980M and 982M Wheel Loaders Power Train, Steering, Braking, Hydraulic, and Machine Systems Caterpillar

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Hot hydraulic oil under high pressure can remain in the components of the hydraulic system or the power train system after the engine has been stopped. The uncontrolled release of the hydraulic oil can cause sudden machine movement and can also result in the following conditions: Burns The penetration of body tissue Other personal injury Death If hydraulic oil penetrates body tissue, the injury must be treated immediately by a doctor who is familiar with this type of injury. Use a board or a piece of cardboard to check for a hydraulic oil leak. Make sure that all of the attachments have been lowered to the ground and that all trapped pressure has been released from the hydraulic system and the power train system. Also, make sure that the hydraulic oil is cool before the removal of any components or lines. Remove the hydraulic oil filler cap only when the engine is stopped and the filler cap is cool enough to touch with your bare hand.

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Personal injury or death can result from not engaging the parking brake. Transmission engagement alone will not prevent machine from rolling when the engine is stopped.

Specifications

Oil at Normal Operating Temperature

Stall Speed

Double Stall Speed

Introduction

This story includes the following tests:

• Transmission Clutch Solenoid Modulating Valve

• Transmission Clutch Pressure

• Lubrication Oil Pressure

• Torque Converter Outlet Pressure

• Transmission Oil Pump Pressure

• Torque Converter Inlet Pressure

This story includes the following adjustment procedures:

• Transmission Clutch Pressure

• Transmission Oil Pump Pressure

Required Tools

Illustration 1	g01106077
Tooling (A)

Illustration 2	g01623868
Tooling (B) 198-4240 Digital Pressure Indicator Gp

Reference: Refer to Tool Operating Manual, NEHS0818, "Using the 198-4240 Digital Pressure Indicator Group" for more information on using Tooling (B).

Machine Set Up

1. Park the machine on a smooth, level surface.

2. Place the transmission in the NEUTRAL position.

3. Lower the work tool to ground.

4. Engage the parking brake.

5. Place blocks in front of the wheels and behind the wheels.

6. Install the steering frame lock.
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   Illustration 3	g02735362

7. Perform machine walk-around and check for any leaks or damage. Check transmission oil level and fill to proper level if necessary.

8. Remove the front axle shafts and rear axle shafts except for stall tests.

9. Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.

10. Run the engine and warm the machine to operating temperatures. Engine coolant and hydraulic oil should at normal machine testing temperatures.

    Warm the transmission oil to normal operating temperature of approximately 83° ± 7°C (181° ± 12°F).

    Warm the torque converter oil to normal operating temperature of approximately 93° ± 17°C (199° ± 30°F).

    Reference: For more information about preparing a machine for troubleshooting, refer to the Service Manual module Testing and Adjusting, "Machine Preparation for Troubleshooting".

Location of Pressure Taps

Illustration 4	g03659147
Transmission clutch pressure taps are located on the left-hand side of the machine on the transmission. (1) Transmission pressure tap for clutch 1 "Reverse" (2) Transmission pressure tap for clutch 2 "Forward" (3) Transmission pressure tap for clutch 3 "Forth Speed" (4) Transmission pressure tap for clutch 4 "Third Speed" (5) Transmission pressure tap for clutch 5 "Second Speed" (6) Transmission pressure tap for clutch 6 "First Speed"

Illustration 5	g03659131
The remote pressure taps for the torque converter and the transmission are located on the right side of the machine under the cab. (7) Torque converter inlet pressure tap (8) Torque converter outlet pressure tap (9) Transmission lubrication pressure tap (10) Transmission pump pressure tap

Illustration 6	g03659165
Pressure tap "P3" for the lock up clutch is located on the left side of torque converter housing. (11) Lock up clutch pressure tap

Test for the Transmission Clutch Solenoid Modulating Valve

This test will determine whether the solenoid coil is energized and the solenoid plunger is shifting. The energized coil and shifted plunger will permit the flow of oil through the transmission clutch solenoid modulating valve.

Hearing the click of a solenoid to check that the solenoid coil is energized does not ensure that the solenoid plunger has shifted. Using a screwdriver to check that the solenoid coil is energized does not ensure that the solenoid plunger has shifted. The following test will determine if the solenoid plunger is shifting.

1. Perform the steps in the "Machine Set up" and then continue to the following steps.

2. Attach tooling (A) or (B) on pressure tap (1) through pressure tap (6).

3. Engage the parking brake. Shift the transmission to the NEUTRAL position. Start the engine and operate the engine at low idle.

