769D-771D-773D-775D.PDF

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TECHNICAL PRESENTATION

769D/771D/773D/775D

UPDATE

OFF-HIGHWAY TRUCKS

PRELIMINARY INFORMATION

This document is provided for your reference only.

It may not be reproduced for use by others without

the authorization of East Peoria Service Training.

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769D--36.8 Metric tons (40.6 tons) @ 68182 kg (150,000 lbs.) GMW 771D--40.0 Metric tons (44.1 tons) @ 73970 kg (163,100 lbs.) GMW 773D--52.3 Metric tons (57.7 tons) @ 92530 kg (204,000 lbs.) GMW 775D--62.6 Metric tons (69.1 tons) @ 106594 kg (235,000 lbs.) GMW Shown is the left side of a 775D update truck. The fuel tank is located on the left side of the truck. On D-series pre-update trucks, the fuel tank is located on the right side of the truck.

¥ Fuel tank ¥ Load carrying

capacity

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2

Shown is the right side of a 775D update truck. The service and retarder air tanks, the brake master cylinders, the relay valves and the brake oil makeup tank are located on the right platform near the steering tank and the engine air filters.

The main hydraulic tank is also visible. The hydraulic tank supplies oil for the hoist system and the brake system.

On the D-series pre-update trucks, torque converter oil is also supplied from the main hydraulic tank. A transmission oil supply tank is located in front of the main hydraulic tank.

The D-series update trucks now use the torque converter case as the supply tank for the torque converter and the transmission.

¥ Brake system components located on right platform

¥ Torque converter case used as sump for converter and transmission

¥ Main hydraulic tank: - Hoist system - Brake system

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775D update truck

3

Shown is the front of a 775D update truck. The 773D and 775D update trucks use a conventional radiator core. All other Caterpillar Off-highway Trucks use a folded-core style radiator.

The folded-core style radiator provides the convenience of repairing or replacing smaller individual cores. The conventional radiator core requires repair or replacement of a large single core.

¥ Radiator cores - folded-core - conventional core

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¥ Truck body options: - 12 degree flat floor - Dual-slope

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Shown is the rear of a 775D update truck. Two body options are available for the D-series update trucks:

- A 12 degree flat floor design that provides uniform load dumping, excellent load retention and a low center of gravity.

- A dual-slope design with a "V" bottom main floor to reduce shock loading, center the load and reduce spills.

All internal wear surfaces of the truck bodies are made with 400 Brinell hardness steel. All attachment body liners are also made with 400 Brinell hardness steel. The external components of the bodies are made of steel with a yield strength of 6205 bar (90000 psi).

The rear suspension cylinders absorb bending and twisting stresses rather than transmitting them to the main frame.

¥ Rear suspension cylinders

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5 FUEL TANK ENGINE OIL HOIST AND BRAKE OIL TRANSMISSION AND TORQUE CONVERTER OIL MAINTENANCE 10 HOURS/DAILY STEERING OIL RADIATOR AIR RESERVOIR SEAT BELTS

SECONDARY STEERING TEST BRAKE TESTS INDICATORS AND GAUGES

BACKUP ALARM TEST

SUSPENSION CYLINDERS

SUSPENSION CYLINDERS

AIR RESERVOIRS AIR FILTERS AND

PRECLEANERS BATTERIES

PRIMARY FUEL FILTER/ WATER SEPARATOR DISCONNECT SWITCH

775D

WALK-AROUND INSPECTION

The following list identifies the items that must be serviced every 10 Hours or Daily.

- Walk-Around Inspection: Check for loose or missing bolts, leaks and cracks in frame structures

- Suspension cylinders: Measure/recharge

- Primary fuel filter/water separator: Drain moisture - Transmission and torque converter oil: Check level - Hoist and brake cooling oil: Check level

- Fuel tank: Drain moisture

- Radiator: Check level and radiator core plugging - Steering system oil: Check level

- Air reservoirs: Drain moisture - Engine crankcase oil: Check level - Brakes: Check operation

- Indicators and gauges: Test operation - Seat belt: Inspect

- Back-up alarm: Test operation - Secondary steering: Test operation

¥ Maintenance - 10 hours/daily

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6

2

1

Supply oil for the transmission and the torque converter is contained in the torque converter case. Sight gauges (1) are used to check the oil level for the transmission and the torque converter.

Transmission and torque converter oil is added at the fill tube (2). When filling the transmission and torque converter oil sump after an oil change, fill the sump with oil to the top of the upper sight gauge. Crank the engine for approximately 15 seconds. The oil level will decrease as oil fills the transmission and torque converter system. If the engine starts, do not allow it to run for more than 15 seconds. Add more oil to the sump to raise the oil level to the FULL COLD mark. Crank the engine for an additional 15 seconds. Repeat this step as required until the oil level stabilizes.

Start the engine and warm the transmission and torque converter oil. Add more oil to the sump as required to raise the transmission and torque converter oil level to the FULL WARM mark with the engine running.

NOTICE

Failure to correctly fill the transmission and torque converter oil sump after an oil change may cause transmission clutch damage.

1. Transmission and torque converter oil level sight gauges

2. Transmission and torque converter oil fill tube

¥ Transmission and torque converter oil fill procedure

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Use only Transmission Drive Train Oil (TDTO) with a specification of (TO-4) or newer.

- TDTO TO-4 provides maximum frictional capability required for clutch discs used in transmissions and torque converters.

- Increases rimpull because of reduced slippage.

- Use only mono-viscosity (straight weight) oils. Multi-viscosity oils use viscosity improvers which, when subjected to shearing

situations, are reduced to the lower weight rating. For example, when a 10W-30 oil is used in a sheer condition, after time the oil will only perform to 10W specifications.

- Never use engine oil in transmissions. Engine oils are formulated to minimize friction. Oils used in transmissions and torque converters must allow adequate friction to reduce slippage.

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¥ Hoist and brake hydraulic tank

1. Oil level sight gauge door 7 1 2 4 3

Shown is the hoist and brake hydraulic tank. The oil level is checked by opening the small door (1) and looking through the sight gauge The oil level should first be checked with cold oil and the engine stopped. The level should again be checked with warm oil and the engine running. Use only Transmission Drive Train Oil (TDTO) with a specification of (TO-4) or newer.

- TDTO TO-4 provides maximum frictional capability required for clutch discs used in the brakes.

- Increases brake holding capability by reducing brake slippage. - Controls brake chatter.

Check the hoist and brake hydraulic tank breather (2) for plugging (cover removed for visibility). Clean the filter if plugged. If oil is flowing from the filter, the hoist and brake hydraulic tank may be overfilled.

Hoist and brake cooling oil returns to the hydraulic tank through a screen located below cover (3).

The diverter (towing) valve (4) is used when it is necessary to release the parking brakes for towing with a dead engine. The towing valve will be discussed in more detail in the Air System and Brakes section of this meeting guide.

¥ Use only TDTO oil

2. Breather

3. Return screen cover

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¥ Fuel tank

8

2

1

The fuel tank is located on the left side of the truck. The fuel level sight gauge (1) is used to check the fuel level during the walk around

inspection.

