apply valves through the TCC SOL SIG circuit. Regulated DRIVE 2 pressure from the multiplex shift valve is directed to the TCC control valve by the TCC regulator apply valve through the REG APPLY circuit. The TCC control valve directs pressure from the REG APPLY circuit to the TCC APPLY circuit to apply the clutch.

The transmission fluid returns to the TCC control valve through the TCC RELEASE hydraulic circuit. The TCC control valve opens the TCC RELEASE circuit to exhaust, so the TCC RELEASE circuit is not pressurized when the TCC is applied.

When the TCC is released, The TCC solenoid does not apply hydraulic pressure to the TCC control or regulator apply valves. The TCC control valve, in this position, directs hydraulic pressure from the CONV FD circuit to the torque converter through the TCC RELEASE hydraulic circuit and it returns to the TCC control valve through the TCC APPLY circuit.

Solenoid Hydraulic Circuits

LINE pressure from the pump is directed to the individual shift, TCC and LPC solenoids by the solenoid regulator valve on the SOL FEED circuit. The solenoids, controlled by the PCM, direct the fluid to the valves that they control.

The LPC solenoid sends varying pressure to the line pressure regulator valve to control line pressure.

Forward Clutch Hydraulic Circuits

When the forward (1, 2, 3, 4) clutch is applied in 1st (above 8 kmh (5 mph), 2nd, 3rd and 4th gears, LINE pressure from the pump is directed to the multiplex shift valve by the manual valve through the DRIVE 1 hydraulic circuit. The multiplex shift valve supplies the forward (1, 2, 3, 4) clutch regulator valve with pressure through the DRIVE 2, CB26FD/CB1234FD and CB1234 SUP hydraulic circuits. The forward (1, 2, 3, 4) clutch regulator valve directs regulated pressure to the forward (1, 2, 3, 4) clutch through the CB1234 hydraulic circuit

When the forward (1, 2, 3, 4) clutch is applied in LOW position and 1st gear below 8 kmh (5 mph), LINE pressure from the pump is directed to the multiplex shift valve by the manual valve through the DRIVE 1 hydraulic circuit. The multiplex shift valve directs the pressure to the multiplex manual valve through the REV DRIVE B circuit. The multiplex manual valve directs the REV DRIVE B pressure to the forward (1, 2, 3, 4) clutch regulator valve through the DRIVE B, CB26FD/CB1234FD and CB1234 SUP circuits. SSA supplies varying solenoid pressure to the CB1234 clutch regulator and boost valves. As the CB1234 clutch regulator valve moves, it supplies the forward (1, 2, 3, 4) clutch and CB1234 boost valve with regulated line pressure through the CB1234 circuit. The CB1234 boost valve directs the regulated line pressure to the opposite side of the regulator valve through the CB1234 FDBK circuit for controlled forward (1, 2, 3, 4) clutch engagement.

Direct (3, 5, R) Clutch Hydraulic Circuits

When the direct (3, 5, R) clutch is applied in REVERSE, LINE pressure from the pump is directed to the multiplex manual valve by the manual valve through the REV hydraulic circuit. The multiplex manual valve supplies the direct (3, 5, R) clutch regulator valve with pressure through the REV SUPPLY and C35R SUPPLY hydraulic circuits. To apply the direct (3, 5, R) clutch, SSB applies varying solenoid pressure to the C35R clutch regulator and boost valves. As the C35R regulator valve moves, it supplies the direct (3, 5, R) clutch and C35R boost valve with regulated line pressure through the C35R circuit. The C35R boost valve directs the regulated line pressure to the opposite side of the C35R clutch regulator valve through the C35R FDBK circuit for controlled direct (3, 5, R) clutch engagement.

When the direct (3, 5, R) clutch is applied in 3rd and 5th gears, LINE pressure from the pump is directed to the multiplex shift valve by the manual valve through the DRIVE 1 hydraulic circuit. The multiplex shift valve directs the pressure to the direct (3, 5, R) clutch regulator valve through the DRIVE 2/C35R SUPPLY circuits. To apply the direct (3, 5, R) clutch, SSB applies varying solenoid pressure to the C35R clutch regulator and boost valves. As the C35R regulator valve moves, it supplies the direct (3, 5, R) clutch and C35R boost valve with regulated line pressure through the C35R circuit. The C35R boost valve directs the regulated line pressure to the opposite side of the C35R clutch regulator valve through the C35R FDBK circuit for gradual direct (3, 5, R) clutch engagement.

