Manual Power Train Caterpillar 777d Off Highway Truck Components 3e3u5r
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Service Training MALAGA
777D Off Highway Truck LOCKUP CLUTCH VALVE TORQUE CONVERTER DRIVE
LOAD PISTON
MODULATION REDUCTION VALVE
SELECTOR PISTON
LOAD PISTON ORIFICE PRESSURE REDUCTION VALVE
LOCKUP SOLENOID OFF
SHUTTLE VALVE
TO LOCKUP CLUTCH
FROM PARKING BRAKE PUMP
III. POWER TRAIN 1. 2. 3. 4.
Components Layout Operation Maintenance Testing & Adjusting Adolfo August 1997
777D Off Highway Truck CHAPTER : Power Train
TYPICAL OFF-HIGHWAY TRUCK POWER TRAIN COMPONENT LOCATIONS LOCKUP MODULATION VALVE
LOCKUP SOLENOID
TRANSMISSION PUMP TORQUE CONVERTER SOLENOIDS UPSHIFT DOWNSHIFT
TRANSMISSION
TRANSMISSION OIL FILTER
TORQUE CONVERTER FILTER
TORQUE CONVERTER AND TRANSMISSION OIL
INLET AND OUTLET RELIEF VALVES
TRANSMISSION
DRIVE SHAFT
TRANSMISSION CONTROL VALVE DIFFERENTIAL AND FINAL DRIVES
LOCKUP CLUTCH TORQUE CONVERTER
Page:
III-2
TORQUE TRANSFER CONVERTER GEARS PUMP
777D Off Highway Truck CHAPTER : Power Train
TORQUE CONVERTER CONVERTER DRIVE
TURBINE LOCKUP PISTON
TORQUE CONVERTER INLET OIL IMPELLER TORQUE CONVERTER LOCKUP OIL AGE
ENGINE FLYWHEEL
STATOR
FREEWHEEL ASSEMBLY
Page:
III-3
TO TRANSFER GEARS
777D Off Highway Truck CHAPTER : Power Train
TORQUE CONVERTER DIRECT DRIVE
TURBINE LOCKUP PISTON
TORQUE CONVERTER INLET OIL
IMPELLER
TORQUE CONVERTER LOCKUP OIL AGE
ENGINE FLYWHEEL
STATOR
FREEWHEEL ASSEMBLY
Page:
III-4
TOTRANSFER GEARS
Page: III-5
LOCKUP CLUTCH VALVE CLUTCH FILLING
LOAD PISTON
SELECTOR PISTON SHIMS
LOAD PISTON ORIFICE
LOCKUP SOLENOID ON
SHUTTLE VALVE
TO LOCKUP CLUTCH
FROM PARKING BRAKE PUMP
777D Off Highway Truck
PRESSURE REDUCTION VALVE
CHAPTER : Power Train
MODULATION REDUCTION VALVE
Page: III-6
LOCKUP CLUTCH VALVE DIRECT DRIVE
LOAD PISTON
SELECTOR PISTON
LOAD PISTON ORIFICE
LOCKUP SOLENOID ON
SHUTTLE VALVE
TO LOCKUP CLUTCH
FROM PARKING BRAKE PUMP
777D Off Highway Truck
PRESSURE REDUCTION VALVE
CHAPTER : Power Train
MODULATION REDUCTION VALVE
Page: III-7
769D - 777D TORQUE CONVERTER HYDRAULIC SYSTEM NEUTRAL
INLET RELIEF VALVE BRAKE COOLING PRESSURE
LOCKUP CLUTCH PILOT OIL PRESSURE
LOCKUP CLUTCH PRESSURE
LOCKUP MODULATION PARKING BRAKE VALVE RELIEF VALVE TO BRAKE COOLING CIRCUIT
OUTLET RELIEF VALVE
OUTLET PRESSURE TAP
INLET PRESSURE LOCKUP REDUCING VALVE
PARKING BRAKE RELEASE VALVE
CONVERTER CHARGING PUMP
PARKING BRAKE RELEASE PUMP
PARKING BRAKE RELEASE PRESSURE
LOCKUP CLUTCH
CONVERTER SCAVENGE PUMP SCREEN
TORQUE CONVERTER
SHIMS
777D Off Highway Truck
TO BRAKE COOLING CIRCUIT
CHAPTER : Power Train
LOCKUP SOLENOID
Page: III-8
769D - 777D TRANSMISSION HYDRAULIC SYSTEM NEUTRAL
DOWNSHIFT PRESSURE
UPSHIFT PRESSURE
A DOWNSHIFT UPSHIFT SOLENOID SOLENOID ROTARY ACTUATOR
FILTER
E
ON PUMP PRESSURE
B NEUTRALIZER VALVE
OIL COOLER
F ROTARY SELECTOR SPOOL
C
SCAVENGE PUMP
G
D
RELIEF VALVE
H
TRANSMISSION CASE
TANK
LUBE RELIEF VALVE
SELECTOR VALVE GROUP LUBE PRESSURE
PRESSURE CONTROL GROUP
777D Off Highway Truck
CHARGING PUMP
PRIORITY REDUCTION VALVE
CHAPTER : Power Train
PILOT OIL PRESSURE
777D Off Highway Truck CHAPTER : Power Train
769D - 777D TRANSMISSION SELECTOR VALVE GROUP NEUTRAL
NEUTRALIZER VALVE ROTARY SELECTOR SPOOL PRIORITY REDUCTION VALVE PILOT OIL PRESSURE SCREEN RELIEF VALVE
TRANSM. LUBE RELIEF VALVE
LUBRICATION PRESSURE
Page:
III-9
777D Off Highway Truck CHAPTER : Power Train
769C - 777C TRANSMISSION SELECTOR VALVE GROUP STARTING IN FIRST SPEED FORWARD
NEUTRALIZER VALVE
ROTARY SELECTOR SPOOL
PRIORITY REDUCTION VALVE
PILOT OIL PRESSURE SCREEN RELIEF VALVE
LUBE RELIEF VALVE
LUBRICATION PRESSURE
Page:
III-10
777D Off Highway Truck CHAPTER : Power Train
769D - 777D PRESSURE CONTROL GROUP NEUTRAL
A
E B
F
C
G D
H
Page:
III-11
Page: III-12
VALVE STATION CLUTCH RELEASED
SELECTOR PISTON SLUG
BALL CHECK VALVE
LOAD PISTON
PILOT OIL AGE
MODULATION REDUCTION VALVE FROM PUMP
LOAD PISTON PLUG
CLUTCH PRESSURE TAP TO CLUTCH
777D Off Highway Truck
DECAY ORIFICE LOAD PISTON ORIFICE
CHAPTER : Power Train
PLUG
777D Off Highway Truck CHAPTER : Power Train
VALVE STATION CLUTCH ENGAGED
Page:
III-13
777D Off Highway Truck CHAPTER : Power Train
VALVE STATION CLUTCH ENGAGED/WITH PIN
Page:
III-14
777D Off Highway Truck CHAPTER : Power Train
VALVE STATION CLUTCH DECAY
DECAY ORIFICE
Page:
III-15
Page: III-16
769C - 777C TRANSMISSION HYDRAULIC SYSTEM THIRD SPEED FORWARD
DOWNSHIFT PRESSURE
UPSHIFT PRESSURE
A DOWNSHIFT UPSHIFT SOLENOID SOLENOID ROTARY ACTUATOR
FILTER
E PUMP PRESSURE
B
OIL COOLER CHARGING PUMP
PRIORITY REDUCTION VALVE
F ROTARY SELECTOR SPOOL
C
SCAVENGE PUMP
G D RELIEF VALVE
H
TRANSMISSION CASE
TANK
LUBE RELIEF VALVE SELECTOR VALVE GROUP LUBE PRESSURE
PRESSURE CONTROL GROUP
777D Off Highway Truck
PILOT OIL PRESSURE
CHAPTER : Power Train
NEUTRALIZER VALVE
777D Off Highway Truck CHAPTER : Power Train
VALVE STATION PRIMARY PRESSURE
LOAD PISTON PLUG (REMOVED)
Page:
III-17
Page: III-18
777D SHIFT MODULATION CYCLE THIRD(3&6) TO FOURTH (1&5)
PRESSURE NORMAL SHIFT CYCLE CLUTCH 1 418
CLUTCH 5
CLUTCH 3
COMPLETE CLUTCH ENGAGEMENT
PRIMARY PRESSURE 50
INITIAL CLUTCH ENGAGEMENT
0 FILL TIME NORMAL CLUTCH SLIP
TIME
777D Off Highway Truck
265
CLUTCH 6
CHAPTER : Power Train
373 353
Page: III-19
777C SHIFT MODULATION CYCLE SECOND TO THIRD PRESSURE NORMAL SHIFT CYCLE
418 373
CLUTCH 3
COMPLETE CLUTCH ENGAGEMENT
80
PRIMARY PRESSURE
INITIAL CLUTCH ENGAGEMENT
0 FILL TIME NORMAL CLUTCH SLIP
TIME
777D Off Highway Truck
CLUTCH 1 265
CHAPTER : Power Train
CLUTCH 6
Page: III-20
PRESSURE HIGH PRIMARY PRESSURE
RESTRICTED LOAD PISTON ORIFICE SLOW MODULATION P1
COMPLETE CLUTCH ENGAGEMENT
0
TIME
HIGH PRIMARY PRESSURE - HARSH SHIFT NORMAL CLUTCH SLIP LOW PRIMARY PRESSURE - CLUTCH SLIPPING
SHIFT MODULATION PROBLEMS RESTRICTED LOAD PISTON ORIFICE CLUTCH SLIPPING
777D Off Highway Truck
NORMAL PRIMARY PRESSURE
CHAPTER : Power Train
LOW PRIMARY PRESSURE INITIAL CLUTCH ENGAGEMENT
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab A: Component Location and Identification Worksheet I 769D - 777D Off-highway Trucks Torque Converter Hydraulic System Directions: Refer to the Lab A Handout Illustration Worksheet V. Place the correct letter or number next to the component. During the slide presentation, use this sheet to take notes on the function of each component. ______ Torque Converter - example: Located on the rear of the engine. Provides a fluid coupling between the engine and the transmission and multiplies torque. Contains a lockup clutch for more efficient operation. ______ Torque Converter Pump (1. Scavenge, 2. Charging, and 3. Park Brake Release) -
______ Torque Converter Scavenge Screen -
______ Torque Converter Charging Filter -
______ Torque Converter Inlet Relief Valve -
______ Torque Converter Outlet Relief Valve -
______ Torque Converter Lockup Clutch Valve -
______ Parking Brake Release Valve -
______ Parking Brake Release Filter -
______ Lockup Clutch Solenoid Valve -
Page:
III-21