A fuel level sender is located on the fuel level sight gauge. The fuel level sender provides input signals to the Caterpillar Monitoring System or the attachment Vital Information Management System (VIMS) which informs the operator of the fuel level.

The percentage of sulfur in the fuel will affect the engine oil

recommendations. The following is a summary of fuel sulfur and oil recommendations:

1. Use API CG-4 performance oils.

2. With fuel sulfur below 0.5%, any API CG-4 oils will have a sufficient Total Base Number (TBN) for acid neutralization. 3. For fuel sulfur values above 0.5%, the new oil TBN should be a

minimum of 10 times the fuel sulfur.

4. When 10 times the fuel sulfur exceeds the oil TBN, reduce the oil change interval to about 1/2 the normal change interval.

Open the drain valve (2) to remove condensation from the fuel tank.

1. Fuel level sight gauge

¥ Fuel level sender

¥ Fuel information

2. Condensation drain valve

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9 2 4 5 3 1

Shown is the location of the parking brake retraction filters (1). Oil flows from the parking brake retraction pump through the parking brake

retraction filters to the parking brake retraction valve. Oil flows from the parking brake retraction valve to the parking brake piston in the rear brakes when the parking brakes are released.

Parking brake retraction supply oil also flows to the hoist control valve and is used as pilot oil to shift the hoist directional spool.

Hoist and brake oil samples can be taken at the Scheduled Oil Sampling (S¥O¥S) tap (2).

Located to the right of the parking brake retraction filters are the transmission and torque converter filters (3). Oil flows from the transmission and torque converter charging pump through the transmission and torque converter filters to the transmission control valves on top of the transmission and to the torque converter lockup clutch valve located on top of the torque converter.

Transmission and torque converter oil samples can be taken at the Scheduled Oil Sampling (S¥O¥S) tap (4).

A transmission and torque converter filter bypass switch (5) is located on the filter base. The bypass switch provides input signals to the Caterpillar Monitoring System or the VIMS which informs the operator if the

transmission and torque converter filters are restricted.

1. Parking brake retraction filters 3. Transmission and torque converter filters 4. Transmission/TC S¥O¥S tap 5. Transmission/TC filter bypass switch 2. Hoist and brake oil

S¥O¥S tap ¥ Parking brake

retraction oil used as hoist pilot oil

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10

1

3

2

Shown is a 775D update truck with the arctic attachment installed. Trucks with the arctic attachment have a second set of batteries located under the battery cover (1).

To make room for the additional batteries, the air filter housings are installed vertically and there are no precleaners. Two filter elements are installed in the filter housings. The large element is the primary

element (2) and the small element is the secondary element (3).

¥ No precleaners with arctic attachment 2. Primary element 3. Secondary element 1. Arctic battery cover

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11 5 2 1 4 3

Located behind the air filters is the steering system tank. Check the steering system oil level at the sight gauge (1).

The steering system oil filter (2) is located on the side of the steering tank. Steering system oil samples can be taken from the Scheduled Oil

Sampling (S¥O¥S) tap (3) located on top of the steering filter.

The steering system uses a pressure compensated piston type pump. Case drain oil from the steering pump returns to the hydraulic tank through a screen that is part of the fitting (4) installed in the side of the steering tank.

Before removing the cap to add oil to the steering system, depress the pressure release button (5) on the breather to release any remaining pressure from the tank.

¥ Steering system tank 1. Steering system oil

level sight gauge 2. Steering system oil

filter

3. Steering system S¥O¥S tap

4. Case drain oil filter screen fitting

5. Steering tank pressure release button and breather

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12

3

1 2

4

Located near the air filters and the steering tank are the front and rear brake cylinders (1) and the brake oil makeup tank (2).

Inspect the condition of the breathers (3) for the brake cylinders. Oil should not leak from the breathers. Oil leaking from the breathers is an indication that the oil piston seals in the brake cylinder need replacement. Air flow from the breathers during a brake application is an indication that the brake cylinder air piston seals need replacement.

If air is in the system or a loss of oil downstream from the cylinders occurs, the piston in the cylinder will overstroke and cause an indicator rod to extend and open the brake overstroke switch (4). The switch provides an input signal to the Caterpillar Monitoring System or the VIMS which informs the operator of the condition of the service/retarder brake oil circuit. If an overstroke condition occurs, the problem must be repaired and the indicator rod pushed in to end the warning.

1. Brake master cylinders

2. Brake oil makeup tank

3. Brake cylinder breather

4. Brake overstroke switch

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1. Service/retarder brake tanks 2. Service/retarder

brake tank drain valve

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3

1 ₂

The service and retarder brake air tanks (1) are located behind the brake cylinders and the brake oil makeup tank. Drain condensation from the tanks daily with the drain valve (2).

Located above the service and retarder brake air tanks are the brake relay valves (3), a double check valve and the inversion valve.

3. Brake relay valves ¥ Double check valve ¥ Inversion valve

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The remaining 10 Hours or Daily checks are performed in the operator's compartment. They are as follows:

- Brakes: Check operation

- Indicators and gauges: Test operation - Seat belt: Inspect

- Back-up alarm: Test operation - Secondary steering: Test operation

The brakes are checked by engaging one of the brake systems and placing the shift lever in FIRST FORWARD. Accelerate the engine until the truck moves. The truck must not move below 1200 rpm. This procedure should be repeated for each brake lever or pedal.

See the Operation and Maintenance Manual for more information on the remaining tests performed in the cab.

¥ 10 hours/daily checks performed in the operator's cab

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The blue service lamp (arrow) located on the left side of the cab is part of the attachment Vital Information Management System (VIMS). When the key start switch is turned to the ON position, The VIMS runs through a self test. During the self test the service lamp will flash three times if there are logged events stored in the VIMS main module and once if there are no logged events.

During normal operation, the service lamp will turn ON to notify service personnel that the VIMS has an active machine or system event. The service lamp flashes to indicate when an event is considered abusive to the machine.

INSTRUCTOR NOTE: For more detailed information on the VIMS, refer to the Service Manual Module "Vital Information Management System (VIMS)" (Form SENR6059).

