service training 740 articulated truck

Service TrainingSERV2717November 2001

STUDENT MATERIALS

PART OF TECHNICAL INSTRUCTION MODULE SERV2717

740 ARTICULATED TRUCKPOWER TRAIN

740

MODULE OBJECTIVES

All the following objectives require a Caterpillar 740 Articulated Truck.At the completion of this module, you will be able to:

1. Given the appropriate service manual module, locate and identify thepower train hydraulic system components and record the answers onthe Lab A Worksheet.

2. Given the appropriate service manual module, perform the power trainhydraulic system tests on the machine and record the results on theLab B Worksheets.

3. Given a machine, perform the torque converter stall test during a labexercise.

4. Given class notes and reference material, explain the functions of thepower train hydraulic components during a posttest.

5. Given class notes and reference material, identify the selector andpressure control valve components on a graphic cutaway during aposttest.

6. Given class notes and reference material, correctly answer power trainhydraulic system operation multiple choice questions on a posttest.

7. Given a 740 Articulated Truck, the appropriate service manualmodule, class notes, and the case study worksheets, list the possibleanswers during each step of the troubleshooting process.

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- 2 - Student Materials

BACKGROUNDINFORMATION

INDIVIDUAL EXERCISE

MATERIALS NEEDED

Lab A: Power Train Hydraulic System ComponentIdentification

This lab measures your ability to identify the Power Train HydraulicSystem components for the 740 Articulated Truck.

______Class notes

______Lab A Worksheets

______740 Articulated Truck

______Mechanic's tool box with hand tools

______Pen or pencil

Use the "Lab A: Power Train Hydraulic System ComponentIdentification Worksheet No. 1" during the presentation to take notes onthe location and function of each component.

In the lab, use Lab A Worksheet No. 1 to identify the power train systemcomponents by matching the lettered or numbered tags on the componentswith the names on the worksheet.

Use Worksheet No. 2 during the presentation to take notes on the functionof the transmission control valve components. During the lab exercise,fill in the blanks with the correct letter from the graphic and write thefunction for each component.

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Student Materials- 4 -

Lab A: Power Train Hydraulic System Component IdentificationWorksheet No. 1

Directions: Use this worksheet during the presentation to take notes on the location and function ofeach component. During the lab exercise, match the tag attached to the component withthe correct name.

Tag No. Component

___ Transmission Pump Suction ScreenLocation:Function:

___ Transmission PumpLocation:Function:

___ Transmission Oil FilterLocation:Function:

___ Transmission Control LeverLocation:Function:

___ Torque ConverterLocation:Function:

___ TransmissionLocation:Function:

___ Transfer GearLocation:Function:

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Lab A: Power Train Hydraulic System Component IdentificationWorksheet No. 1 (continued)

Tag No. Component

___ Drive Shafts (6)Location:Function:

___ Final Drives (3)Location:Function:

___ Differential and Bevel Gear Cases (3)Location:Function:

___ Transmission Actual Gear SwitchLocation:Function:

___ Transmission Oil CoolerLocation:Function:

___ Transmission/Chassis ECMLocation:Function:

___ Transmission Oil Filter Bypass ValveLocation:Function:

___ Solenoid and Relief Valve GroupLocation:Function:

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Tag No. Component

___ Transfer Gear PumpLocation:Function:

___ Transfer Gear Oil FilterLocation:Function:

___ Transfer Gear Magnetic ScreenLocation:Function:

___ Upshift SolenoidLocation:Function:

___ Downshift SolenoidLocation:Function:

___ Torque Converter Lockup Clutch SolenoidLocation:Function:

Lab A: Power Train Hydraulic System Component IdentificationWorksheet No. 2

Directions: Use this worksheet during the presentation to take notes on the function of thetransmission control valve components. During the lab exercise, use the illustrations onthe next page and fill in the blanks with the correct letter for each component.