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab A: Component Location and Identification Worksheet ID 769D - 777D Off-highway Trucks Transmission Hydraulic System Directions: Refer to the Lab A Handout Illustration Worksheet V. Place the correct letter or number next to the component. During the slide presentation, use this sheet to take notes on the function of each component. ______ Transmission Tank - example: Located on the left side of the truck. Contains a sight gauge for checking power train hydraulic level. ______ Transmission Pump -
______ Transmission Filter -
______ Transmission Magnetic Suction Screen -
______ Transmission Oil Cooler -
______ Transmission Control Valve -
______ Upshift Solenoid Valve -
______ Downshift Solenoid Valve -
Page:
III-22
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab A: Component Location and Identification Worksheet V Torque Converter and Transmission Hydraulic Systems Component Identification
TYPICAL OFF-HIGHWAY TRUCK POWER TRAIN COMPONENT LOCATIONS
Page:
III-23
TO BRAKE COOLING CIRCUIT
TO BRAKE COOLING CIRCUIT
B. Parking Brake Release Pressure C. Lockup Clutch Pressure D. Outlet Pressure E. Pilot Pressure
Identify Components 1. Outlet Relief Valve
7. Inlet Relief Valve
2. Parking Brake Release Valve
8. Lockup Modulation Valve
3. Converter Charging Pump
9. Scavenge Pump
III-24
4. Torque Converter
10. Lockup Solenoid
5. Lockup Reducing Valve
11. Shuttle Valve
6. Parking Brake Release Pump
12. Lockup Clutch
777D Off Highway Truck
Page:
Directions: Write the letter or number of the item in the correct blank on the schematic.
A. Inlet Pressure
CHAPTER : Power Train
Worksheet I: (769D - 777D)
Identify Test Ports
LAB EXERCISES
Lab B: Torque Converter Hydraulic System Component Identification
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab C: Torque Converter Hydraulic System Testing Shop Lab Exercise Procedure: Perform the following tests listed in the Power Train Testing and Adjusting Service Manual Module for the lab machine used: • Visual Checks (8) for the hydraulic system which include Brake Cooling, Torque Converter, and Hoist Hydraulic Systems • Torque Converter Outlet Pressure • Torque Converter Inlet Pressure • Parking Brake Release Pressure • Lockup Clutch Pilot Pressure • Lockup Clutch Leakage • Lockup Clutch Signal Pressure (785B - 793B) • Lockup Clutch Maximum Pressure • Lockup Clutch Primary Pressure Class notes Lab D Worksheets (I and II) Off-highway Truck Mechanic's tools The following test equipment: 1 - 8T0854 Gauge 1000 kPa (145 psi) 1 - 8T0850 Gauge 4000 kPa (580 psi) 1 - 8T0851 Gauge 16000 kPa (2300 psi) 1 - 6V3965 Nipple 1 - 6V4143 Valved Coupler 1 - 6V3079 Diagnostic Hose 1 - 6V3121 Multitach Group 1 - Oil container [approximately 19 l (5 gal.) capacity] 1 - Special Instruction "6V3121 Multitach Group" (Form SEHS7807)
Page:
III-25
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab C: Torque Converter Hydraulic System Testing 769C - 777C Off-highway Trucks - Worksheet I Directions: Use this sheet to check off each of the steps listed in the Power Train Testing and Adjusting Service Manual Module. Machine Model______________________ Name/Code _________________________ Machine PIN (S/N)___________________ Transmission S/N ____________________ Engine S/N _________________________ S.M.H. ____________________________
Dealer ______________________________ Customer ___________________________ Job ________________________________ Application __________________________ Date _______________________________ Serviceman __________________________
VISUAL CHECKS ______ Check 1 - Oil levels in the hydraulic tank ______ Check 5 - Torque converter scavenge screen ______ Check 2 - External Leakage
______ Check 6 - Oil cooler screens
______ Check 3 - Parking brake release oil filter ______ Check 7 - Components inside hydraulic tank ______ Check 4 - Torque converter oil filter
TEST
______ Check 8 - Inspect return oil screen
SPECS
ACTUAL
Torque Converter Outlet Pressure at Stall Torque Converter Stall Speed Torque Converter Inlet Pressure Lockup Clutch Pilot Pressure Parking Brake Release Pressure Lockup Clutch Leakage Lockup Clutch Maximum Pressure Lockup Clutch Primary Pressure
Page:
III-26
Lab D: Tracing Torque Converter Oil System Flow (769D - 777D) Worksheet I Directions: Trace the flow of oil during the condition listed below using different colored pencils to show each path.
TO BRAKE COOLING CIRCUIT
III-27
777D Off Highway Truck
CHAPTER : Power Train
Page:
769D - 777D TORQUE CONVERTER HYDRAULIC SYSTEM TORQUE CONVERTER DRIVE
LAB EXERCISES
TO BRAKE COOLING CIRCUIT
Lab D: Tracing Torque Converter Oil System Flow (769D - 777D) Worksheet II Directions: Trace the flow of oil during the condition listed below using different colored pencils to show each path.
TO BRAKE COOLING CIRCUIT
TO BRAKE COOLING CIRCUIT
III-28
777D Off Highway Truck
CHAPTER : Power Train
LAB EXERCISES
Page:
769C - 777C TORQUE CONVERTER HYDRAULIC SYSTEM DIRECT DRIVE
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab E: Torque Converter Hydraulic System Operation (769D - 777D) Worksheet I Directions: Circle the letter of the correct statement that completes the sentence. Example: Torque converter leakage oil is removed from the torque converter by the: A. Parking brake release pump B. Scavenge pump C. Charging pump 1. The torque converter is in direct drive in the following speeds:
5. When the lockup solenoid opens and the shuttle valve moves, the shuttle valve:
A. REVERSE and FIRST
A. opens a age to drain
B. second half of FIRST through SEVENTH
B. closes a age to drain
C. NEUTRAL to FIRST
C. directs lockup clutch oil to the lockup clutch
2. If the torque converter lockup solenoid does not 6. Torque converter operating pressure is receive an electrical signal in SECOND SPEED maintained by the: FORWARD, the torque converter will: A. inlet relief valve A. stay in DIRECT DRIVE B. outlet relief valve B. go to DIRECT DRIVE C. parking brake release valve C. go to TORQUE CONVERTER DRIVE 7. Modulation of the lockup clutch is determined 3. The source of torque converter lockup oil is by the: from the: A. load piston A. transmission charging pump B. modulation reducing valve B. torque converter charging pump C. load piston orifice C. parking brake release pump 4. Excess oil pressure to the torque converter during a cold start-up is prevented by the _______. A. inlet relief valve B. outlet relief valve C. parking brake release valve
Page:
III-29
A E
ON
B F C G
Identify Test Ports
Identify Components
6. Priority Reduction Valve
12. Neutralizer valve
7. Main Relief Valve
13. Oil Cooler
B. Pump Pressure
2. Pressure Control Group
8. Scavenge Pump
14. Filter
C. Lube Pressure
3. Rotary Selector Spool
9. Downshift Solenoid
15. Screen
III-30
1. Charging Pump
Page:
A. Downshift Pressure
Worksheet I
Directions: Write the letter or D. Upshift Pressure number of the item in the correct blank on the schematic. E. Pilot Pressure
4. Upshift Solenoid
10. Rotary Actuator
5. Lube Relief Valve
11. Selector Valve Group
16. A to C and E to H
777D Off Highway Truck
Lab F: Transmission Hydraulic System Component Identification (769D - 777D)
CHAPTER : Power Train
H
LAB EXERCISES
D
VALVE STATION
Lab F: Transmission Hydraulic System Component Identification Pressure Control Group Valve Station Worksheet III Directions: Write the letter or number of the item in the correct blank on the schematic.