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16 ENGINE TEMP [135] 60 Deg F ID OK - TRACTION ASSIST - RETARDING - OVERSPEED RETARDING - RETARDING LAMP

INTEGRATED BRAKE CONTROL (IBC)

3F 12MPH

km/h

SERVICE TOOL

CATERPILLAR MONITORING SYSTEM OR VITAL INFORMATION MANAGEMENT SYSTEM (VIMS)

SPI LINK - GAUGES - MONITORING - WARNINGS - CLOCK SYCHONIZATION - MACHINE ID ADEM II - EMISSIONS CONTROL - FUEL INJECTION - ETHER INJECTION - FAN CONTROL - ENGINE PRE-LUBE - ICM CONTROL - NEUTRAL START - BACKUP ALARM - OVERSPEED PROTECTION - CTS - ENGINE PRE-LUBE

- DIRECTIONAL SHIFT MANAGEMENT - AUTOLUBE

- TOP GEAR LIMIT - REVERSE NEUTRALIZE - LOAD COUNTER - NEUTRAL COAST INHIBIT - BODY UP GEAR LIMIT - STARTER PROTECTION - BODY HOIST CONTROL - SECONDARY STEERING - SPEED LIMITER

EPTC III CAT DATA LINK

- GAUGES - MONITORING - WARNINGS - CLOCK SYCHONIZATION - MACHINE ID - TELEMETRY - PAYLOAD MEASUREMENT - STRUT DIAGNOSTICS VIMS DISPLAY MODULES VIMS MAIN MODULE 769D/771D/773D/775D UPDATE OFF-HIGHWAY TRUCKS INTERFACE MODULES OPERATORÕS STATION Caterpillar Monitoring System

The Caterpillar Monitoring System is the standard monitoring system installed on the D-series update Off-highway Trucks. The Caterpillar Monitoring System is a flexible, modular monitoring system that includes: a message center module, various switches and sensors, an action lamp and action alarm.

The "heart" of the system is the message center module where information is received from switches and sensors over the CAT Data Link and

processed. The message center module then activates various outputs.

The Vital Information Management System (VIMS) is being tested as a possible future attachment on the D-series update trucks.

If a truck is equipped with the VIMS, the message center control module of the Caterpillar Monitoring System is replaced with the VIMS message center module, a keypad module, a VIMS main module and two interface modules.

¥ Caterpillar Monitoring System is standard

¥ VIMS is possible future option

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¥ Middle front dash panel

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Shown is the middle of the front dash panel. Nine dash indicators, the four-gauge cluster module and the speedometer/tachometer module are shown.

The four dash indicators to the left of the four-gauge cluster module are (from top to bottom):

¥ Left Turn

¥ Body Up--Lights when the body is up. Input is from the Body Up switch.

¥ Reverse--Lights when the shift lever switch is in REVERSE.

¥ High Beam

¥ Left dash indicators (top to bottom) - Left turn - Body up - Reverse - High Beam

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The five dash indicators to the right of the Speedometer/Tachometer Module are (from top to bottom):

¥ Right Turn

¥ Action Lamp--Lights when a Category 2 or Category 3 warning is active.

¥ Secondary Steering--Lights when the secondary steering pump is ON.

¥ Retarder--Lights when the retarder is ENGAGED (Auto or Manual).

¥ TCS--Lights when the Traction Control System (TCS) is ENGAGED.

The four systems monitored by the Four-Gauge Cluster Module are (top then bottom left to right):

¥ Engine Coolant Temperature--Maximum operating temperature: 107 ¡C (225 ¡F)

¥ Brake Oil Temperature--Maximum operating temperature: 121 ¡C (250 ¡F)

¥ System Air Pressure--Minimum operating pressure:

483 kPa (70 psi) on trucks with the Caterpillar Monitoring System. 450 kPa (65 psi) on trucks with the VIMS.

¥ Fuel Level--Minimum operating level:

8% on trucks with the Caterpillar Monitoring System.

On trucks with the VIMS there are two fuel level warning Categories:

- 10%--Category 1 - 5%--Category 2

¥ Right dash indicators (top to bottom) - Right turn - Action lamp - Secondary steering - Retarder - TCS ¥ Four-gauge cluster module: - Engine coolant temperature - Brake oil temperature

- System air pressure - Fuel level

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To the right of the Speedometer/Tachometer Module are several rocker switches. The rocker switches control the following systems:

Top row (from left to right)

¥ Lights

¥ Vacant

¥ ARC--Turns on the Automatic Retarder Control (ARC) system. ¥ TCS Test--Tests the Traction Control System (TCS). Use this switch

when turning in a tight circle with the engine at low idle and the transmission in FIRST GEAR.

¥ Caterpillar Monitoring System Operator Scroll--Allows the Operator to scroll through the Operator Modes in the Message Center Module display window.

¥ Rocker switches (top row): - Lights - Automatic retarder control - Traction control system test - Operator modes scroll

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Bottom row (from left to right)

¥ Throttle Backup/Throttle Lock: (customer installed option) - Throttle Backup--Raises the engine speed to 1300 rpm if the

throttle sensor signal is invalid.

- Throttle Lock--If the transmission is in NEUTRAL and the parking brake is ENGAGED, the throttle lock will hold any

current engine rpm selected by the operator. If any service/retarder brake is ENGAGED, the engine rpm will return to LOW IDLE. After a brake application, the throttle lock must be turned OFF to reset the system before the throttle lock function will work again.

¥ Ether Starting Aid--Allows the Operator to manually inject ether if the engine oil temperature is below 10 ¡C (50 ¡F) and engine speed is below 1200 rpm (customer installed option).

¥ Air Conditioning

¥ Body Up Sound Reduction--Reduces engine HIGH IDLE to 1800 rpm when the body is raised.

¥ Secondary Steering and Brake Retraction--Normally when this switch is depressed, the steering system receives secondary steering oil flow and brake retraction oil flows to tank. When the brake retraction diverter (towing) valve spool is shifted, this switch will also release the parking brakes (see Slide No. 71).

NOTE: The Secondary Steering and Brake Retraction switch can also be used to provide hoist pilot oil for lowering the body on trucks with a dead engine (see Slide No. 62).

¥ Rocker switches (bottom row): - Throttle backup/

throttle lock - Ether starting aid - Air conditioning - Body up sound

reduction

- Secondary steering and brake retraction

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To the right of the rocker switches is the Message Center Module. The Message Center Module contains ten alert indicators and a message display window.

The alert indicators on the message center module represent the following systems:

Top row (from left to right)

¥ Engine Oil Pressure--Minimum operating pressures: - Low Idle - 44 kPa (6.4 psi)

- High Idle - 250 kPa (36 psi)

¥ Parking Brake ON or Brake Master Cylinder Overstroke

¥ Torque Converter Oil Temperature or Brake Oil Temperature--Maximum operating temperature: 121 ¡C (250 ¡F)

¥ Battery Charging--Minimum voltage on Message Center pin 1: 23 Volts. Minimum "R" terminal frequency/voltage: 95 Hz/12.4 to 14.75 DC volts.

¥ Engine Maintenance Required--Steering pressure low Air filter restriction Engine coolant flow low

¥ Message center module

¥ Alert indicators (top row):

- Engine oil pressure - Parking brake ON or

brake master cylinder overstroke - Torque converter oil

temperature or brake oil temperature - Battery charging - Engine maintenance

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Bottom row (from left to right)

¥ Air Filter Restriction--Maximum allowable restriction: 7.5 kPa (30 inches of water)

¥ Steering Pressure Low

¥ Transmission/Torque Converter Oil Filter Restricted--Maximum differential pressure: 250 kPa (36 psi)

¥ Engine Coolant Flow Low

¥ Check Engine--Lights only when there are active engine fault codes

The message display window has a row of six digits, a decimal point between certain digits, six text symbols (units of measure), a x10 symbol and a service meter symbol that show machine system conditions and other service and setup information. The type of information shown on the screen depends on the message center operating mode.