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Pressure Control ValveFunction:

Selector and Pressure Control ValveFunction:

Torque Converter Lockup Clutch Modulating ValveFunction:

Rotary ActuatorFunction:

Torque Converter Inlet Relief ValveFunction:

Pilot Pressure Test LocationFunction:

Load Piston Body (Station A)Function:

Load Piston Body (Station B)Function:

Load Piston Body (Station C)Function:

Load Piston Body (Station E)Function:

Load Piston Body (Station F)Function:

Load Piston Body (Station G)Function:

Load Piston Body (Station H)Function:


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CG D

A

J

F

H

B

K

E

M

G L

I

M

Lab B: Power Train Hydraulic System Testing andAdjusting

This lab measures your ability to perform various testing and adjustingprocedures on 740 Articulated Truck Power Train Hydraulic System.

Using the procedures in the 740 Articulated Truck Systems Operation,Testing and Adjusting module (Form RENR5134) and the Lab BHandout, locate the power train hydraulic system test point locations andspecifications and record on the Lab B Worksheets.

Demonstrate the power train hydraulic system pressure tests using theprocedures in the 740 Articulated Truck Systems Operation, Testing andAdjusting module (Form RENR5134) and record the results on the Lab BWorksheets.

______Class notes

______Lab B Worksheets

______Lab B Handout

______740 Power Train Systems Operation, Testing and AdjustingService Manual module (Form RENR5134)


______Mechanic's tools

______1U5481 Pressure Gauge Group

______1U5482 Pressure Adapter Group (for 1U5481)

______8T5200 Generator and Counter Signal Group

______FT2796 Connector Harness

______6V6064 Transmission Test Cover

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GROUP EXERCISE

MATERIALS NEEDED

INDIVIDUAL EXERCISE


Lab B: Transmission Hydraulic System Pressure Tests Worksheet

Machine Model________________________ Date_____________________

Serial Number_________________________ S.M.H.___________________

VISUAL CHECKS:

Oil level______________ Oil leaks?____________ Air/water in oil?____________

Pressure Tests

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Low Idle

TEST

High Idle

Torque ConverterLockup Clutch

Upshift Pressure

TESTPOINT SPECIFICATIONS ACTUAL

Pilot

TransmissionPump

TransmissionLube

High IdleLow Idle

Transmission Pilot Pressure

Low IdleTorque ConverterInlet Relief Valve

Initial

Max

High IdleLow Idle

Downshift Pressure

Lab B: Transmission Hydraulic System Pressure Tests Worksheet (continued)

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740 TRUCKCLUTCH CHART

SPEED CLUTCHESENGAGEDR

N

1

2

3

4

5

6

7

3 and 7

1

2 and 6

1 and 6

3 and 6

1 and 5

3 and 5

1 and 4

3 and 4

INITIAL CLUTCH PRESSURELoad Piston Plug Removed

STATION

A

CLUTCH SPECS ACTUAL

B

CE

F

GH

3

1

2

5

4

6

7

740 TRUCKCLUTCH CHART

MAXIMUM CLUTCH PRESSURELoad Piston Plug Installed

STATION CLUTCH

A

B

C

E

F

G

H

SPECS

LOW IDLE HIGH IDLE

ACTUAL

LOW IDLE HIGH IDLE

3

1

2

5

4

6

7

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Lab B: Transmission Shift Points Worksheet