B. Pilot Pressure
7. Load Piston Orifice
9. Decay Orifice
3. Load Piston Plug 4. Pilot Oil age
10. Clutch Pressure Tap
III-31
8. Load Piston
Page:
2. Selector Piston
5. Pin
11. Slug
6. Pilot Oil Plug
12. Modulation Reduction Valve
777D Off Highway Truck
Identify Components Identify Test Ports 1. Ball Check Valve A. Primary and Clutch Pressures
CHAPTER : Power Train
TO CLUTCH
LAB EXERCISES
FROM PUMP
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab G: Transmission Hydraulic System Testing Shop Lab Exercise Procedures: Perform the following tests listed in the Power Train Testing and Adjusting Service Manual Module for the lab machine used: • Visual Checks (6) • Transmission Pump Pressure • Transmission Lubrication Pressure • Pilot Pressure • Pressure Control Group Clutch Pressures • Primary Clutch Pressures • Dual Stage Relief Valve Pressure Class notes Lab G Worksheets (I and II) Off-highway Truck Mechanic's tools The following test equipment: 1 - 1U5481 Pressure Gauge Group 1 - 1U5482 Pressure Adaptor Group 1 - 3B7282 Nipple 1 - 3B6552 Nipple 1 - 6V4142 Unvalved Nipple 1 - 6V6064 or FT1775 Transmission Test Cover
Page:
III-32
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab G: Transmission Hydraulic System Testing 769D - 793C Off-highway Trucks - Worksheet I Directions: Use this sheet to check off each of the steps listed in the Power Train Testing and Adjusting Service Manual Module. All tests should be run with the transmission in NEUTRAL. Machine Model______________________ Name/Code _________________________ Machine PIN (S/N)___________________ Transmission S/N ____________________ Engine S/N _________________________ S.M.H. ____________________________
Dealer ______________________________ Customer ___________________________ Job ________________________________ Application __________________________ Date _______________________________ Serviceman __________________________
VISUAL CHECKS ______ Check 1 - Oil levels in the hydraulic tank ______ Check 5 - Transmission case oil quantity ______ Check 2 - External leakage
______ Check 6 - Transmission oil tank debris
______ Check 3 - Oil filter examination ______ Check 4 - Magnetic screen debris DU AL S TAGE RELIEF
LOCKU P CLU TCH DEACTIVATED S PECS LOW IDLE
HIGH IDLE
ACTU AL LOW IDLE
HIGH IDLE
PU MP PRES S U RE DU AL S TAGE RELIEF
LOCKU P CLU TCH ACTIVATED S PECS LOW IDLE
HIGH IDLE
ACTU AL LOW IDLE
HIGH IDLE
PU MP PRES S U RE S PECS LOW IDLE PILOT PRES S U RE
HIGH IDLE NO
ACTU AL LOW IDLE
HIGH IDLE NO
LU BE PRES S U RE
Page:
III-33
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab G: Transmission Hydraulic System Testing 769D - 793C Off-highway Trucks - Worksheet II Directions: Use this sheet to check off each of the steps listed in the Power Train Testing and Adjusting Service Manual Module.
CLU TCH CHART N
PRIMARY CLU TCH PRES S U RE AT LOW IDLE (LOAD PIS TON PLU G REMOVED) STATION CLUTCH SPECS ACTUAL
R
A
1
B
2
C
3
D
4
E
5
F
6
G
7
H
PRIMARY CLU TCH PRES S U RE AT LOW IDLE (LOAD PIS TON PLU G IN S TALLED) S PECS ACTU AL S TATION
CLU TCH
LOW IDLE
HIGH IDLE
LOW IDLE
HIGH IDLE
A B C D E F G H
Page:
III-34
777D Off Highway Truck CHAPTER : Power Train
POSTTEST As this component moves and closes a drain age, modulation will begin
1. Load Piston 2. Pilot Oil age
Removal of this component allows the technician to check pilot pressure Allows oil from the rotary selector spool to move the selector piston Controls the rate of clutch engagement Works with the modulation reduction valve to control clutch pressure
3. Decay Orifice 4. Load Piston Plug 5. Modulation Reduction Valve 6. Load Piston Orifice 7. Ball Check Valve
Allows clutch pressure to be directed into the center chamber of the modulation reduction valve
8. Clutch Pressure Tap
Allows the technician to check clutch pressure
9. Pilot Pressure Plug
Removal of this component causes the clutch pressure to remain at the primary pressure
10. Selector Piston 11. Slug
Controls the rate of clutch release Works with load piston to control clutch pressure Directions: Modified True/False. If a statement is false, underline or circle the word or words that make the statement incorrect and replace with word(s) to make the statement correct. (Each question is worth 2 points.) a transmission Example: F 1. This is an engine class. 1. To initiate clutch filling, pilot oil moves the selector piston. 2. The size of the modulation reducing valve determines the rate of clutch modulation. 3. To check the primary clutch pressure, remove the load piston plug. 4. Pins in a clutch station increase the modulation time. 5. Clutch release time is determined by the decay orifice.
Page:
III-35
Directions: Match the components and test ports with the associated number or letter. (Each question is worth 1 point.)
13
Test Ports
1
Primary Pressure
VALVE STATION
15
14
Pilot Pressure
10
Clutch Pressure
11
Components
Load Piston Plug
9
Modulation Reduction Valve Load Piston Orifice Ball Check Valve Clutch Pressure Tap Page:
Pilot Oil Plug Selector Piston
III-36
Slug Pin
2
6 5 FROM PUMP
4 TO CLUTCH
3 8
12
777D Off Highway Truck
Decay Orifice
CHAPTER : Power Train
7
Pilot Oil age
POSTTEST
Load Piston
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Directions: Use the schematic on page 38. After each statement, circle the correct sequence of events that occurs. Example: The operator makes a shift from NEUTRAL to FIRST FORWARD. C. 1-Modulation begins A. 1-Pilot oil moves B. 1-Selector piston closes selector piston drain 2-Load piston moves reducing valve 2-Selector piston closes 2-Pilot oil moves drain selector piston 3-Selector piston closes drain 3-Load piston moves 3-Modulation begins reducing valve 4-Pilot oil moves 4-Load piston moves selector piston 4-Modulation begins reducing valve
A. 1-Rotary selector spool opens pilot oil age to drain 2-Load piston oil is directed through decay orifice 3-Selector piston opens drain
A. 1-Pump oil is directed through load piston orifice 2-Pump oil is directed to clutch 3-Modulation reduction valve moves
B. 1-Rotary selector spool opens pilot oil age to drain
C. 1-Selector piston opens drain
2-Selector piston opens drain
2-Load piston oil is directed through decay orifice
3-Load piston oil is directed through decay orifice
3-Rotary selector spool opens pilot oil age to drain
B. 1-Pump oil is directed to clutch
C. 1-Modulation reduction valve moves
2-Modulation reduction valve moves
2-Pump oil is directed to clutch
3-Pump oil is directed through load piston orifice
3-Pump oil is directed through load piston orifice
Page:
III-37
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Torque Converter Hydraulic System Posttest (769D - 777D) Directions: Match the component to its primary function. Maintains high oil pressure to the lockup reducing valve
1. Lockup Solenoid
Supplies oil for hydraulic energy transfer
2. Inlet Relief Valve
Maintains working pressure within the torque converter
3. Torque Converter
When energized, supplies pilot oil to initiate direct drive
4. Lockup Reducing Valve
Relieves excess pressure to the torque converter
5. Parking Brake Release Valve
Provides a controlled rate of engagement of the lockup clutch
6. Outlet Relief Valve
Transfers engine power to the transmission
7. Lockup Modulation Valve
Reduces pump supply pressure to pilot pressure
8. Converter Charging Pump
Supplies oil to the lockup clutch
9. Diverter Valve 10. Parking Brake Release Pump
Directions: Modified True/False. If a statement is false, underline or circle the word or words that make the statement incorrect and replace with word(s) to make the statement correct. a power train Example: F 1. This is an engine class. 1. The inlet relief valve controls the maximum pressure in the torque converter. 2. The parking brake release pump supplies oil to the lockup modulation valve. 3. Lockup clutch oil pressure is controlled by the parking brake release valve. 4. Transmission oil pressure is used to pressurize the torque converter lockup clutch when the torque converter is in direct drive. 5. When the transmission is in REVERSE, the torque converter is in direct drive. 6. Direct drive is in gears FIRST through SEVENTH.