Intermediate (2, 6) Clutch Hydraulic Circuits

When the intermediate (2, 6) clutch is applied in 2nd and 6th gears, LINE pressure from the pump is directed to the multiplex shift valve by the manual valve through the DRIVE 1 hydraulic circuit. The multiplex shift valve supplies the intermediate (2, 6) clutch regulator valve with pressure through the DRIVE 2 and CB26FD/CB1234FD hydraulic circuits. The intermediate (2, 6) clutch regulator valve is controlled by SSC and directs regulated pressure to the intermediate (2, 6) clutch through the CB26 hydraulic circuit. The CB26 hydraulic circuit also supplies pressure to the opposite side of the CB26 clutch regulator valve for controlled intermediate (2, 6) clutch engagement. Regulated overdrive (4, 5, 6) clutch pressure is supplied to the intermediate (2, 6) clutch regulator valve in 6th gear to boost the SSC solenoid pressure.

Low-Reverse Clutch Hydraulic Circuits

When the low-reverse clutch is applied in REVERSE, LINE pressure from the pump is directed to the multiplex shift valve by the manual valve through the REV hydraulic circuit to move the valve. Line pressure is also supplied to the low-reverse/overdrive clutch regulator valve from the pump. The low-reverse/overdrive clutch regulator valve is controlled by SSD and directs regulated pressure to the multiplex shift valve. The multiplex shift valve directs the regulated pressure to the low-reverse clutch through the CBLR SUPPLY circuit.

When the low-reverse clutch is applied in PARK, LOW or 1st gear below 8 kmh (5 mph), SSE pressure is supplied to the multiplex shift valve to move the valve. LINE pressure is supplied to the low-reverse/overdrive clutch regulator valve from the pump. The low-reverse/overdrive clutch regulator valve is controlled by SSD and directs regulated pressure to the multiplex shift valve. The multiplex shift valve directs the regulated pressure to the low-reverse clutch through the CBLR SUPPLY circuit.

Overdrive Clutch Hydraulic Circuits

When the overdrive clutch is applied in 4th, 5th and 6th gears, LINE pressure is supplied to the low-reverse/overdrive (4, 5, 6) clutch regulator valve from the pump. To apply the overdrive (4, 5, 6) clutch, SSD applies varying solenoid pressure to the CBLR/C456 regulator and boost valves. As the CBLR/C456 regulator valve moves, it supplies the multiplex shift valve assembly and CBLR/C456 boost valve with regulated line pressure through the CBLR/C456 SUPPLY circuit. The CBLR/C456 boost valve directs the regulated line pressure to the opposite side of the CBLR/C456 regulator valve through the CBLR/C456 FDBK circuit for controlled overdrive (4, 5, 6) clutch engagement. The multiplex shift valve directs the regulated pressure to the multiplex manual valve through the C456 SUPPLY hydraulic circuit. The multiplex manual valve directs the regulated pressure to the overdrive (4, 5, 6) clutch through the C456 hydraulic circuit. The C456 circuit also supplies pressure to the CB26 clutch regulator valve to boost the pressure from SSC in 6th gear.

Mechanical System

Component Location

1. Gear and shell assembly - front sun
2. Front planetary carrier/rear planetary ring gear assembly
3. Planetary carrier shell - front
4. Carrier - front planetary
5. Ring gear - rear planetary
6. Gear - center planetary sun
7. Center planetary carrier/front ring gear assembly
8. Ring gear - front planetary
9. Planetary carrier assembly - center
10. Rear planetary carrier/center ring gear assembly
11. Gear - center ring
12. Carrier - rear planetary
13. Gear - rear planetary sun
14. Transmission Case
15. Cover assembly

System Operation

System Diagram

Component Description

Planetary Gearset

This transmission has 3 planetary gearsets to provide operation in reverse and 6 forward speeds.

Front planetary gearset consists of the following components:

• Front planetary sun gear
• Front planetary carrier
• Front planetary ring gear

The front planetary sun gear is splined to the forward (1, 2, 3, 4) clutch and is held stationary in 1st, 2nd, 3rd and 4th gear.

The front planetary carrier is splined to the rear ring gear and transfers power from the rear planetary gearset to the front planetary gearset in 2nd, 3rd, 5th and 6th gear and reverse. The front planetary carrier is the output component for the planetary gearset as it is splined to the output hub.