¥ Alert indicators (bottom row): - Air filter restriction - Steering pressure

low

- Transmission oil filter restricted - Engine coolant flow

low

- Check engine

¥ Message display window

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20 5 4 3 2 1

Shown is the fuse panel located behind the operator's seat. A laptop computer with the Electronic Technician (ET) software installed can be connected to the CAT Data Link connector (1) to obtain diagnostic information and perform programming functions on all of the electronic controls.

A 12 Volt/5 amp power port (2) provides an additional power supply for a laptop computer.

A laptop computer with the Truck Production Management System (TPMS) or VIMS software installed can be connected to the diagnostic connector (3) to obtain diagnostic and production information from the TPMS or VIMS Electronic Control.

Two Service Switches (4) and (5) are used to access the Caterpillar Monitoring System Message Center for stored diagnostic information. The switches are labeled with an "S" for SET or SCROLL and a

"C" for CLEAR. The Diagnostic Mode of the Message Center is changed by depressing and holding both service switches "S" and "C". When the desired mode is shown on the display, the switches can be released. By following the instructions in the Caterpillar Monitoring System Service Manual, the serviceman can program or diagnose faults in all electronic controls on the CAT Data Link.

1. CAT Data Link connector

2. 12 Volt/5 amp power port 4. Caterpillar Monitoring System message center service switches 3. TPMS/VIMS diagnostic connector

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21

41.4

SERV CODE SERVICE METER MODE

170

ODOMETER MODE

700

DIGITAL TACHOMETER MODE

74

RESETTABLE LOAD COUNTER MODE

030

DIAGNOSTIC SCROLLING MODE MILES or KM RPM

L

271 F05

SERV CODE SERV CODE

MID CID FMI

INPUTS

- ENGINE SPEED/TIMING SENSOR - ALTERNATOR "R" TERMINAL - ENGINE OIL PRESSURE

- TRANSMISSION OUTPUT SPEED SENSOR

- ENGINE SPEED/TIMING SENSOR

- BODY UP SWITCH

(AFTER 10 SECONDS ACTIVATION) Use "C" Service Switch to Clear

OPERATOR MODES

The Caterpillar Monitoring System has eight different possible modes of operation. Each mode provides important information regarding the condition of the machine and setup of the monitoring system. On the message center module display window, each mode is shown as a number. The mode of operation is changed using either the Service Switches located on the fuse panel behind the Operator or the Operator Mode Scroll Switch located on the dashboard. Only some modes are accessible to the Operator by using the dashboard-mounted rocker switch in Mode 0.

After the Caterpillar Monitoring System first powers up, the message center display window will be in Mode 0. In Mode 0, the display window six-digit readout shows various machine system conditions to the

Operator. The digital readout normally shows the service meter. Using the Operator Mode Scroll Switch, the Operator may scroll through the different Operator modes. As the display scrolls, it will show the following information:

¥ Message center module display window

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¥ Service Meter Mode: The message center module keeps track of the engine's total number of operating hours. When in service meter mode, the six digit readout shows total machine operating hours. The service meter symbol is ON to indicate the display is functioning as a service meter. The operating hours will only increase when there are input signals from the engine speed timing sensor, the alternator "R" terminal and the engine oil pressure sensor. If there is an Active Fault, SERV CODE will be displayed in the window.

¥ Odometer Mode: In this mode, the six-digit readout displays the total distance the machine has traveled. The units indicator will show MILES or KM, depending on the units of measure setting. The distance traveled will only increase when there is an input signal from the transmission output speed sensor.

¥ Digital Tachometer Mode: This mode displays the engine speed in revolutions per minute on the six-digit display. The units indicator shows RPM. The engine speed/timing sensor provides the input signal to the message center module.

¥ Resettable Load Counter Mode: Displays the number of loads since last re-set by the operator. The number of loads is calculated as equal to the number of times the body has been raised for more than ten seconds. The body up switch provides the input signals to the message center module. The load count can be cleared by depressing the "C" Service Switch located behind the Operator's seat.

¥ Diagnostic Scrolling Mode: Using this mode, service personnel or the operator can view the faults the message center has detected. Faults CANNOT be placed on hold or cleared in this mode. "SERV CODE" will only be displayed if the fault is ACTIVE.

Fault Codes consist of two parts:

¥ MID - Module Identification. 030--Monitor, 036--ADEM II, 027--EPTC III, 116--ARC/TCS

¥ CID, FMI - Component Identification and Failure Modifier Refer to the Serviceman's Handouts for a listing of the Diagnostic Codes used on the D-series update Off-highway Trucks.

NOTE: During engine cranking, if the Caterpillar Pre-Lubrication System is installed, a "P" will appear on the display during

pre-lubrication.

During engine cranking, if the ether starting aid is installed, an "E" will appear on the display during ether injection.

¥ Operator modes: - Service meter mode - Odometer mode - Digital tachometer mode - Resettable load counter mode - Diagnostic scrolling mode ¥ Diagnostic codes in serviceman's handouts

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22 -1-HARNESS CODE MODE 88 NUMERIC READOUT MODE SERVICE MODE LOG MODE 030 UNITS MODE MILES LOG 271 F05 SERV CODE SERV CODE

MID CID FMI

95 715 kPa 75 59 -2- -3- -4- -5- -6-PERMANENT LOAD COUNT MODE SERV CODE °C

GA-1 (engine coolant) GA-2 (brake oil) GA-3 (system air) GA-4 (fuel)

°C -1057 L US KM SI SERVICE MODES

USE "S" SERVICE SWITCH TO SCROLL GAUGES

USE "C" SERVICE SWITCH TO CHANGE UNITS

USE "S" SERVICE SWITCH TO SCROLL FAULTS USE "C" SERVICE SWITCH TO CLEAR FAULTS

ALL GAUGES AND INDICATORS

DISPLAY EXTREME CONDITIONS RECORDED

-7-USE "S" SERVICE SWITCH TO SCROLL SUB-MODES DIAGNOSTIC

AND PROGRAMMING

MODE

USE "C" SERVICE SWITCH TO CLEAR

n n 3 F 3 F L

The Service Technician can use the message display to check other machine condition information by selecting the different modes available. Depress both Service Switches behind the Operator's seat to Scroll

through the Modes. Release the switches to enter a Mode when its number is displayed. The seven Service Modes are described below. ¥ Harness Code Mode 1: This mode shows the machine model that the

monitoring system is installed on. 769D through 777D pre-update Off-highway Trucks are all "34." D-series update truck harness codes are:

769D--"62" 771D--"61" 773D--"60" 775D--"59"

¥ Numeric Readout Mode 2: This mode assists service personnel with troubleshooting sensor inputs. Numeric readout mode more accurately shows the same information as that shown on the gauges. The digital readout will display one gauge value at a time. To scroll through the four gauges, depress the "S" Service Switch and release the switch when the desired gauge number is displayed.