Page:
III-38
Directions: Match the components and test ports with the associated number or letter.
Test Ports Parking Brake Release Pressure Pilot Pressure E
Outlet Pressure Inlet Pressure
1
TO BRAKE COOLING CIRCUIT
Lockup Clutch Pressure
7 10
TO BRAKE COOLING CIRCUIT
A 5
Components
Parking Brake Release Valve
2
12 6 B 3
Outlet Relief Valve Lockup Modulation Valve Converter Charging Pump Page:
Scavenge Pump
III-39
Parking Brake Release Pump Shuttle Valve
9
769D - 777D TORQUE CONVERTER HYDRAULIC SYSTEM
777D Off Highway Truck
11
Torque Converter
CHAPTER : Power Train
Inlet Relief Valve
POSTTEST
4
Lockup Solenoid
Lockup Reducing Valve
D
C
8
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Directions: Use the schematic on page 41. After each statement, circle the correct sequence of events that occurs. Example: The operator makes a shift from NEUTRAL to FIRST FORWARD and the ground speed increases. A. 1-Torque converter is in TC drive 2-Ground speed increases and the lockup clutch modulation valve is activated 3-Lockup clutch engages
A. 1-Parking brake release oil directed to lockup modulation valve spool 2-Pilot oil directed to lockup solenoid valve 3-Parking brake release pump directs oil to lockup reducing valve
A. 1-Shuttle valve moves and blocks drain 2-Load piston moves 3-Lockup solenoid valve opens
A. 1-Shuttle valve moves and opens drain 2-Lockup solenoid valve closes 3-Load piston moves
B. 1-Lockup clutch engages 2-Ground speed increases and the lockup clutch modulation valve is activated 3-Torque converter is in TC drive
B. 1-Parking brake release oil directed to lockup modulation valve spool 2-Parking brake release pump directs oil to lockup reducing valve 3-Pilot oil directed to lockup solenoid valve
B. 1-Lockup solenoid valve opens 2-Shuttle valve moves and blocks drain 3-Load piston moves
B. 1-Load piston moves 2-Shuttle valve moves and opens drain 3-Lockup solenoid valve closes
C. 1-Ground speed increases and the lockup clutch modulation valve is activated 2-Lockup clutch engages 3-Torque converter is in TC drive
C. 1-Parking brake release pump directs oil to lockup reducing valve 2-Pilot oil directed to lockup solenoid valve 3-Parking brake release oil directed to lockup modulation valve spool
C. 1-Load piston moves 2-Lockup solenoid valve opens 3-Shuttle valve moves and blocks drain
C. 1-Lockup solenoid valve closes 2-Shuttle valve moves and opens drain 3-Load piston moves
Page:
III-40
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Directions: Match the component to its primary function.
Regulates pressure inside oil cooler Reduces temperature of transmission oil Removes oil from transmission case
1. Charging Pump 2. Pressure Control Group 3. Rotary Selector Spool 4. Upshift Solenoid
Maintains pilot oil pressure Removes debris from transmission oil Supplies modulated pressures to clutches
5. Oil Cooler Relief Valve 6. Priority Reduction Valve 7. Main Relief Valve 8. Scavenge Pump
Directs oil to move rotary actuator vane clockwise Maintains maximum system pressure Chooses appropriate clutch combinations for each speed
9. Downshift Solenoid 10. Rotary Actuator 11. Selector Valve Group 12. Neutralizer Valve
Six valve clutch stations Moves rotary selector spool Keeps machine from moving if transmission is started in gear
13. Oil Cooler 14. Filter 15. Manifold 16. A through H
Supplies oil to all clutches Directs oil to move rotary actuator vane counterclockwise Maintains and directs oil pressures to the pressure control group
Page:
III-41
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Directions: Modified True/False. If a statement is false, underline or circle the word or words that make the statement incorrect and replace with word(s) to make the statement correct. a transmission Example: F 1. This is an electrical test. 1. In NEUTRAL, no clutches are engaged. 2. If the machine is started IN GEAR, the neutralizer valve stops the flow of pilot oil. 3. Clutch pressure is maintained by the relief valve. 4. Reverse is an upshift. 5. During a shift, clutches are always drained and then refilled. 6. REVERSE and the first half of FIRST are torque converter drive.
Page:
III-42
Test Ports Pump Pressure
Directions: Match the components and test ports with the associated number or letter.
Upshift Pressure Downshift Pressure Pilot Pressure Lube Pressure Components Scavenge Pump Priority Reduction Valve
D
A
A
Rotary Selector Spool
9
4
14
Neutralizer Valve
12
Pressure Control Group Main Relief Valve
1
6
E 13
F 3
C
8 G
Charging Pump D
7
Downshift Solenoid
H
Filter Selector Valve Group Page:
Upshift Solenoid
15
16
5 11 C
Oil Cooler Rotary Actuator
III-43
Screen
769D- 777D TRANSMISSION HYDRAULIC SYSTEM
2
777D Off Highway Truck
A to C and E to H
CHAPTER : Power Train
B
POSTTEST
B
Lube Relief Valve
E
10
ON
777D Off Highway Truck CHAPTER : Power Train Directions: Use the schematic on page 45. After each statement, circle the correct sequence of events that occurs. Example: The operator has moved the shift lever from NEUTRAL to FIRST FORWARD. A. 1-Downshift solenoid is de-energized 2-Upshift solenoid is energized
B. 1-Rotary actuator moves to FIRST SPEED FORWARD
3-Rotary actuator moves to FIRST SPEED FORWARD
C. 1-Upshift solenoid is energized
2-Downshift solenoid is de-energized
2-Rotary actuator moves to FIRST SPEED FORWARD
3-Upshift solenoid is energized
3-Downshift solenoid is de-energized
1. The engine is started with the transmission in NEUTRAL. A. 1-Neutralizer valve moves 2-Pilot oil flows through rotary selector spool to one station
B. 1-Pilot oil flows through rotary selector spool to one station 2-Downshift solenoid is energized
3-Downshift solenoid is energized
3-Neutralizer valve moves
C. 1-Downshift solenoid is energized 2-Neutralizer valve moves 3-Pilot oil flows through rotary selector spool to one station
2. The engine is started with the gear shift lever in FIRST SPEED FORWARD. A. 1-Charge pump oil flows to priority reduction valve
B. 1-Rotary selector spool blocks charge pump oil to neutralizer valve
C. 1-Pilot oil flows to neutralizer valve
2-Pilot oil flows to neutralizer valve
2-Pilot oil flows to neutralizer valve
2-Rotary selector spool blocks charge pump oil to neutralizer valve
3-Rotary selector spool blocks charge pump oil to neutralizer valve
3-Charge pump oil flows to priority reduction valve
3-Charge pump oil flows to priority reduction valve
3. During an upshift, the following occurs: A. 1-Charge pump moves the upshift valve 2-Upshift solenoid is energized 3-Rotary actuator oil moves the downshift valve
B. 1-Upshift solenoid is energized 2-Charge pump oil moves the rotary actuator 3-Rotary actuator moves the rotary selector spool
C. 1-Rotary actuator oil moves the downshift valve 2-Upshift solenoid is energized 3-Charge pump moves the upshift valve
Page:
III-44
777D Off Highway Truck CHAPTER : Power Train Directions: After each statement, circle T if the statement is TRUE, and F if the statement is FALSE. Example: When activated, the shift solenoids allow oil to flow to the rotary actuator.
T
F
1. On some ICM transmissions, the Dual Stage Relief Valve is activated during torque converter lockup.
T
F
2. On all ICM transmission controls, REVERSE is an upshift from NEUTRAL and the downshift solenoid is activated whenever the shift lever is in NEUTRAL.
T
F
3. When the transmission shift lever is in a speed other than NEUTRAL, the rotary selector spool provides a path to drain for two clutches.
T
F
4. On all ICM transmission controls, the priority reduction valve controls the pressure of the "pilot oil" that is used to shift the selector piston in each station.
T
F
5. The load piston orifice in an ICM transmission is a "cascade-type" and controls the modulation of clutch engagement.
T
F
6. In an ICM transmission, the "primary pressure setting" in each station can cause harsh shifts when too low and clutch slipping when too high.
T
F
7. The "primary pressure settings" are the same for all ICM clutch stations.
T
F
8. Final clutch pressure is adjusted with shims.
T
F
9. If the "primary pressure setting" is correct and the final clutch pressure is low, the load piston springs should be replaced.
T
F
T
F
10. When manually rotating the rotary selector spool with the engine running, power to the shift solenoids must be disconnected.