The front planetary ring gear is splined to the center planetary carrier and transfers power from the center planetary gearset to the front planetary gearset in 1st, 2nd, 3rd and 4th gear.

Center planetary gearset consists of the following components:

• Center planetary sun gear
• Center planetary carrier
• Center planetary ring gear

The center planetary sun gear is splined to the input shaft and is used as input to the planetary gearsets in 1st, 2nd, 3rd, 4th and 5th gear.

The center planetary ring gear is splined to the rear planetary carrier. The center ring gear/rear planetary carrier is held stationary by the low OWC and low-reverse clutch in 1st gear and reverse. The center ring gear/rear planetary carrier is driven by the overdrive (4, 5, 6) clutch in 4th, 5th, and 6th gears.

Rear planetary gearset consists of the following components:

• Rear planetary ring gear
• Rear planetary carrier
• Rear planetary sun gear

The rear planetary carrier is splined to the overdrive (4, 5, 6) clutch hub and transfers power from the input shaft to the rear planetary carrier in 4th, 5th and 6th gear.

The rear planetary sun gear is splined to both the intermediate (2, 6) clutch and the direct (3, 5, R) clutch. The rear planetary sun gear is held stationary by the intermediate (2, 6) clutch in 2nd and 6th gear and is driven by the direct (3, 5, R) clutch in 3rd and 5th gear and reverse.

1. Gear and shell assembly - front sun
2. Front planetary carrier/rear planetary ring gear assembly
3. Planetary carrier shell - front
4. Carrier - front planetary
5. Ring gear - rear planetary
6. Gear - center planetary sun
7. Center planetary carrier/front ring gear assembly
8. Ring gear - front planetary
9. Planetary carrier assembly - center
10. Rear planetary carrier/center ring gear assembly
11. Gear - center ring
12. Carrier - rear planetary
13. Gear - rear planetary sun

Input Shaft

The input shaft is part of the direct/overdrive clutch assembly and is splined to the torque converter turbine and the center planetary sun gear. The input shaft transfers power from the torque converter to the rear planetary gearset through the direct (3, 5, R) and overdrive (4, 5, 6) clutches and the center planetary sun gear.

1. Input shaft (part of direct/overdrive clutch assembly)
2. Direct clutch
3. Overdrive clutch
4. Center planetary sun gear

Front Planetary Carrier Hub (Output Hub)

The front planetary carrier hub is splined to the front planetary carrier and the transfer shaft drive gear. This allows torque to be transferred from the planetary gearset to the final drive gearset.

1. Front planetary carrier
2. Front planetary carrier hub
3. Transfer shaft drive gear

Final Drive Gearset

The final drive consists of a gearset that transfers and multiplies torque from the planetary gearsets to the differential.

The final drive consists of the following components:

• Transfer shaft drive gear
• Transfer shaft and gear assembly
• Differential assembly
• Ring gear

The planetary gear set transfers power to the transfer shaft drive gear through the front planetary carrier hub. The transfer shaft drive gear is part of the stator support assembly. The transfer shaft drive gear turns the transfer shaft and gear assembly which multiplies torque through gear reduction and turns the differential ring gear.

1. Front planetary carrier hub
2. Transfer shaft drive gear
3. Transfer shaft drive gear bearing
4. Stator support assembly
5. Transfer shaft
6. Transfer gear
7. Differential assembly
8. Differential ring gear

Differential

The differential allows the half shafts and wheels to rotate at different speeds during cornering and transfers power to the PTU for AWD vehicles. The differential assembly consists of the following components:

• Differential case (part of the final drive carrier)
• Two pinion gears supported by a pinion shaft
• Two side gears supported by the differential case and half shafts

When driving in a straight line, both front wheels rotate at relatively the same speed. This means both side gears are rotating at the same speed, as well, while both pinion gears revolve (but do not rotate) with the side gears. During cornering, the wheel on the outside of the turn is forced to rotate faster than the wheel on the inside of the turn. Since the side gears must now rotate at different speeds, the pinion gears rotate on the pinion shaft allowing the drive axles to rotate at different speeds while still transferring output torque.

1. Differential housing
2. Pinion shaft
3. Pinion gears
4. Side gears

Forward (1, 2, 3, 4) Clutch

The forward clutch is a brake clutch that holds the front sun gear and shell assembly. The forward clutch is applied in 1st, 2nd, 3rd and 4th gear.