¥ Service modes: - Harness code mode 1 - Numeric readout mode 2 - Service mode 3 - Log mode 4 - Units mode 5 - Permanent load count mode 6 - Diagnostic and programming mode 7

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¥ Service Mode 3: The message center module detects faults that occur with sensor/sender inputs and message center module outputs. The message center will then record the fault and turn on the "SERV CODE" indicator. If the fault goes away, the "SERV CODE" indicator is turned off. The fault code remains stored for future reference. This mode helps service personnel see and trouble shoot faults that the message center module has detected. Faults from other machine systems that are attached to the Data Link are also shown in this mode.

When a fault is displayed in the window, the Action Alarm will sound when the component or circuit changes state. For example, if the display shows the fault code for the torque converter temperature sensor and the technician unplugs and then plugs in the connector to the torque converter temperature sensor, the Action Alarm will sound if the

Message Center Module detects a change from an OPEN to a completed circuit.

Use the "S" Service Switch to scroll through logged faults. Use the "C" Service Switch to clear logged faults that have been repaired.

¥ Log Mode 4: Log mode is a management and maintenance tool, useful for tracking machine history. The message center module records the extreme value for each machine condition monitored. When in this mode, each gauge in the four-gauge cluster will display its highest or lowest recorded condition and the speedometer and tachometer will display their highest recorded values. Alert Indicators will also light when an abnormal condition has existed.

Use the "C" Service Switch to clear the logged values. Mode 4 must also be exited before the logged values will be cleared from memory. ¥ Units Mode 5: This mode is used to toggle the Ground Speed display

(MPH/km/h) between U.S. and SI (metric) units of measure. Use the "C" Service Switch to change the units of measure.

¥ Permanent Load Count Mode 6: Displays the total number of loads accumulated since the machine was put into production. The number of loads is calculated as equal to the number of times the body has been raised for more than 10 seconds. This Mode is not resettable.

¥ Action alarm sounds when fault is

displayed

¥ SERV CODE on for active faults

¥ Use "S" service switch to scroll faults

¥ Use "C" service switch to clear faults

¥ Log mode indicates extreme conditions

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¥ Diagnostic and Programming Mode 7: The Caterpillar Monitoring System display for Mode 7 has been expanded to include several sub-modes to extend the diagnostic capabilities. After entering Mode 7, use the "S" service switch to scroll through the sub-modes. The operator scroll switch and the "C" service switch can also be used in some of the sub-modes. The sub-modes in Mode 7 are as follows:

7.1 Shift Monitoring Mode--displays the position of the shift lever sensor on the left of the display and the position of the transmission gear switch on the right of the display. The D6 digit will display an "L" when the lockup clutch is ENGAGED.

n n <--cane n, actual gear n, lockup clutch OFF 1 r 1 r <--cane 1R, actual gear 1R, lockup clutch OFF 3 F 3 F L <--cane 3F, actual gear 3F, lockup clutch ENGAGED -- -- -- -- --

--D1 D2 D3 D4 D5 D6 <--digital position on display

7.2 Transmission Output Speed (TOS) Display Mode--displays the rpm of the TOS sensor.

T 1 8 3 4 <--TOS = 1834

-- -- -- -- --

7.3 Torque Converter Output Speed (COS) Display Mode--displays the rpm of the COS sensor (if equipped).

C 1 8 3 4 <--COS = 1834

-- -- -- -- --

7.4 Engine Output Speed (EOS) Display Mode--displays the rpm of the EOS sensor.

E 1 8 3 4 <--EOS = 1834

-- -- -- -- --

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7.5 Hoist Display Mode--displays the hoist lever sensor INPUT to the Transmission and Chassis Control or the hoist lever OUTPUT from the Transmission and Chassis Control. The input and output can be different depending on the hoist lever strategy. For example, if a machine is started with the hoist lever in FLOAT, the hoist strategy will keep the body in HOLD until the lever is cycled from FLOAT to HOLD and then back to FLOAT. Therefore, the input can be FLOAT and the output will be HOLD.

H L 0 H <--hoist lever in HOLD

H L 4 0 L <--hoist lever in 40% LOWER H L 8 0 R <--hoist lever in 80% RAISE H L 1 0 0 F <--hoist lever in 100% FLOAT -- -- -- -- --

Depress the Operator Scroll Switch and the above display changes to show the hoist OUTPUT. The "L" changes to an "O" and the state of the hoist system is displayed in the same format.

H 0 0 S <--hoist output in SNUB -- -- -- -- --

7.6 Transmission Gear Switch Input Mode--displays the transmission gear switch input signals to the Transmission and Chassis Control. Transmission gear switch inputs correspond to pins 29, 30, 31, 32, 33 and 35 in the J1 connector of the Transmission and Chassis Control. If the particular input is grounded, a "0" will be displayed. If the input is not grounded (OPEN), a "1" will be displayed. A normal transmission gear position will have two of the five gear wires grounded along with the ground verify signal (pin 35). Pin 35 should always be grounded and a "0" should always be displayed in the D1 position of the display. Therefore, a correctly functioning

Transmission Gear Switch and Harness should always have three 0's and three 1's for each gear position.

0 0 0 1 1 1 <--pins grounded in NEUTRAL 32 & 33 0 0 1 0 1 1 <--pins grounded in REVERSE 31 & 33 0 0 1 1 0 1 <--pins grounded in 1st 30 & 33 0 0 1 1 1 0 <--pins grounded in 2nd 29 & 33 0 1 0 0 1 1 <--pins grounded in 3rd 31 & 32 0 1 0 1 0 1 <--pins grounded in 4th 30 & 32 0 1 0 1 1 0 <--pins grounded in 5th 29 & 32 0 1 1 0 0 1 <--pins grounded in 6th 30 & 31 0 1 1 0 1 0 <--pins grounded in 7th 29 & 31 -- -- -- -- --

--D1 D2 D3 D4 D5 D6 <--digital position on display 35 33 32 31 30 29 <--pin number in the J1 connector

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7.7 Economy Shift Program Mode--displays whether the Economy Shift feature is ON or OFF. The Operator can select between faster cycle times or better fuel economy. Turning this feature ON or OFF changes the torque map used by the engine control and the shift points used by the

transmission control. ON is ECONOMY mode. OFF is FULL POWER mode. When the Economy Shift feature is ON, full power is still used in 1st and 2nd Gear. The Economy torque map is only used in gears THREE and up.

Use the "C" Service Switch to turn this feature ON or OFF..

O F F <--setting at OFF -- -- -- -- --

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¥ Electronic Technician (ET)

23

Shown is the 7X1700 Communication Adapter and a laptop computer with the Electronic Technician (ET) diagnostic software installed. The communication adapter is connected to the CAT Data Link diagnostic connector located on the fuse panel.

The new electronic controls [Transmission and Chassis control

(EPTC III), Integrated Brake Control (IBC), ARC and TCS] used on the D-series update trucks no longer have diagnostic windows to access diagnostic information. The new controls are called Multiple Application Controls with 14 output capability (MAC14). In order to perform

diagnostic and programming functions in the new MAC14 controls, the service technician must use a laptop computer with ET.

