Procedure to Install an Updated Body Position Switch on Certain 773F and 775F Off-Highway Trucks{1408} Caterpillar

Off-Highway Truck/Tractor:

773F (S/N: EED1-UP; EXD1-UP)

Quarry Truck:

775E (S/N: DTE1-UP)

775F (S/N: EYG1-UP; DLS1-UP)

Introduction

ReferenceSpecial Instruction, REHS1841, "General Welding Procedures"

ReferenceOperation and Maintenance Manual, for your truck.

The following procedure describes the process of installing an updated body position switch onto certain Off-Highway Trucks. The new magnet and orientation of the switch will help to provide more reliable operation of the position switch.

Safety

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Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your Cat dealer for replacement manuals. Proper care is your responsibility.

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Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system. Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

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Personal injury or death can result from improper lifting or blocking. When a hoist or jack is used to lift any part or component, stand clear of the area. Be sure the hoist or jack has the correct capacity to lift a component. Install blocks or stands before performance of any work under a heavy component. Approximate weights of the components are shown. Clean all surfaces where parts are to be installed.

Required Parts

Machine Preparation

1. Move the machine to a hard level surface.

2. Avoid sudden steering inputs when you are parking the machine.

3. Apply the service brakes in order to stop the machine.

4. Move the transmission control lever to the PARK position.

5. Raise the body and install the retaining pins. Refer to Operation and Maintenance Manual, SEBU7837 for instructions on securing the truck body. Place the hoist control lever in the FLOAT position for at least 10 seconds.

6. Turn the engine start switch to the OFF position in order to stop the engine.

7. Turn the battery disconnect switch to the OFF position.

8. Disconnect the battery. Refer to Operation and Maintenance Manual, "Battery or Battery Cable - Inspect/Replace" for additional information disconnecting the battery.

9. Chock the front wheels and the rear wheels. Refer to Disassembly and Assembly, "Wheel Chock (Front and Rear) - Remove and Install".

10. Release the pressure from the system. Refer to Operations and Maintenance Manual, "System Pressure Release".

Removal Procedure

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Illustration 1	g02826216
Location of existing bracket

1. Cut the existing bracket off the body.

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Illustration 2	g02820723
View of the rear of the frame (A) Limit switch assembly (B) Bracket (C) Harness assembly

2. Disconnect limit switch assembly (A) from harness assembly (C) .

3. Remove limit switch assembly (A) and bracket (B) from the frame. Retain two 130-5300 Clips .

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Illustration 3	g02972217
View of the truck frame from the rear prior to the removal of the boss and lug

4. Remove one 9R-2613 Weld Boss and discard.

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Illustration 4	g02973487
(C) Maintain the same fore and aft position (D) 257-0417 Block (E) 80.5 mm (3.17 inch)

5. Mark a new location for the (D) toward the centerline of the truck using measurement (E). Maintain the same fore and aft location (C) .

6. Then remove one (D) by grinding out the welds that hold the block in place.

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Illustration 5	g02972218
(W1) 6 mm (0.236 inch) fillet welds.

7. Move the block (D) to the new location that was marked in Step 5, and tack weld the block in place. Then finish weld the block on two sides using 6 mm (0.236 inch) Fillet welds.

Fabrication Procedure

Fabricate the plate used for mounting the magnet to the body using 6.0 mm (0.236 inch) thick ASTM grade A36 or grade A370 carbon steel.