Hydraulic pressure from the regulator valve in the valve body pushes the forward clutch piston against the forward clutch pack to apply the clutch. The forward clutch pack is pushed against the low OWC when it is applied. The rear sun gear and shell assembly is held stationary to the transmission case as a result of the clutch being applied.

1. Low OWC snap ring
2. Low OWC
3. Forward clutch friction plates
4. Forward clutch steel plates
5. Forward clutch waved cushion spring
6. Forward clutch piston snap ring
7. Forward clutch piston return spring
8. Forward clutch piston
9. Front sun gear and shell assembly
10. Transmission case

Direct (3, 5, R) Clutch

The direct clutch is a drive clutch that transfers power from the direct/overdrive hub and shaft assembly to the rear sun gear. The direct clutch is applied in 3rd and 5th gear and reverse.

Hydraulic pressure from the regulator valve in the valve body pushes the direct clutch piston against the direct clutch pack to apply the clutch. The input shaft transfers torque to the rear planetary sun gear as a result of the clutch being applied.

1. Snap ring - direct clutch cylinder
2. Direct clutch cylinder
3. Direct clutch piston
4. Return spring - direct clutch piston
5. Direct clutch piston seals
6. Input shaft (part of direct/overdrive clutch assembly)
7. Direct clutch friction plates
8. Direct clutch wave spring
9. Direct clutch steel plates
10. Direct clutch pressure plate
11. Direct clutch snap ring
12. Rear planetary sun gear and shell assembly

Intermediate (2, 6) Clutch

The intermediate clutch is a brake clutch that holds the rear sun and shell assembly. The intermediate clutch is applied in 2nd and 6th gear.

Hydraulic pressure from the regulator valve in the valve body pushes the intermediate clutch piston against the intermediate clutch pack to apply the clutch. The rear planetary sun gear is held stationary to the transmission case as a result of the clutch being applied.

1. Cover assembly
2. Intermediate clutch piston
3. Intermediate clutch piston return spring
4. Intermediate clutch piston return spring snap ring
5. Rear planetary sun gear
6. Intermediate clutch steel plates
7. Intermediate clutch friction plates
8. Intermediate clutch pressure plate
9. Transmission case

Low-Reverse Clutch

The low/reverse clutch is a brake clutch that holds the low OWC which is splined to the rear planetary carrier. The low/reverse clutch is applied in manual LOW, REVERSE and 1st gear up to 8 kmh (5 mph).

Hydraulic pressure from the regulator valve, routed through the multiplex shift valve in the valve body, pushes the low/reverse clutch piston against the low/reverse clutch pack to apply the clutch. The rear planetary carrier is held stationary to the transmission case as a result of the clutch being applied.

1. Cover assembly
2. Low/reverse clutch piston
3. Low/reverse clutch piston return spring
4. Low/reverse clutch return spring snap ring
5. Low/reverse clutch steel plates
6. Low/reverse clutch friction plates
7. Rear planetary carrier
8. Low OWC snap ring
9. Low OWC
10. Transmission case

Overdrive Clutch

The overdrive clutch is a drive clutch that transfers power from the direct/overdrive hub and shaft assembly to the rear planetary carrier. The overdrive clutch is applied in 4th, 5th and 6th gear.

Hydraulic pressure from the regulator valve in the valve body pushes the overdrive clutch piston against the overdrive clutch pack to apply the clutch. The input shaft transfers torque to the rear planetary sun gear as a result of the clutch being applied.

1. Input shaft (part of direct/overdrive clutch assembly)
2. Overdrive clutch piston inner seal
3. Overdrive clutch piston outer seals
4. Overdrive clutch piston
5. Overdrive clutch piston return spring
6. Overdrive clutch balance piston
7. Overdrive clutch balance piston snap ring
8. Overdrive clutch steel plates
9. Overdrive clutch friction plates
10. Overdrive clutch pressure plate
11. Overdrive clutch snap ring
12. Overdrive clutch hub thrust bearing
13. Overdrive clutch hub
14. Rear sun gear thrust bearing
15. Rear planetary carrier

Low One-Way Clutch

The low OWC is a brake clutch that holds the rear planetary carrier in one direction and allows it to freewheel in the opposite direction which eliminates engine braking in 1st gear when the transmission is in DRIVE. The low OWC is used in 1st gear when the transmission is in DRIVE.

1. Rear planetary carrier
2. Low OWC snap ring
3. Low OWC
4. Transmission case