Page:
III-45
Service Training MALAGA
777D Off Highway Truck Student book
SYSTEMS Adolfo August 1997
777D Off Highway Truck LOCKUP CLUTCH VALVE TORQUE CONVERTER DRIVE
LOAD PISTON
MODULATION REDUCTION VALVE
SELECTOR PISTON
LOAD PISTON ORIFICE PRESSURE REDUCTION VALVE
LOCKUP SOLENOID OFF
SHUTTLE VALVE
TO LOCKUP CLUTCH
FROM PARKING BRAKE PUMP
III. POWER TRAIN 1. 2. 3. 4.
Components Layout Operation Maintenance Testing & Adjusting Adolfo August 1997
777D Off Highway Truck CHAPTER : Power Train
TYPICAL OFF-HIGHWAY TRUCK POWER TRAIN COMPONENT LOCATIONS LOCKUP MODULATION VALVE
LOCKUP SOLENOID
TRANSMISSION PUMP TORQUE CONVERTER SOLENOIDS UPSHIFT DOWNSHIFT
TRANSMISSION
TRANSMISSION OIL FILTER
TORQUE CONVERTER FILTER
TORQUE CONVERTER AND TRANSMISSION OIL
INLET AND OUTLET RELIEF VALVES
TRANSMISSION
DRIVE SHAFT
TRANSMISSION CONTROL VALVE DIFFERENTIAL AND FINAL DRIVES
LOCKUP CLUTCH TORQUE CONVERTER
Page:
III-2
TORQUE TRANSFER CONVERTER GEARS PUMP
777D Off Highway Truck CHAPTER : Power Train
TORQUE CONVERTER CONVERTER DRIVE
TURBINE LOCKUP PISTON
TORQUE CONVERTER INLET OIL IMPELLER TORQUE CONVERTER LOCKUP OIL AGE
ENGINE FLYWHEEL
STATOR
FREEWHEEL ASSEMBLY
Page:
III-3
TO TRANSFER GEARS
777D Off Highway Truck CHAPTER : Power Train
TORQUE CONVERTER DIRECT DRIVE
TURBINE LOCKUP PISTON
TORQUE CONVERTER INLET OIL
IMPELLER
TORQUE CONVERTER LOCKUP OIL AGE
ENGINE FLYWHEEL
STATOR
FREEWHEEL ASSEMBLY
Page:
III-4
TOTRANSFER GEARS
Page: III-5
LOCKUP CLUTCH VALVE CLUTCH FILLING
LOAD PISTON
SELECTOR PISTON SHIMS
LOAD PISTON ORIFICE
LOCKUP SOLENOID ON
SHUTTLE VALVE
TO LOCKUP CLUTCH
FROM PARKING BRAKE PUMP
777D Off Highway Truck
PRESSURE REDUCTION VALVE
CHAPTER : Power Train
MODULATION REDUCTION VALVE
Page: III-6
LOCKUP CLUTCH VALVE DIRECT DRIVE
LOAD PISTON
SELECTOR PISTON
LOAD PISTON ORIFICE
LOCKUP SOLENOID ON
SHUTTLE VALVE
TO LOCKUP CLUTCH
FROM PARKING BRAKE PUMP
777D Off Highway Truck
PRESSURE REDUCTION VALVE
CHAPTER : Power Train
MODULATION REDUCTION VALVE
Page: III-7
769D - 777D TORQUE CONVERTER HYDRAULIC SYSTEM NEUTRAL
INLET RELIEF VALVE BRAKE COOLING PRESSURE
LOCKUP CLUTCH PILOT OIL PRESSURE
LOCKUP CLUTCH PRESSURE
LOCKUP MODULATION PARKING BRAKE VALVE RELIEF VALVE TO BRAKE COOLING CIRCUIT
OUTLET RELIEF VALVE
OUTLET PRESSURE TAP
INLET PRESSURE LOCKUP REDUCING VALVE
PARKING BRAKE RELEASE VALVE
CONVERTER CHARGING PUMP
PARKING BRAKE RELEASE PUMP
PARKING BRAKE RELEASE PRESSURE
LOCKUP CLUTCH
CONVERTER SCAVENGE PUMP SCREEN
TORQUE CONVERTER
SHIMS
777D Off Highway Truck
TO BRAKE COOLING CIRCUIT
CHAPTER : Power Train
LOCKUP SOLENOID
Page: III-8
769D - 777D TRANSMISSION HYDRAULIC SYSTEM NEUTRAL
DOWNSHIFT PRESSURE
UPSHIFT PRESSURE
A DOWNSHIFT UPSHIFT SOLENOID SOLENOID ROTARY ACTUATOR
FILTER
E
ON PUMP PRESSURE
B NEUTRALIZER VALVE
OIL COOLER
F ROTARY SELECTOR SPOOL
C
SCAVENGE PUMP
G
D
RELIEF VALVE
H
TRANSMISSION CASE
TANK
LUBE RELIEF VALVE
SELECTOR VALVE GROUP LUBE PRESSURE
PRESSURE CONTROL GROUP
777D Off Highway Truck
CHARGING PUMP
PRIORITY REDUCTION VALVE
CHAPTER : Power Train
PILOT OIL PRESSURE
777D Off Highway Truck CHAPTER : Power Train
769D - 777D TRANSMISSION SELECTOR VALVE GROUP NEUTRAL
NEUTRALIZER VALVE ROTARY SELECTOR SPOOL PRIORITY REDUCTION VALVE PILOT OIL PRESSURE SCREEN RELIEF VALVE
TRANSM. LUBE RELIEF VALVE
LUBRICATION PRESSURE
Page:
III-9
777D Off Highway Truck CHAPTER : Power Train
769C - 777C TRANSMISSION SELECTOR VALVE GROUP STARTING IN FIRST SPEED FORWARD
NEUTRALIZER VALVE
ROTARY SELECTOR SPOOL
PRIORITY REDUCTION VALVE
PILOT OIL PRESSURE SCREEN RELIEF VALVE
LUBE RELIEF VALVE
LUBRICATION PRESSURE
Page:
III-10
777D Off Highway Truck CHAPTER : Power Train
769D - 777D PRESSURE CONTROL GROUP NEUTRAL
A
E B
F
C
G D
H
Page:
III-11
Page: III-12
VALVE STATION CLUTCH RELEASED
SELECTOR PISTON SLUG
BALL CHECK VALVE
LOAD PISTON
PILOT OIL AGE
MODULATION REDUCTION VALVE FROM PUMP
LOAD PISTON PLUG
CLUTCH PRESSURE TAP TO CLUTCH
777D Off Highway Truck
DECAY ORIFICE LOAD PISTON ORIFICE
CHAPTER : Power Train
PLUG
777D Off Highway Truck CHAPTER : Power Train
VALVE STATION CLUTCH ENGAGED
Page:
III-13
777D Off Highway Truck CHAPTER : Power Train
VALVE STATION CLUTCH ENGAGED/WITH PIN
Page:
III-14
777D Off Highway Truck CHAPTER : Power Train
VALVE STATION CLUTCH DECAY
DECAY ORIFICE
Page:
III-15
Page: III-16
769C - 777C TRANSMISSION HYDRAULIC SYSTEM THIRD SPEED FORWARD
DOWNSHIFT PRESSURE
UPSHIFT PRESSURE
A DOWNSHIFT UPSHIFT SOLENOID SOLENOID ROTARY ACTUATOR
FILTER
E PUMP PRESSURE
B
OIL COOLER CHARGING PUMP
PRIORITY REDUCTION VALVE
F ROTARY SELECTOR SPOOL
C
SCAVENGE PUMP
G D RELIEF VALVE
H
TRANSMISSION CASE
TANK
LUBE RELIEF VALVE SELECTOR VALVE GROUP LUBE PRESSURE
PRESSURE CONTROL GROUP
777D Off Highway Truck
PILOT OIL PRESSURE
CHAPTER : Power Train
NEUTRALIZER VALVE
777D Off Highway Truck CHAPTER : Power Train
VALVE STATION PRIMARY PRESSURE
LOAD PISTON PLUG (REMOVED)
Page:
III-17
Page: III-18
777D SHIFT MODULATION CYCLE THIRD(3&6) TO FOURTH (1&5)
PRESSURE NORMAL SHIFT CYCLE CLUTCH 1 418
CLUTCH 5
CLUTCH 3
COMPLETE CLUTCH ENGAGEMENT
PRIMARY PRESSURE 50
INITIAL CLUTCH ENGAGEMENT
0 FILL TIME NORMAL CLUTCH SLIP
TIME
777D Off Highway Truck
265
CLUTCH 6
CHAPTER : Power Train
373 353
Page: III-19
777C SHIFT MODULATION CYCLE SECOND TO THIRD PRESSURE NORMAL SHIFT CYCLE
418 373
CLUTCH 3
COMPLETE CLUTCH ENGAGEMENT
80
PRIMARY PRESSURE
INITIAL CLUTCH ENGAGEMENT
0 FILL TIME NORMAL CLUTCH SLIP
TIME
777D Off Highway Truck
CLUTCH 1 265
CHAPTER : Power Train
CLUTCH 6
Page: III-20
PRESSURE HIGH PRIMARY PRESSURE
RESTRICTED LOAD PISTON ORIFICE SLOW MODULATION P1
COMPLETE CLUTCH ENGAGEMENT
0
TIME
HIGH PRIMARY PRESSURE - HARSH SHIFT NORMAL CLUTCH SLIP LOW PRIMARY PRESSURE - CLUTCH SLIPPING
SHIFT MODULATION PROBLEMS RESTRICTED LOAD PISTON ORIFICE CLUTCH SLIPPING
777D Off Highway Truck
NORMAL PRIMARY PRESSURE
CHAPTER : Power Train
LOW PRIMARY PRESSURE INITIAL CLUTCH ENGAGEMENT
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab A: Component Location and Identification Worksheet I 769D - 777D Off-highway Trucks Torque Converter Hydraulic System Directions: Refer to the Lab A Handout Illustration Worksheet V. Place the correct letter or number next to the component. During the slide presentation, use this sheet to take notes on the function of each component. ______ Torque Converter - example: Located on the rear of the engine. Provides a fluid coupling between the engine and the transmission and multiplies torque. Contains a lockup clutch for more efficient operation. ______ Torque Converter Pump (1. Scavenge, 2. Charging, and 3. Park Brake Release) -
______ Torque Converter Scavenge Screen -
______ Torque Converter Charging Filter -
______ Torque Converter Inlet Relief Valve -
______ Torque Converter Outlet Relief Valve -
______ Torque Converter Lockup Clutch Valve -
______ Parking Brake Release Valve -
______ Parking Brake Release Filter -
______ Lockup Clutch Solenoid Valve -
Page:
III-21
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab A: Component Location and Identification Worksheet ID 769D - 777D Off-highway Trucks Transmission Hydraulic System Directions: Refer to the Lab A Handout Illustration Worksheet V. Place the correct letter or number next to the component. During the slide presentation, use this sheet to take notes on the function of each component. ______ Transmission Tank - example: Located on the left side of the truck. Contains a sight gauge for checking power train hydraulic level. ______ Transmission Pump -