MODIFIED SHIFT POINTS AT NOMINAL ENGINE SPEEDUPSHIFT SPEC ACTUAL1C to 1L

4 to 3

7 to 66 to 55 to 4

3 to 44 to 55 to 66 to 7

1 to 22 to 3

3 to 22 to 1

1L to 1T

DOWNSHIFT SPEC ACTUAL

SHIFT POINT AT NOMINAL ENGINE SPEEDUPSHIFT SPEC ACTUAL1C to 1L

4 to 3

7 to 66 to 55 to 4

3 to 44 to 55 to 66 to 7

1 to 22 to 3

3 to 22 to 1

1L to 1T

DOWNSHIFT SPEC ACTUAL

Lab B: Transfer Gear Hydraulic System Pressure Tests Worksheet

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Low Idle

TEST

Front Axle

Transfer GearLubrication Pressure

TESTPOINT SPECIFICATIONS

13

ACTUAL

Center Axle15

17

16

Axle DifferentialLocks

Supply 13

Rear Axle

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E

B F

H

A

C

D

G

1

11 7

10

8

Clutch pressures

Lab B: Transmission Hydraulic System Testing Locations Handout

8. Transmission pilot pressure

A. Clutch No. 3 B. Clutch No. 1 C. Clutch No. 2 D. Lockup clutch

E. Clutch No. 5 F. Clutch No. 4 G. Clutch No. 6 H Clutch No. 7

1. Torque converter lockup clutch pilot pressure7. Transmission pump pressure

10. Upshift pressure11. Downshift pressure

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Lab B: Transmission Hydraulic System Testing Locations Handout (continued)

6

12

6. Torque converter inlet relief pressure12. Transmission lubrication pressure

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Lab B: Transfer Gear Hydraulic System Testing Locations Handout

13

15

1617

13. Transfer gear lubrication pressure 15. Front axle differential lock test point

16. Rear axle differential lock test point 17. Center axle differential lock test point

Lab C: Torque Converter Stall Test

This lab measures your ability to perform torque converter stall test on the740 Articulated Truck Power Train Hydraulic System.

______Lab C Worksheet


______725/730/735/740 Articulated Trucks Power Train ElectronicControl Systems Operation, Troubleshooting, Testing andAdjusting module (Form RENR3442).

Following the procedures in the 725/730/735/740 Articulated TrucksPower Train Electronic Control Systems Operation, Troubleshooting,Testing and Adjusting module (Form RENR3442), perform the torqueconverter stall test procedure using the Caterpillar Monitoring System.Answer the worksheet questions after completing the test procedure.

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MATERIALS NEEDED

INDIVIDUAL OR GROUPEXERCISE

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Lab C: Torque Converter Stall Test Worksheet

1. What Caterpillar Monitoring System submode is used to perform the Torque Converter Stall test?

2. What does "Sc E08" indicate on the Caterpillar Monitoring System, if displayed during the TorqueConverter Stall test?

3 If no errors are detected during the Torque Converter Stall test, what value will the CaterpillarMonitoring System display?

DIRECTIONS

SITUATION

740 Articulated Truck Power Train Hydraulic System CaseStudy

You may use the service manual and class notes to complete the exercise.

Answer the questions on the Case Study Worksheet. Discuss the exercisewith the instructor after you have answered the case study questions.

The following case study is based on a possible field complaint.

The operator of a 740 Articulated Truck reported to his supervisor that thetransmission was slipping in third and fifth gear. He told the supervisorthat the problem had been present for a couple of days.

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The first step in in a troubleshooting process is to gather informationbefore starting any work on the machine. If possible talk to the operator.Also, check the repair history of the machine and the Caterpillar ServiceInformation System (SIS). List at list three questions you would ask anoperator to help in identifying that a problem exists. Possible answers:

Verify the problem exists. Operate the machine to duplicate the problem,preferably under similar operating conditions. Compare the operation to aknown good machine. Perform sensory checks such as looking, listening,touching, and smelling to verify a problem exists.

When troubleshooting always perform a visual inspection first. Look forthe obvious. List at least three typical items that should be inspectedduring a visual inspection. Possible answers:

After verifying a problem exists, state in your own words what theproblem is. Caution: Do not identify the solution. Possible answer:

ISOLATE PROBLEM

Gather Information

Verify

Perform VisualInspection

Power Train Hydraulic System Troubleshooting Worksheet

State Problem


Power Train Hydraulic System Troubleshooting Worksheet (continued)

The next step in the process is to list all of the possible causes of theproblem. Identify all systems and components that could be causing theproblem, including the least obvious. List at least three things that couldbe causing the problem. Possible answers:

Now, create a list of tests that should be performed and describe what thetests would determine. Prioritize the tests as to which sequence theyshould be performed in. As a general rule, always do the easiest testsfirst. Also, list diagnostic tooling required. Identify at least four tests toperform. (NOTE: the rankings are only suggested.)