4. Use the transmission neutralizer override switch in order to disengage the transmission neutralizer.

5. Depress the right service brake pedal and hold the right service brake pedal. Make sure that the machine is in FIRST SPEED. Release the parking brake. Watch the pressure gauge. Shift the transmission from the NEUTRAL position to the FORWARD position.

   The pressure on Number 2 clutch should rise. The pressure on the pressure gauge for the Number 6 clutch should rise. With the transmission in the FORWARD position, shift through the remaining forward speeds and return to the FIRST SPEED position. Use the transmission direction and speed control lever or the transmission upshift switch to change speeds. A pressure rise should be observed in each respective speed. This checks the operation of all the speed clutches.

6. Perform Step 5 for all reverse speeds. A pressure rise should be noted in all reverse speeds.

If a pressure rise is noted, the solenoid and the related electrical circuit are functioning.

If a pressure rise is not noted, use a screwdriver to check that the solenoid coil is energized. If the screwdriver is attracted to the solenoid coil, the attraction will indicate that the solenoid coil is energized. The problem is in the solenoid cartridge. The problem could be a bent solenoid stem, a screen that is dirty or plugged, or a spring that is weak or broken.

If the screwdriver does not indicate that the solenoid coil is energized, the problem is in the electrical circuit.

Reference: For additional information about calibrating the transmission clutch solenoid modulating valves, refer to the Service Manual module Testing and Adjusting, "Calibration and Programming" for the machine that is being serviced.

Reference: For additional information about calibrating the transmission clutch solenoid modulating valves, refer to the Service Manual module Testing and Adjusting, "Fill Time for the Transmission Clutch (Electronic Technician) - Calibrate" for the machine that is being serviced.

Test for Transmission Clutch Pressure

Use the following procedure to check the pressure of the direction clutch oil and the speed clutch oil.

1. Perform the steps in the "Machine Set Up" and then continue to the following steps.

2. Attach tooling (A) or (B) to each clutch pressure tap (1) through (6) and to the pump pressure tap (10).

3. Engage the parking brake. Shift the transmission to the NEUTRAL position. Start the engine and operate the engine at low idle.

4. Use the transmission neutralizer override switch in order to disengage the transmission neutralizer.

5. Depress and hold the right service brake pedal. Make sure that the machine is in FIRST SPEED. Release the parking brake. Watch the pressure gauges. Shift the transmission direction and speed control lever (if equipped) from the NEUTRAL position to the FORWARD position. Make sure that the transmission oil is at normal operating temperature. The pressure on Number 2 clutch should rise. The pressure on Number 6 clutch should rise. The difference in pressure between transmission pump at tap (10) and clutch (2) must be within the values in Table 1. The difference in pressure between transmission pump at tap (10) and clutch (6) must be within the values in Table 1.

   With the transmission in the FORWARD position, shift through the remaining forward speeds and return to the FIRST SPEED position. Use the transmission direction and speed control lever (if equipped) or the transmission upshift switch (if equipped) to change speeds. The pressure difference between transmission pump and each energized clutch must be within the values in Table 1. Use Table 6 in order to determine which clutches should be energized in each gear. Clutch (5) has two sets of limits. If the pressure difference between the transmission pump and clutch (5) are not within the first limits, compare the pressures of clutch (5) and clutch 5 gauge pressure limits in Table 1.

6. Perform Step 5 for all reverse speeds. Use Table 6 to determine which clutches should be energized in each gear. Clutch (5) has two sets of limits. If the pressure difference between the transmission pump and clutch (5) are not within the first set of limits, compare the reading of clutch (5) pressure to the clutch 5 gauge pressure limits in Table 1.

Adjustments for the Transmission Clutch Pressure

If the pressure difference between the transmission pump and one of the clutches is not within the values in Table 1, then transmission clutch valve may need replaced. After properly shutting down the machine, temporarily replace the valve and retest to see if the pressure is now within specification. If pressures are still out of specification after changing valves, the transmission may have an internal leak.

Clutch (5) has two sets of limits in Table 1 and only needs to fall within one of the two sets of limits. If the pressure drop between the transmission pump, clutch (5), and clutch 5 gauge are not within the limits of Table 1, temporarily replace the valve and retest to see if the pressure is now within specification. If pressures are still out of specification after changing valves, the transmission may have an internal leak.

Reference: For additional information about calibrating the transmission clutch solenoid modulating valves, refer to the Service Manual module Testing and Adjusting, "Fill Time for the Transmission Clutch - Calibrate" for the machine that is being serviced.

Reference: For additional information about electrical system troubleshooting, refer to the Service Manual module Testing and Adjusting, "Troubleshooting Diagnostic Codes" for the machine that is being serviced.