ET version 2.0 or greater must be used to communicate with the Integrated Brake Control (IBC).

¥ ET must be used with new MAC14 controls

¥ ET version 2.0 required for IBC

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24

1

2

Vital Information Management System (VIMS)

The Vital Information Management System (VIMS) is being tested as a possible future attachment on the D-series update trucks.

If a truck is equipped with the VIMS, the message center control module of the Caterpillar Monitoring System is replaced with the VIMS message center module (1) and the keypad module (2).

The message center module consists of an alert indicator, a universal gauge and a message display window. The alert indicator flashes when a Category 1 Warning is present. The universal gauge displays the status of the sensor selected for viewing by depressing the GAUGE key on the keypad. The message display window shows various types of text information to the operator.

¥ VIMS possible future attachment 1. Message center module: - Alert indicator - Universal gauge - Message display window

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2. Keypad module The keypad module allows the operator or a service technician to interact with the VIMS. Some of the functions that can be performed by the keypad are:

- Calibrate Payload Monitor PAYCAL 729225

- Payload Resettable Totals TOT 868

- Reset Displayed Data RESET 73738

- Display Self Test TEST 8378

- Reset Service Light SVCLIT 782548

- Show Acknowledged Events EACK 3225

- Show Event Statistics ESTAT 37828

- Show Event List ELIST 35478

- Start Event Recorder EREC 3732

- Start/Stop Data Logger DLOG 3564

- Reset Data Logger DLRES 35737

- Odometer Set/Reset ODO 636

(requires VIMS PC connection)

- Machine Status MSTAT 67828

- Change Language LA 52

- Change Units UN 86

- Change Backlight BLT 258

- Change Display Contrast CON 266

(requires Updated Message Center)

OK Key--Used to complete keypad entries and to acknowledge events. Acknowledging an event will remove the event from the display temporarily. Severe events cannot be acknowledged.

GAUGE key--Displays parameters monitored by VIMS. Depressing the arrow keys will scroll through the parameters. Entering the parameter number and the GAUGE key selects that parameter.

F1 Key--Provides additional information on the current event being displayed. For SYSTEM events, the MID, CID, FMI is displayed. For MACHINE events, the current parameter value is displayed (temperature, pressure, rpm).

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25 ¥ VIMS TRANSMISSION AND CHASSIS CONTROL SENSORS ADEM II CONTROL SERVICE LAMP MESSAGE CENTER MODULE GAUGE CLUSTER

MODULE MODULEKEYPAD

SENSORS VIMS INTERFACE MODULE VIMS INTERFACE MODULE SENSORS VIMS SERVICE TOOL AND SOFTWARE

CAT DATA LINK SERVICE KEYSWITCH ACTION LAMP ACTION ALARM ELECTRONIC TECHNICIAN/ECAP

VIMS MAIN MODULE

DISPLAY DATA LINK VIMS

RS-232 PORT

CAT DATA LINK

VITAL INFORMATION MANAGEMENT SYSTEM (VIMS) SPEEDOMETER/ TACHOMETER MODULE 3F 12MPH km/h KEYPAD DATA LINK INTEGRATED BRAKE CONTROL (ARC) (TCS)

The VIMS operates very similar to the Caterpillar Monitoring System. The VIMS uses two interface modules to receive input signals from many sensors located around the machine. The VIMS also communicates with other electronic controls on the machine. The VIMS provides the

operator and the service technician with a complete look at the current and past conditions of all the systems on the truck.

If the truck is equipped with the VIMS, the TPMS is an integral part of the VIMS. Access to the TPMS information is provided through the VIMS message center and keypad modules and a laptop computer with the VIMS PC software installed.

While VIMS monitors all of the systems on the truck, ET is used for programming, running diagnostic tests and retrieving logged information from the engine, transmission and chassis, ARC and TCS electronic controls.

¥ ET required for programming and diagnostics

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1. VIMS main module 2. VIMS interface module #1 3. VIMS interface module #2 4. Transmission and chassis control 5. ARC and TCS control 26 5 4 3 1 2

Located in the compartment at the back of the cab is the VIMS Main Module (1), the VIMS Interface Module #1 (2) and the VIMS Interface Module #2 (3). These components make up the heart of the VIMS. Also in this location is the transmission and chassis control (4) and the ARC and TCS control (5). All of these electronic controls, along with the engine control, communicate with each other on the CAT Data Link. All of the information from these controls can be accessed through the VIMS message center or a laptop computer with ET or VIMS PC software.

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¥ VIMS connector

27

Shown is a laptop computer with the VIMS PC diagnostic software installed. The laptop computer is connected to the VIMS diagnostic connector. This connector is the same one used for TPMS on trucks without the VIMS.

Some of the operations that can be performed with a laptop computer with VIMS PC installed are:

- View real time data (similar to the status menu of ET) - View payload data

- Start and stop a data logger - Calibrate the payload system

- Upload source and configuration files (similar to flash programming with ET)

- Assign serial and equipment numbers - Reset onboard date, time and hour meter

- Download event list, data logger, event recorder, payload data, trend data, cumulative data and histogram data

INSTRUCTOR NOTE: For more detailed information on the VIMS, refer to the Service Manual Module "Vital Information Management System (VIMS)" (Form SENR6059).

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¥ Torque converter: - Provides a fluid

coupling

- Multiplies torque - Provides direct drive

operation 28 1 4 3 2 POWER TRAIN

Power Train Components

The first component in the power train is the torque converter. The torque converter provides a fluid coupling that permits the engine to continue running with the truck stopped. In converter drive, the torque converter multiplies torque to the transmission. At higher ground speeds, a lockup clutch engages to provide direct drive. The NEUTRAL and REVERSE ranges are converter drive only. FIRST SPEED is converter drive at low ground speed and direct drive at high ground speed. SECOND through SEVENTH SPEEDS are direct drive only. The torque converter goes to converter drive between each shift (during clutch engagement) to provide smooth shifts.

Mounted on the torque converter case are the lockup clutch control valve (1), the outlet pressure relief valve (2), the transmission and torque converter pump (3) and the transmission and torque converter suction screen (4).

1. Lockup clutch control valve

2. Outlet pressure relief valve 3. Transmission and torque converter pump 4. Transmission and torque converter suction screen

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¥ 775D update truck 1. Transfer gears 2. Transmission 3. Differential 29 2 3 1

Shown are some of the power train components in a 775D update truck. Power flows from the torque converter through a drive shaft to the transfer gears (1). The transfer gears are splined to the transmission. The transmission (2) is located between the transfer gears and the differential (3). The transmission is electronically controlled and

hydraulically operated like all other ICM (Individual Clutch Modulation) transmissions in Caterpillar rigid frame trucks.

The transmission is a power shift planetary design which contains seven hydraulically engaged clutches. The transmission provides seven FORWARD speeds and one REVERSE speed.