Tooling needed:

Tooling needed:

Tooling needed:

Tooling needed:

LIST POSSIBLEFAULTS

Devise tests anddetermine root cause


Tooling needed:

After isolating the component, which you suspect from your test results iscausing the problem, either adjust or replace the component.

Circle the best response:

If the modulating valve initial pressure is too low and the load pistonspring rates are correct what step would you perform next?

1. Add shims behind the load piston spring

2. Remove shims from behind the load piston spring

3. Turn the load piston adjustment screw clockwise

4. Turn the load piston adjustment screw counterclockwise

After completing the repair, always verify the machine is operatingcorrectly. List at least three things you would do to make sure the repairwas done correctly.

1.

2.

3.

4.

Complete the service report after finishing the job.

Power Train Hydraulic System Troubleshooting Worksheet (continued)

REPAIR FAULT

VERIFY REPAIR

740 Articulated Truck Power Train System Componentsand Functions Posttest

Course materials and class notes may be used when taking the posttest.

Do not consult with others during the posttest.

______740 Articulated Truck Power Train System Components andFunctions Posttest

Follow the instructions on the posttest.

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MATERIALS NEEDED

EXERCISE


735 Articulated Truck Power Train System Components and Functions Posttest

Directions: Match the component with the function by placing the letter next to the component.

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1. Transmission Oil Filter Bypass Valve

2. Rotary Actuator

3. Torque Converter Lockup Clutch Solenoid Valve

4. Torque Converter Inlet Relief Valve

5. Pressure Control Valve

6. Solenoid and Relief Valve Group

7. Selector and Pressure Control Valve

8. Upshift Solenoid

A. Controls transmission hydraulicsystem pressure

B. Controls oil flow to the transmissionclutches

C. Opens when the transmission oilfilter is plugged and allows oil fromthe pump to bypass the filter

D. Directs oil from the transfer gearpump to the transfer gear and theaxle differentials

E. Controls the modulation of lockupclutch engagement

F. Controls the position of the selectorspool

G. Ensures sufficient oil pressure in thetorque converter

H. Directs oil to the rotary actuator

740 Articulated Truck Selector and Pressure Control ValveComponent Identification Posttest



______740 Articulated Truck Selector and Pressure Control ValveComponent Identification Posttest

Identify the Selector and Pressure Control Valve components by listingthe letter designation of the components next to the appropriatecomponent names on the posttest.

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MATERIALS NEEDED

EXERCISE


Directions: Fill in the blanks next to the terms with the correct letter.

Main relief valve

Rotary selector spool

Priority reduction valve

Torque converter inlet relief valve

Neutralizer valve

Pilot oil pressure tap

Lubrication pressure tap

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GA

B

E

D

F

C

740 TRANSMISSIONSELECTOR VALVE GROUP

NEUTRAL

740 Articulated Truck Selector and Pressure Control Valve ComponentIdentification Posttest

740 Articulated Truck Pressure Control Valve OperationPosttest



______740 Articulated Truck Pressure Control Valve Operation Posttest

Follow the instructions on the posttest.

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MATERIALS NEEDED


EXERCISE

1. When a shift is started, pilot oil from the rotary selector spool flows through which passage.

A. 1B 2C. 3D. 8

2. When the clutch begins to fill, the oil pressure in the clutch is balanced against____________________.

A. Pilot pressure at the load piston (4)B. Force of spring (9)C. Force of springs (5)D. Slug (10)

3. The force of springs (5) and ___________________ control the amount of time for the clutch toreach maximum pressure.

A. Pilot pressureB. Pump pressureC. Force of spring (9)D. Size of the load piston orifice (7)

4. What controls the amount of time necessary for the clutch to release?

A. Force of springs (5)B. Decay orifice (6)C. Force of spring (9)D. Load piston orifice (7)

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740 Articulated Truck Pressure Control Valve Operation Posttest

Directions: Multiple Choice. Refer to the pressure control valve station graphic to answer thefollowing questions. Circle the correct letter(s) indicating the best answer(s) for each question.

4 5

79

8

2

6

10

31

TRANSMISSION PLANETARYVALVE STATION

service training 740 articulated truck

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