______ Transmission Filter -
______ Transmission Magnetic Suction Screen -
______ Transmission Oil Cooler -
______ Transmission Control Valve -
______ Upshift Solenoid Valve -
______ Downshift Solenoid Valve -
Page:
III-22
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab A: Component Location and Identification Worksheet V Torque Converter and Transmission Hydraulic Systems Component Identification
TYPICAL OFF-HIGHWAY TRUCK POWER TRAIN COMPONENT LOCATIONS
Page:
III-23
TO BRAKE COOLING CIRCUIT
TO BRAKE COOLING CIRCUIT
B. Parking Brake Release Pressure C. Lockup Clutch Pressure D. Outlet Pressure E. Pilot Pressure
Identify Components 1. Outlet Relief Valve
7. Inlet Relief Valve
2. Parking Brake Release Valve
8. Lockup Modulation Valve
3. Converter Charging Pump
9. Scavenge Pump
III-24
4. Torque Converter
10. Lockup Solenoid
5. Lockup Reducing Valve
11. Shuttle Valve
6. Parking Brake Release Pump
12. Lockup Clutch
777D Off Highway Truck
Page:
Directions: Write the letter or number of the item in the correct blank on the schematic.
A. Inlet Pressure
CHAPTER : Power Train
Worksheet I: (769D - 777D)
Identify Test Ports
LAB EXERCISES
Lab B: Torque Converter Hydraulic System Component Identification
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab C: Torque Converter Hydraulic System Testing Shop Lab Exercise Procedure: Perform the following tests listed in the Power Train Testing and Adjusting Service Manual Module for the lab machine used: • Visual Checks (8) for the hydraulic system which include Brake Cooling, Torque Converter, and Hoist Hydraulic Systems • Torque Converter Outlet Pressure • Torque Converter Inlet Pressure • Parking Brake Release Pressure • Lockup Clutch Pilot Pressure • Lockup Clutch Leakage • Lockup Clutch Signal Pressure (785B - 793B) • Lockup Clutch Maximum Pressure • Lockup Clutch Primary Pressure Class notes Lab D Worksheets (I and II) Off-highway Truck Mechanic's tools The following test equipment: 1 - 8T0854 Gauge 1000 kPa (145 psi) 1 - 8T0850 Gauge 4000 kPa (580 psi) 1 - 8T0851 Gauge 16000 kPa (2300 psi) 1 - 6V3965 Nipple 1 - 6V4143 Valved Coupler 1 - 6V3079 Diagnostic Hose 1 - 6V3121 Multitach Group 1 - Oil container [approximately 19 l (5 gal.) capacity] 1 - Special Instruction "6V3121 Multitach Group" (Form SEHS7807)
Page:
III-25
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab C: Torque Converter Hydraulic System Testing 769C - 777C Off-highway Trucks - Worksheet I Directions: Use this sheet to check off each of the steps listed in the Power Train Testing and Adjusting Service Manual Module. Machine Model______________________ Name/Code _________________________ Machine PIN (S/N)___________________ Transmission S/N ____________________ Engine S/N _________________________ S.M.H. ____________________________
Dealer ______________________________ Customer ___________________________ Job ________________________________ Application __________________________ Date _______________________________ Serviceman __________________________
VISUAL CHECKS ______ Check 1 - Oil levels in the hydraulic tank ______ Check 5 - Torque converter scavenge screen ______ Check 2 - External Leakage
______ Check 6 - Oil cooler screens
______ Check 3 - Parking brake release oil filter ______ Check 7 - Components inside hydraulic tank ______ Check 4 - Torque converter oil filter
TEST
______ Check 8 - Inspect return oil screen
SPECS
ACTUAL
Torque Converter Outlet Pressure at Stall Torque Converter Stall Speed Torque Converter Inlet Pressure Lockup Clutch Pilot Pressure Parking Brake Release Pressure Lockup Clutch Leakage Lockup Clutch Maximum Pressure Lockup Clutch Primary Pressure
Page:
III-26
Lab D: Tracing Torque Converter Oil System Flow (769D - 777D) Worksheet I Directions: Trace the flow of oil during the condition listed below using different colored pencils to show each path.
TO BRAKE COOLING CIRCUIT
III-27
777D Off Highway Truck
CHAPTER : Power Train
Page:
769D - 777D TORQUE CONVERTER HYDRAULIC SYSTEM TORQUE CONVERTER DRIVE
LAB EXERCISES
TO BRAKE COOLING CIRCUIT
Lab D: Tracing Torque Converter Oil System Flow (769D - 777D) Worksheet II Directions: Trace the flow of oil during the condition listed below using different colored pencils to show each path.
TO BRAKE COOLING CIRCUIT
TO BRAKE COOLING CIRCUIT
III-28
777D Off Highway Truck
CHAPTER : Power Train
LAB EXERCISES
Page:
769C - 777C TORQUE CONVERTER HYDRAULIC SYSTEM DIRECT DRIVE
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab E: Torque Converter Hydraulic System Operation (769D - 777D) Worksheet I Directions: Circle the letter of the correct statement that completes the sentence. Example: Torque converter leakage oil is removed from the torque converter by the: A. Parking brake release pump B. Scavenge pump C. Charging pump 1. The torque converter is in direct drive in the following speeds:
5. When the lockup solenoid opens and the shuttle valve moves, the shuttle valve:
A. REVERSE and FIRST
A. opens a age to drain
B. second half of FIRST through SEVENTH
B. closes a age to drain
C. NEUTRAL to FIRST
C. directs lockup clutch oil to the lockup clutch
2. If the torque converter lockup solenoid does not 6. Torque converter operating pressure is receive an electrical signal in SECOND SPEED maintained by the: FORWARD, the torque converter will: A. inlet relief valve A. stay in DIRECT DRIVE B. outlet relief valve B. go to DIRECT DRIVE C. parking brake release valve C. go to TORQUE CONVERTER DRIVE 7. Modulation of the lockup clutch is determined 3. The source of torque converter lockup oil is by the: from the: A. load piston A. transmission charging pump B. modulation reducing valve B. torque converter charging pump C. load piston orifice C. parking brake release pump 4. Excess oil pressure to the torque converter during a cold start-up is prevented by the _______. A. inlet relief valve B. outlet relief valve C. parking brake release valve
Page:
III-29
A E
ON
B F C G
Identify Test Ports
Identify Components
6. Priority Reduction Valve
12. Neutralizer valve
7. Main Relief Valve
13. Oil Cooler
B. Pump Pressure
2. Pressure Control Group
8. Scavenge Pump
14. Filter
C. Lube Pressure
3. Rotary Selector Spool
9. Downshift Solenoid
15. Screen
III-30
1. Charging Pump
Page:
A. Downshift Pressure
Worksheet I
Directions: Write the letter or D. Upshift Pressure number of the item in the correct blank on the schematic. E. Pilot Pressure
4. Upshift Solenoid
10. Rotary Actuator
5. Lube Relief Valve
11. Selector Valve Group
16. A to C and E to H
777D Off Highway Truck
Lab F: Transmission Hydraulic System Component Identification (769D - 777D)
CHAPTER : Power Train
H
LAB EXERCISES
D
VALVE STATION
Lab F: Transmission Hydraulic System Component Identification Pressure Control Group Valve Station Worksheet III Directions: Write the letter or number of the item in the correct blank on the schematic.