The differential is located in the rear axle housing behind the

transmission. Power from the transmission flows through the differential and is divided equally to the final drives in the rear wheels. The final drives are single reduction planetaries.

¥ Transmission is power shift planetary design

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¥ Torque converter housing is oil sump ¥ Two section pump:

1. Transmission scavenge 2. Transmission and torque converter charging 3. Transmission scavenge oil return baffle cover 4. Suction screen cover 5. Transmission and torque converter charging filters 30 4 3 2 1 5

Power Train Hydraulic System

The torque converter housing is the oil sump for the transmission and torque converter oil supply.

A two section transmission and torque converter pump is located at the rear of the torque converter. The rear section is the transmission scavenge section (1) of the pump and the front section is the transmission and torque converter charging section (2) of the pump.

The transmission scavenge section pulls oil through the magnetic screen located at the bottom of the transmission case (see next slide). The scavenged oil from the transmission is transferred into the torque converter case through a baffle (diffuser) located behind the cover (3). The transmission and torque converter charging section of the pump pulls oil from the torque converter case through the suction screen located behind the cover (4). Oil flows from the charging section to the

transmission and torque converter charging filters (5). Charging oil flows in two directions from the filters:

- Charging oil flows to the torque converter lockup valve located on top of the torque converter.

- Charging oil also flows to the transmission control valves located on top of the transmission.

¥ Charging oil flows in two directions: - To torque converter

lockup clutch valve - To transmission

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¥ Transmission magnetic scavenge screen (arrow)

31

Shown is the transmission scavenge screen (arrow) and the magnet

assembly that fits inside the screen. The screen is located in the bottom of the transmission case. The screen should always be checked for debris if a problem with the transmission is suspected.

Oil is scavenged from the transmission by the rear section of the transmission and torque converter pump (see previous slide).

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32

2

3

1

Shown are the transmission and torque converter charging filters (1). Transmission and torque converter oil samples can be taken at the Scheduled Oil Sampling (S¥O¥S) tap (2).

A transmission and torque converter filter bypass switch (3) is located on the filter base. The bypass switch provides input signals to the Caterpillar Monitoring System or the VIMS which informs the operator if the

transmission and torque converter filters are restricted.

1. Transmission and torque converter filters 2. Transmission/TC S¥O¥S tap 3. Transmission/TC filter bypass switch

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1. Torque converter lockup valve

2. Lockup valve supply port 3. Lockup solenoid 33 2 1 4 3

The transmission and torque converter charging pump supplies oil to the torque converter lockup valve (1) through the inlet port (2). When the lockup solenoid (3) is energized by the transmission and chassis control, the lockup valve supplies oil to ENGAGE the lockup clutch in the torque converter.

Torque converter lockup clutch pressure can be measured at the tap (4). Torque converter lockup clutch pressures are as follows:

769D/771D--Pressure will increase to 2065 ± 100 kPa (300 ± 15 psi) for 0.15 seconds, then decrease and hold at 1720 ± 100 kPa (250 ± 15 psi). 773D/775D--Pressure will increase to 2410 ± 100 kPa (350 ± 15 psi) for 0.15 seconds, then decrease and hold at 2065 ± 100 kPa (300 ± 15 psi). To check the lockup clutch pressure the drive shaft must be disconnected at the torque converter or the rear axles must be removed. Move the shift lever to first forward and raise the engine speed to HIGH IDLE. The lockup clutch will engage at approximately 6.4 km/h (4 mph).

An 8T5200 Signal Generator/Counter can also be used to shift the transmission.

The lockup clutch pressure is not adjustable. If the lockup clutch pressure is not correct, verify that the lockup valve is operating correctly. Check for loose or sticking components or debris in the valve. If the lockup valve is operating correctly and the lockup clutch pressure is incorrect, a new flash file may be required.

4. Torque converter lockup clutch pressure tap ¥ Lockup clutch pressure NOT adjustable ¥ Lockup clutch pressure test

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34

¥ Lockup clutch control valve operation

LOCKUP SOLENOID

PIN

DRAIN

PUMP

SUPPLY

LOCKUP

PRESSURE

TORQUE CONVERTER LOCKUP VALVE

CONTROL

SPOOL

The transmission and chassis control provides a Pulse Width Modulated (PWM) signal to the lockup solenoid to control the lockup pressure. When the lockup solenoid is energized, the pin moves to the right and pushes against the ball. The ball blocks the pump supply oil from flowing to drain. Pressure increases in the chamber to the left of the control spool and moves the spool to the right.

When the control spool moves to the right, pump supply oil flows to the lockup clutch. The transmission and chassis control opens and closes the ball drain port as needed to maintain the correct lockup clutch pressure.

The lockup clutch valve is often referred to as the Electronic Clutch Pressure Control (ECPC) valve because it can control clutch pressure electronically. A similar valve is used on Track-type Tractors and Wheel Loaders.

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35 2 5 6 3 7 4 1

Shown is the Individual Clutch Modulation (ICM) transmission hydraulic control valve. Oil flows from the transmission and torque converter charging filters through the inlet port (1) to the transmission hydraulic control valve and the shift solenoids (2). The charging oil is used to shift the transmission and fill the clutches. Some of the charging oil drops to the bottom of the housing to be scavenged, but most of the oil flows to the torque converter through the outlet hose (3) to provide charging oil for the torque converter. The torque converter inlet relief valve (4) limits the maximum pressure to the torque converter.

The setting of the torque converter inlet relief valve is 930 kPa (135 psi). The transmission charging pressure relief valve is part of the transmission hydraulic control valve. The relief valve limits the maximum pressure in the transmission charging circuit. Transmission charging pressure can be measured at the tap (5). Transmission pressure should be a minimum of 2480 kPa (360 psi) at LOW IDLE and a maximum of 3200 kPa (465 psi) at HIGH IDLE.

Transmission clutch pressures are measured at the pressure taps (6). Lubrication and cooling oil from the the transmission and torque converter oil cooler enters the transmission through inlet port (7).

1. Transmission charging oil inlet port

2. Shift solenoids 3. Torque converter

charging oil supply hose

4. Torque converter inlet relief valve

5. Transmission charging pressure tap 6. Transmission clutch pressure taps 7. Transmission lube inlet port

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¥ Transmission lube tap (arrow)

36

Shown is the left side of the transmission. Transmission lube pressure can be measured at the tap (arrow) located below the lubrication supply hose. Lube pressure should be greater than 3.5 kPa (0.5 psi) at LOW IDLE and between 140 to 205 kPa (20 to 30 psi) at HIGH IDLE.

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37 ¥ ICM transmission hydraulic control valve TRANSMISSION CASE C DOWNSHIFT SOLENOID UPSHIFT SOLENOID TORQUE CONVERTER CHARGING PUMP CHARGING FILTERS ROTARY ACTUATOR SELECTOR VALVE GROUP ROTARY SELECTOR SPOOL NEUTRALIZER VALVE PRIORITY REDUCTION VALVE TORQUE CONVERTER INLET RELIEF VALVE RELIEF VALVE A B D E F G H PUMP PRESSURE DOWNSHIFT PRESSURE PILOT OIL PRESSURE LUBE PRESSURE ICM

HYDRAULIC SYSTEM _UPSHIFT PRESSURE

PRESSURE CONTROL GROUP

SCAVENGE PUMP

OIL COOLER TO TRANSMISSION LUBE LOCKUP

VALVE

Shown is a sectional view of the ICM transmission hydraulic control valve group.