Test for the Lubrication Oil Pressure

Use the following procedure to check the pressure of the transmission lubrication oil.

The pressure tap for the transmission lubrication oil is located on the right side of the machine under the cab behind an access panel. Refer to Illustration 6.

1. Perform the steps in the "Machine Set Up" and then continue to the following steps.

2. Attach tooling (A) or (B) on pressure tap (9).

3. Start the engine and operate the engine at high idle with transmission in neutral. Observe the pressure gauge. With the oil at normal operating temperature, the lubrication oil pressure must be within the values in Table 1.

Test of the Torque Converter Outlet Pressure

1. Perform the steps in the "Machine Set Up" and then continue to the following steps.

2. Attach tooling (A) or (B) on pressure tap (8).

3. Start the engine and operate the engine at high idle and transmission in neutral. Observe the pressure. With the oil at normal operating temperature, the torque converter outlet pressure must be within the values in Table 1.

Adjustment For The Torque Converter Outlet Pressure

1. Remove cover (12) from torque converter outlet relief valve (13).

   Note: Remove the cover slowly in order to keep the spring in the housing.

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   Illustration 7	g03659168
   (12) Cover (13) Torque converter outlet relief valve

2. Remove spring (16) and spacers (15) from spool (14) within the valve.
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   Illustration 8	g03627336
   Torque Converter Outlet Relief Valve (12) Cover (14) Relief valve spool (15) Spacers (16) Spring

3. Add or remove spacers (15) from the pack of springs in order to attain the desired pressure.
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   Table 7

   Spacers
   Pressure Change for the Valve(1)
   Description	Thickness	Pressure Change	Location of Spacers
   4M-1751 Spacer	0.41 mm (.016 inch)	19 kPa (2.7 psi)	Outlet relief valve
   5S-7001 Spacer	0.91 mm (.036 inch)	40 kPa (6 psi)

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   (1)	Result of the addition of one spacer or the removal of one spacer to the valve.

4. Install spacers (15) and spring (16).

5. Install cover (12) and tighten the bolts.

Torque Converter Stall and Implement Pump Double Stall - Test

The following procedure is used in order to test the torque converter stall test.

Note: Insure that the transmission oil is at normal operation temperature. Machines operating under normal conditions should have engine stall speeds that are within the specified range. Refer to the factory test measurements in order to determine the appropriate specification for the machine that is being serviced. If the machine that is being serviced is outside the range of engine stall speeds, the power train components should be inspected. Use the component test specifications in order to determine the corrective action. These ranges of engine stall speed should not be used to adjust the engine power of the machine. If engine output is suspect, the engine should be tested on a dynamometer.

The torque converter stall test helps determine if the engine is producing the correct power output. The torque converter stall test provides an engine speed for comparison with the torque converter stall speed that is measured at the factory. The engine stall speed should be in the range that is shown.

The torque converter stall test helps determine if the engine is producing the correct power output. This stall test is used in many diagnostic procedures.

The parking brake must be applied when the tests are performed. Make sure that the parking brake is fully operational before you perform any tests.

The service brakes must be applied when the tests are performed. Make sure that the service brakes are fully operational before you perform any tests.

Machine Preparation

1. Position the machine on a smooth horizontal location.

2. Ensure that the parking brake is engaged. Apply service brake during test.

Test Procedure for Torque Convertor Stall

1. Run the engine and warm the machine to operation temperatures. Engine coolant and hydraulic oil should be at normal machine testing temperatures.

   Note: Warm transmission oil and torque converter oil to the temperatures listed in table.

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   Table 8

   Oil at Normal Operating Temperature
   Transmission Oil	Torque Converter Oil
   83° ± 7°C (181° ± 12°F)	93° ± 17°C (199° ± 30°F)

   • Fully apply parking brake and service brake. Select manual shift mode. Shift transmission to FOURTH SPEED, NEUTRAL.

2. Shift the transmission to FOURTH SPEED, FORWARD, and press throttle pedal to 100%.

3. A warning indicating that the machine is in gear with parking brake applied will appear on the display.

4. Once the engine speed stabilizes, record engine speed.

5. Shift the transmission to FOURTH SPEED, NEUTRAL, and release throttle pedal.
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   Table 9

   Stall Speed
   Stall speed for the 980M		Stall speed for the 982M
   Economy Mode Off 1973 +10/ -50 rpm		Economy Mode Off 1847 +10/- 50 rpm

   If the torque converter stall speed is too high, the engine power output could be too high. (Not likely)

   If the torque converter stall speed is too low, the engine may not be developing full power. There may be a parasitic load on the engine.