B. Pilot Pressure
7. Load Piston Orifice
9. Decay Orifice
3. Load Piston Plug 4. Pilot Oil age
10. Clutch Pressure Tap
III-31
8. Load Piston
Page:
2. Selector Piston
5. Pin
11. Slug
6. Pilot Oil Plug
12. Modulation Reduction Valve
777D Off Highway Truck
Identify Components Identify Test Ports 1. Ball Check Valve A. Primary and Clutch Pressures
CHAPTER : Power Train
TO CLUTCH
LAB EXERCISES
FROM PUMP
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab G: Transmission Hydraulic System Testing Shop Lab Exercise Procedures: Perform the following tests listed in the Power Train Testing and Adjusting Service Manual Module for the lab machine used: • Visual Checks (6) • Transmission Pump Pressure • Transmission Lubrication Pressure • Pilot Pressure • Pressure Control Group Clutch Pressures • Primary Clutch Pressures • Dual Stage Relief Valve Pressure Class notes Lab G Worksheets (I and II) Off-highway Truck Mechanic's tools The following test equipment: 1 - 1U5481 Pressure Gauge Group 1 - 1U5482 Pressure Adaptor Group 1 - 3B7282 Nipple 1 - 3B6552 Nipple 1 - 6V4142 Unvalved Nipple 1 - 6V6064 or FT1775 Transmission Test Cover
Page:
III-32
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab G: Transmission Hydraulic System Testing 769D - 793C Off-highway Trucks - Worksheet I Directions: Use this sheet to check off each of the steps listed in the Power Train Testing and Adjusting Service Manual Module. All tests should be run with the transmission in NEUTRAL. Machine Model______________________ Name/Code _________________________ Machine PIN (S/N)___________________ Transmission S/N ____________________ Engine S/N _________________________ S.M.H. ____________________________
Dealer ______________________________ Customer ___________________________ Job ________________________________ Application __________________________ Date _______________________________ Serviceman __________________________
VISUAL CHECKS ______ Check 1 - Oil levels in the hydraulic tank ______ Check 5 - Transmission case oil quantity ______ Check 2 - External leakage
______ Check 6 - Transmission oil tank debris
______ Check 3 - Oil filter examination ______ Check 4 - Magnetic screen debris DU AL S TAGE RELIEF
LOCKU P CLU TCH DEACTIVATED S PECS LOW IDLE
HIGH IDLE
ACTU AL LOW IDLE
HIGH IDLE
PU MP PRES S U RE DU AL S TAGE RELIEF
LOCKU P CLU TCH ACTIVATED S PECS LOW IDLE
HIGH IDLE
ACTU AL LOW IDLE
HIGH IDLE
PU MP PRES S U RE S PECS LOW IDLE PILOT PRES S U RE
HIGH IDLE NO
ACTU AL LOW IDLE
HIGH IDLE NO
LU BE PRES S U RE
Page:
III-33
777D Off Highway Truck CHAPTER : Power Train
LAB EXERCISES Lab G: Transmission Hydraulic System Testing 769D - 793C Off-highway Trucks - Worksheet II Directions: Use this sheet to check off each of the steps listed in the Power Train Testing and Adjusting Service Manual Module.
CLU TCH CHART N
PRIMARY CLU TCH PRES S U RE AT LOW IDLE (LOAD PIS TON PLU G REMOVED) STATION CLUTCH SPECS ACTUAL
R
A
1
B
2
C
3
D
4
E
5
F
6
G
7
H
PRIMARY CLU TCH PRES S U RE AT LOW IDLE (LOAD PIS TON PLU G IN S TALLED) S PECS ACTU AL S TATION
CLU TCH
LOW IDLE
HIGH IDLE
LOW IDLE
HIGH IDLE
A B C D E F G H
Page:
III-34
777D Off Highway Truck CHAPTER : Power Train
POSTTEST As this component moves and closes a drain age, modulation will begin
1. Load Piston 2. Pilot Oil age
Removal of this component allows the technician to check pilot pressure Allows oil from the rotary selector spool to move the selector piston Controls the rate of clutch engagement Works with the modulation reduction valve to control clutch pressure
3. Decay Orifice 4. Load Piston Plug 5. Modulation Reduction Valve 6. Load Piston Orifice 7. Ball Check Valve
Allows clutch pressure to be directed into the center chamber of the modulation reduction valve
8. Clutch Pressure Tap
Allows the technician to check clutch pressure
9. Pilot Pressure Plug
Removal of this component causes the clutch pressure to remain at the primary pressure
10. Selector Piston 11. Slug
Controls the rate of clutch release Works with load piston to control clutch pressure Directions: Modified True/False. If a statement is false, underline or circle the word or words that make the statement incorrect and replace with word(s) to make the statement correct. (Each question is worth 2 points.) a transmission Example: F 1. This is an engine class. 1. To initiate clutch filling, pilot oil moves the selector piston. 2. The size of the modulation reducing valve determines the rate of clutch modulation. 3. To check the primary clutch pressure, remove the load piston plug. 4. Pins in a clutch station increase the modulation time. 5. Clutch release time is determined by the decay orifice.
Page:
III-35
Directions: Match the components and test ports with the associated number or letter. (Each question is worth 1 point.)
13
Test Ports
1
Primary Pressure
VALVE STATION
15
14
Pilot Pressure
10
Clutch Pressure
11
Components
Load Piston Plug
9
Modulation Reduction Valve Load Piston Orifice Ball Check Valve Clutch Pressure Tap Page:
Pilot Oil Plug Selector Piston
III-36
Slug Pin
2
6 5 FROM PUMP
4 TO CLUTCH
3 8
12
777D Off Highway Truck
Decay Orifice
CHAPTER : Power Train
7
Pilot Oil age
POSTTEST
Load Piston
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Directions: Use the schematic on page 38. After each statement, circle the correct sequence of events that occurs. Example: The operator makes a shift from NEUTRAL to FIRST FORWARD. C. 1-Modulation begins A. 1-Pilot oil moves B. 1-Selector piston closes selector piston drain 2-Load piston moves reducing valve 2-Selector piston closes 2-Pilot oil moves drain selector piston 3-Selector piston closes drain 3-Load piston moves 3-Modulation begins reducing valve 4-Pilot oil moves 4-Load piston moves selector piston 4-Modulation begins reducing valve
A. 1-Rotary selector spool opens pilot oil age to drain 2-Load piston oil is directed through decay orifice 3-Selector piston opens drain
A. 1-Pump oil is directed through load piston orifice 2-Pump oil is directed to clutch 3-Modulation reduction valve moves
B. 1-Rotary selector spool opens pilot oil age to drain
C. 1-Selector piston opens drain
2-Selector piston opens drain
2-Load piston oil is directed through decay orifice
3-Load piston oil is directed through decay orifice
3-Rotary selector spool opens pilot oil age to drain
B. 1-Pump oil is directed to clutch
C. 1-Modulation reduction valve moves
2-Modulation reduction valve moves
2-Pump oil is directed to clutch
3-Pump oil is directed through load piston orifice
3-Pump oil is directed through load piston orifice
Page:
III-37
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Torque Converter Hydraulic System Posttest (769D - 777D) Directions: Match the component to its primary function. Maintains high oil pressure to the lockup reducing valve
1. Lockup Solenoid
Supplies oil for hydraulic energy transfer
2. Inlet Relief Valve
Maintains working pressure within the torque converter
3. Torque Converter
When energized, supplies pilot oil to initiate direct drive
4. Lockup Reducing Valve
Relieves excess pressure to the torque converter
5. Parking Brake Release Valve
Provides a controlled rate of engagement of the lockup clutch
6. Outlet Relief Valve
Transfers engine power to the transmission
7. Lockup Modulation Valve
Reduces pump supply pressure to pilot pressure
8. Converter Charging Pump
Supplies oil to the lockup clutch
9. Diverter Valve 10. Parking Brake Release Pump
Directions: Modified True/False. If a statement is false, underline or circle the word or words that make the statement incorrect and replace with word(s) to make the statement correct. a power train Example: F 1. This is an engine class. 1. The inlet relief valve controls the maximum pressure in the torque converter. 2. The parking brake release pump supplies oil to the lockup modulation valve. 3. Lockup clutch oil pressure is controlled by the parking brake release valve. 4. Transmission oil pressure is used to pressurize the torque converter lockup clutch when the torque converter is in direct drive. 5. When the transmission is in REVERSE, the torque converter is in direct drive. 6. Direct drive is in gears FIRST through SEVENTH.