Pump supply oil flows to the shift solenoids, the priority reduction valve, the relief valve and the pressure control group. Pump supply oil also flows to the lockup valve. The relief valve controls the maximum charging pressure in the system. The priority reduction valve reduces transmission relief pressure to be used as pilot oil. Pilot oil flows through the neutralizer valve to the rotary selector spool. The neutralizer valve prevents the clutches from filling with oil if the engine is started with the transmission in gear. The neutralizer valve will only allow pilot oil to flow to the rotary selector spool if it is in NEUTRAL.

The rotary actuator is connected to the rotary selector spool. If a shift solenoid is energized, pump supply oil flows to the rotary actuator and rotates the rotary selector spool. The rotary selector spool directs pilot oil to one or two valve stations and allows the clutches to fill with oil. The valve stations control the modulation of clutch engagement and

dis-engagement.

The torque converter inlet relief valve limits the maximum pressure to the torque converter.

¥ Priority reduction valve

¥ Neutralizer valve

¥ Rotary actuator ¥ Rotary selector spool

¥ Torque converter inlet relief valve

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1. Torque converter charging oil inlet port 38 3 5 2 4 1

Charging oil flows from the transmission and enters the torque converter through inlet port (1). The torque converter charging oil enters the torque converter and provides a fluid coupling.

The torque converter charging oil then either drops to the bottom of the housing or flows through the torque converter outlet relief valve (2). The outlet relief valve limits the pressure inside the torque converter. The outlet relief pressure can be measured at the tap (3) on the outlet relief valve. The outlet relief pressure should be between 205 and 550 kPa (30 and 80 psi) at Stall Speed. Stall Speed should be between

1760 and 1890 rpm.

All the oil from the torque converter outlet relief valve flows from port (4) through the transmission and torque converter oil cooler located on the right side of the engine. Oil flows from the oil cooler back to the transmission for lubrication. Transmission lube oil flows through the transfer gears and the transmission to cool and lubricate the internal components.

A torque converter outlet temperature sensor (5) provides an input signal to the Caterpillar Monitoring System or the VIMS which informs the operator of the torque converter outlet temperature.

2. Torque converter outlet relief valve 3. Outlet relief valve

pressure tap

4. Torque converter outlet port to oil cooler

5. Torque converter outlet temperature sensor

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39

¥ Transmission and torque converter hydraulic system ¥ Two section pump:

- Transmission scavenge - Transmission and torque converter charging TORQUE CONVERTER INLET TORQUE CONVERTER OUTLET TORQUE CONVERTER LOCKUP CLUTCH SUPPLY SUCTION SCREEN TO TRANSMISSION AND TORQUE CONVERTER CHARGING FILTERS LOCKUP VALVE FROM TRANSMISSION MAGNETIC SCAVENGE SCREEN SHIFT SOLENOIDS MAGNETIC SCAVENGE SCREEN TRANSMISSION AND TORQUE CONVERTER CHARGING FILTERS TRANSMISSION AND TORQUE CONVERTER OIL COOLER RETURN BAFFLE

TRANSMISSION AND TORQUE CONVERTER HYDRAULIC SYSTEM

Shown is the transmission and torque converter hydraulic system. A two section transmission and torque converter pump is located at the rear of the torque converter. The rear section is the transmission scavenge section of the pump and the front section is the transmission and torque converter charging section of the pump.

The transmission scavenge section pulls oil through the magnetic screen located at the bottom of the transmission case. The scavenged oil from the transmission is transferred into the torque converter case through a baffle (diffuser).

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¥ Transmission and torque converter charging section

The transmission and torque converter charging section of the pump pulls oil from the torque converter case through the suction screen. Oil flows from the charging section to the transmission and torque converter charging filters. Charging oil flows in two directions from the filters:

- Charging oil flows to the torque converter lockup valve located on top of the torque converter.

- Charging oil also flows to the transmission control valves located on top of the transmission.

The charging oil that flows to the torque converter lockup valve is blocked from the lockup clutch until the lockup valve solenoid is

energized by the transmission and chassis control. When the lockup valve solenoid is energized, the lockup valve supplies oil to ENGAGE the lockup clutch in the torque converter.

The charging oil that flows to the transmission hydraulic control valve also supplies the shift solenoids. The charging oil is used to shift the transmission and fill the clutches. Some of the charging oil drops to the bottom of the housing to be scavenged, but most of the oil flows to the torque converter to provide charging oil for the torque converter.

The torque converter charging oil enters the torque converter and provides a fluid coupling. Charging oil then either drops to the bottom of the housing or flows through the torque converter outlet relief valve. The outlet relief valve limits the pressure inside the torque converter.

The oil from the torque converter outlet relief valve flows through the transmission and torque converter oil cooler located on the right side of the engine. Oil flows from the oil cooler back to the transmission for lubrication. Transmission lube oil flows through the transfer gears and the transmission to cool and lubricate the internal components.

¥ Torque converter lockup clutch supply oil ¥ Transmission charging oil ¥ Torque converter charging oil ¥ Transmission lube

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40

Transmission and Chassis Control (EPTC III)

The transmission and chassis control (arrow) is located in the

compartment at the rear of the cab. The transmission control used in the D-series pre-update trucks is referred to as the second generation Electronic Programmable Transmission Control (EPTC II).

The transmission control used in the D-series update trucks performs the transmission control functions plus some other machine functions (hoist and secondary steering control). Because of the added functionality of the control, it is now referred to as the transmission and chassis control. But, to keep written material to a minimum, we will often refer to this control as the third generation Electronic Programmable Transmission Control or (EPTC III).

The new control is a MAC14 style electronic control, which means that it is a Multiple Application Control capable of 14 outputs (MAC14). The MAC14 does not have a diagnostic window like EPTC II. Diagnostic and programming functions must all be done with an Electronic Control Analyzer Programmer (ECAP) or a laptop computer with the Electronic Technician (ET) software installed. ET is the tool of choice because the MAC14's can be reprogrammed with a "flash" file using the Winflash application of ET. ECAP cannot upload "flash" files.

MAC14's look like the second generation Advanced Diesel Engine Management (ADEM II) electronic control with two 40-pin connectors, but MAC14's do not have fittings for cooling fluid. Also, there is no access plate for a personality module.

¥ Transmission and chassis control (arrow)

¥ Transmission and chassis control called EPTC III

¥ MAC14 style control - No diagnostic

window

- Diagnostics and programming

requires ECAP or ET

¥ MAC14 looks like ADEM II

769D-771D-773D-775D.PDF

TECHNICAL PRESENTATION