Test Procedure for Torque Convertor Double Stall

1. Run the engine and warm the machine to operation temperatures. Engine coolant and hydraulic oil should be at normal machine testing temperatures.

   Note: Warm transmission oil and torque converter oil to the temperatures listed in table.

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   Table 10

   Oil at Normal Operating Temperature
   Transmission Oil	Torque Converter Oil
   83° ± 7°C (181° ± 12°F)	93° ± 17°C (199° ± 30°F)

   • Fully apply parking brake and service brake. Select manual shift mode. Shift transmission to FOURTH SPEED, NEUTRAL.

2. At low idle shift the transmission to FOURTH SPEED, FORWARD.

3. Fully place the bucket in the racked back position.

4. Place engine in HIGH IDLE.

5. Stall tilt fully in the racked back position, and command full lift.

6. Once the engine speed stabilizes, Record the stabilized engine speed that occurs when the lift cylinders are extending.

7. Shift the transmission to FOURTH SPEED, NEUTRAL, and release throttle pedal.
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   Table 11

   Double Stall Speed
   Stall speed for the 980M		Stall speed for the 982M
   Economy Mode Off 1418 +150/- 100 rpm		Economy Mode Off 1451 +150/- 100 rpm

   If the torque converter double stall speed is too high, the engine power output could be too high. (Not likely)

   If the torque converter double stall speed is too low, the engine may not be developing full power. There may be a parasitic load on the engine.

Transmission Oil Pump Pressure

Illustration 9	g03672329
Electronic Main Relief Valve (eMRV) is located on the left side of torque converter housing. (17) Electronic Main Relief Valve (eMRV)

The electronic main relief valve (eMRV) is what controls the "pump pressure". The machine uses an electronically controlled (eMRV) which is controlled by the transmission ECM. The pump pressure, which is controlled by the (eMVR), will automatically increase if the transmission software detects that the pressure is too low.

If the measured pump pressures do not meet specification, temporarily replace the (eMRV) and repeat the test through Cat ET. If the measured pump pressures are still NOT within specification after replacing the (eMRV), the transmission pump may need checked.

Test for the Transmission Oil Pump Pressure

1. Before checking the Transmission Oil pump Pressure, verify the transmission neutral clutch solenoid modulating valve is functioning.

   Reference: Refer to the section "Test for the Transmission Clutch Solenoid Modulating Valve" in this document for the proper procedure.

   Also, verify the pressure difference between the transmission pump and the transmission neutral clutch is within specification.

   Reference: Refer to the section "Test for the Transmission Clutch Pressure" in this document for the proper procedure.

2. Perform the steps in the "Machine Set Up" and then continue to the following steps.

3. Attach tooling (A) or (B) on pressure tap (10).

4. Connect the machine to a laptop computer equipped with the latest version of Caterpillar Electronic Technician Cat ET. Establish communication.

5. In Cat ET, navigate to the "Diagnostics" drop-down menu and select "Diagnostics Tests". Expand the "Transmission ECM" section under "Available ECM(s)" and select "Transmission Main Relief Valve Test".

6. Follow the on-screen instructions through Cat ET to complete the pressure test. The test will automatically command the engine to a predefined speed and ask if the measured pressure is within certain limits for several test points.

Test for the Torque Converter Inlet Pressure

1. Perform the steps in the "Machine Set Up" and then continue to the following steps.

2. Attach tooling (A) or (B) on pressure tap (7).

3. Start the engine and operate the engine at high idle with transmission in neutral. Observe the pressure. With the oil at normal operating temperature, the torque converter inlet pressure must be within the values in Table 1.

Torque Converter Lockup Clutch Pressure - Test

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before moving the machine to perform the test that follows.

Lockup Clutch Engaged (Maximum stabilized pressure)

Note: This test is performed while moving the machine. Ensure test area is safe to operate.

1. Install test equipment to test port (11).

2. Enable lockup clutch in Second gear

3. Engage the parking brake.

4. Move the transmission direction control switch to the NEUTRAL position. Start the engine.

5. Apply the service brakes and release the parking brake

6. Release service breaks.

7. Place the transmission in SECOND SPEED forward.

8. Move the transmission direction control switch to the FORWARD position.

9. Increase the engine speed to high idle.

10. Operate the machine at maximum speed and observe the pressure reading on the gauge. Make sure that the left service brake pedal or the right service brake pedal are not depressed. If the left service brake pedal or the right service brake pedal are depressed, the lockup clutch will not engage. The maximum stabilized pressure must be 2450 ± 150 kPa (355 ± 22 psi).

Note: In the current software, the Lock up torque converter (LUC) is calibrated within the transmission fill calibration.