Page:
III-38
Directions: Match the components and test ports with the associated number or letter.
Test Ports Parking Brake Release Pressure Pilot Pressure E
Outlet Pressure Inlet Pressure
1
TO BRAKE COOLING CIRCUIT
Lockup Clutch Pressure
7 10
TO BRAKE COOLING CIRCUIT
A 5
Components
Parking Brake Release Valve
2
12 6 B 3
Outlet Relief Valve Lockup Modulation Valve Converter Charging Pump Page:
Scavenge Pump
III-39
Parking Brake Release Pump Shuttle Valve
9
769D - 777D TORQUE CONVERTER HYDRAULIC SYSTEM
777D Off Highway Truck
11
Torque Converter
CHAPTER : Power Train
Inlet Relief Valve
POSTTEST
4
Lockup Solenoid
Lockup Reducing Valve
D
C
8
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Directions: Use the schematic on page 41. After each statement, circle the correct sequence of events that occurs. Example: The operator makes a shift from NEUTRAL to FIRST FORWARD and the ground speed increases. A. 1-Torque converter is in TC drive 2-Ground speed increases and the lockup clutch modulation valve is activated 3-Lockup clutch engages
A. 1-Parking brake release oil directed to lockup modulation valve spool 2-Pilot oil directed to lockup solenoid valve 3-Parking brake release pump directs oil to lockup reducing valve
A. 1-Shuttle valve moves and blocks drain 2-Load piston moves 3-Lockup solenoid valve opens
A. 1-Shuttle valve moves and opens drain 2-Lockup solenoid valve closes 3-Load piston moves
B. 1-Lockup clutch engages 2-Ground speed increases and the lockup clutch modulation valve is activated 3-Torque converter is in TC drive
B. 1-Parking brake release oil directed to lockup modulation valve spool 2-Parking brake release pump directs oil to lockup reducing valve 3-Pilot oil directed to lockup solenoid valve
B. 1-Lockup solenoid valve opens 2-Shuttle valve moves and blocks drain 3-Load piston moves
B. 1-Load piston moves 2-Shuttle valve moves and opens drain 3-Lockup solenoid valve closes
C. 1-Ground speed increases and the lockup clutch modulation valve is activated 2-Lockup clutch engages 3-Torque converter is in TC drive
C. 1-Parking brake release pump directs oil to lockup reducing valve 2-Pilot oil directed to lockup solenoid valve 3-Parking brake release oil directed to lockup modulation valve spool
C. 1-Load piston moves 2-Lockup solenoid valve opens 3-Shuttle valve moves and blocks drain
C. 1-Lockup solenoid valve closes 2-Shuttle valve moves and opens drain 3-Load piston moves
Page:
III-40
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Directions: Match the component to its primary function.
Regulates pressure inside oil cooler Reduces temperature of transmission oil Removes oil from transmission case
1. Charging Pump 2. Pressure Control Group 3. Rotary Selector Spool 4. Upshift Solenoid
Maintains pilot oil pressure Removes debris from transmission oil Supplies modulated pressures to clutches
5. Oil Cooler Relief Valve 6. Priority Reduction Valve 7. Main Relief Valve 8. Scavenge Pump
Directs oil to move rotary actuator vane clockwise Maintains maximum system pressure Chooses appropriate clutch combinations for each speed
9. Downshift Solenoid 10. Rotary Actuator 11. Selector Valve Group 12. Neutralizer Valve
Six valve clutch stations Moves rotary selector spool Keeps machine from moving if transmission is started in gear
13. Oil Cooler 14. Filter 15. Manifold 16. A through H
Supplies oil to all clutches Directs oil to move rotary actuator vane counterclockwise Maintains and directs oil pressures to the pressure control group
Page:
III-41
777D Off Highway Truck CHAPTER : Power Train
POSTTEST Directions: Modified True/False. If a statement is false, underline or circle the word or words that make the statement incorrect and replace with word(s) to make the statement correct. a transmission Example: F 1. This is an electrical test. 1. In NEUTRAL, no clutches are engaged. 2. If the machine is started IN GEAR, the neutralizer valve stops the flow of pilot oil. 3. Clutch pressure is maintained by the relief valve. 4. Reverse is an upshift. 5. During a shift, clutches are always drained and then refilled. 6. REVERSE and the first half of FIRST are torque converter drive.
Page:
III-42
Test Ports Pump Pressure
Directions: Match the components and test ports with the associated number or letter.
Upshift Pressure Downshift Pressure Pilot Pressure Lube Pressure Components Scavenge Pump Priority Reduction Valve
D
A
A
Rotary Selector Spool
9
4
14
Neutralizer Valve
12
Pressure Control Group Main Relief Valve
1
6
E 13
F 3
C
8 G
Charging Pump D
7
Downshift Solenoid
H
Filter Selector Valve Group Page:
Upshift Solenoid
15
16
5 11 C
Oil Cooler Rotary Actuator
III-43
Screen
769D- 777D TRANSMISSION HYDRAULIC SYSTEM
2
777D Off Highway Truck
A to C and E to H
CHAPTER : Power Train
B
POSTTEST
B
Lube Relief Valve
E
10
ON
777D Off Highway Truck CHAPTER : Power Train Directions: Use the schematic on page 45. After each statement, circle the correct sequence of events that occurs. Example: The operator has moved the shift lever from NEUTRAL to FIRST FORWARD. A. 1-Downshift solenoid is de-energized 2-Upshift solenoid is energized
B. 1-Rotary actuator moves to FIRST SPEED FORWARD
3-Rotary actuator moves to FIRST SPEED FORWARD
C. 1-Upshift solenoid is energized
2-Downshift solenoid is de-energized
2-Rotary actuator moves to FIRST SPEED FORWARD
3-Upshift solenoid is energized
3-Downshift solenoid is de-energized
1. The engine is started with the transmission in NEUTRAL. A. 1-Neutralizer valve moves 2-Pilot oil flows through rotary selector spool to one station
B. 1-Pilot oil flows through rotary selector spool to one station 2-Downshift solenoid is energized
3-Downshift solenoid is energized
3-Neutralizer valve moves
C. 1-Downshift solenoid is energized 2-Neutralizer valve moves 3-Pilot oil flows through rotary selector spool to one station
2. The engine is started with the gear shift lever in FIRST SPEED FORWARD. A. 1-Charge pump oil flows to priority reduction valve
B. 1-Rotary selector spool blocks charge pump oil to neutralizer valve
C. 1-Pilot oil flows to neutralizer valve
2-Pilot oil flows to neutralizer valve
2-Pilot oil flows to neutralizer valve
2-Rotary selector spool blocks charge pump oil to neutralizer valve
3-Rotary selector spool blocks charge pump oil to neutralizer valve
3-Charge pump oil flows to priority reduction valve
3-Charge pump oil flows to priority reduction valve
3. During an upshift, the following occurs: A. 1-Charge pump moves the upshift valve 2-Upshift solenoid is energized 3-Rotary actuator oil moves the downshift valve
B. 1-Upshift solenoid is energized 2-Charge pump oil moves the rotary actuator 3-Rotary actuator moves the rotary selector spool
C. 1-Rotary actuator oil moves the downshift valve 2-Upshift solenoid is energized 3-Charge pump moves the upshift valve
Page:
III-44
777D Off Highway Truck CHAPTER : Power Train Directions: After each statement, circle T if the statement is TRUE, and F if the statement is FALSE. Example: When activated, the shift solenoids allow oil to flow to the rotary actuator.
T
F
1. On some ICM transmissions, the Dual Stage Relief Valve is activated during torque converter lockup.
T
F
2. On all ICM transmission controls, REVERSE is an upshift from NEUTRAL and the downshift solenoid is activated whenever the shift lever is in NEUTRAL.
T
F
3. When the transmission shift lever is in a speed other than NEUTRAL, the rotary selector spool provides a path to drain for two clutches.
T
F
4. On all ICM transmission controls, the priority reduction valve controls the pressure of the "pilot oil" that is used to shift the selector piston in each station.
T
F
5. The load piston orifice in an ICM transmission is a "cascade-type" and controls the modulation of clutch engagement.
T
F
6. In an ICM transmission, the "primary pressure setting" in each station can cause harsh shifts when too low and clutch slipping when too high.
T
F
7. The "primary pressure settings" are the same for all ICM clutch stations.
T
F
8. Final clutch pressure is adjusted with shims.
T
F
9. If the "primary pressure setting" is correct and the final clutch pressure is low, the load piston springs should be replaced.
T
F
T
F
10. When manually rotating the rotary selector spool with the engine running, power to the shift solenoids must be disconnected.
Page:
III-45
Service Training MALAGA
777D Off Highway Truck Student book
SYSTEMS Adolfo August 1997
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