Illustration 6	g02968518
Typical view (1) Plate

Illustration 7	g02967676
Development view (1) Plate (A) 49 mm (1.93 inch) (B) 221.6 mm (8.72 inch) (C) 102 mm (4.02 inch)

Illustration 8	g02967976
(D) 75 mm (2.95 inch) (E) 20 ± 2 mm (0.787 ± 0.079 inch) Radius (F) 6 mm (0.236 inch) (G) 102 mm (4.02 inch) (H) 43 mm (1.7 inch) (J) 12 mm (0.47 inch) (K) 8 mm (0.315 inch) Radius (eight places) (L) 10 mm (0.394 inch) by 26 mm (1.024 inch) Slots (two places) (M) 25 mm (0.98 inch) (N) 50 mm (1.97 inch) (P) Radius (four places, two slots) (R) 90 mm (3.54 inch) (S) 43 mm (1.69 inch) (T) 163 mm (6.42 inch) (U) 50 mm (1.968 inch) (V) 102 mm (4.02 inch)

Installation Procedure

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Illustration 9	g02968518
Typical view (1) Plate

1. Fabricate one plate (1). Refer to ""Fabrication Procedure" ".

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Illustration 10	g02828559
(1) Plate

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Illustration 11	g02974680
(1) Plate (A) 10 ± 1 Degrees (B) 17 ± 2 mm (0.67 ± 0.07 inch) (C) 75 mm (2.95 inch) (D) 10 ± 1 Degrees (E) 300 ± 2 mm (11.81 ± 0.08 inch)

2. Position plate (1) on the plate assembly for the body. Refer to Illustration 10 and Illustration 11.

   Note: Measurement (A) is a 10 ± 1 Degree angle measured clockwise from a line that goes through the pivot bore and is parallel with the ground.

   Note: Measurement (B) locates the top of plate (1) .

   Note: Measurement (C) is a check for dimension (B). Measure down from the bottom of the body

   Note: Measurement (D) is a 10 ± 1 Degree angle measured clockwise from a line that goes through the center of the pivot bore and is perpendicular to the ground.

   Note: Measurement (E) locates the back edge of plate (1) .

3. Tack weld plate (1) in place.

   Note: Refer to Special Instruction, REHS1841, "General Welding Procedures" before performing any welding on the machine.

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Illustration 12	g02977698
(1) Plate (2) 5G-7820 Magnet As (3) 8T-7547 Bolt (4) 8T-4224 Hard Washer (5) 6V-9189 Locknut

4. Secure magnet assembly (2) to plate (1) by using two bolts (3), four hard washers (4), and two locknuts (5) .

   Note: Leave magnet assembly (2) loose for adjustment.

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Illustration 13	g02977659
View of the rear of the frame (D) Block (6) 378-9063 Plate (7) 8T-4136 Bolt (8) 8T-4121 Hard Washer (9) 130-5300 Clip (14) 132-5789 Clip

5. Secure plate (6) and two existing clips (9) and one clip (14) to block (D). Use two bolts (7), and two hard washers (8) .

   Note: Tighten bolts (7) to a torque of 55 ± 10 N·m (40.5 ± 7.4 lb ft).

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Illustration 14	g02977438
View of the rear of the frame (4) 8T-4224 Hard Washer (6) 378-9063 Plate (9) 130-5300 Clip (10) 228-4808 Position Switch Gp (11) 4M-6425 Bolt

6. Secure one position switch group (10) and one clip (9) to plate (6) by using two bolts (11) and two hard washers (4) .

   Note: Tighten bolts (11) to a torque of 25 ± 6 N·m (220 ± 55 lb in), and secure the connector for Position Switch Gp (10) in clip (9) .

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Illustration 15	g02977518
(E) Chassis harness assembly (9) 130-5300 Clip (10) 228-4808 Position Switch Gp (12) 383-2704 Switch Harness As connector (The harness is not shown.) (13) 7K-1181 Cable Strap (14) 132-5789 Clip

7. Connect switch harness assembly (12) to position switch group (10) and chassis harness assembly (E) .

8. Secure harness assembly (12) to clip (14) using cable strap (13) .

9. Secure the remaining chassis harness connectors to clips (9) .

10. Remove the body retaining pin and operate the hoist of the truck.

    Note: Refer to Operation and Maintenance Manual, SEBU7837 for instructions on removing the pins and operating the hoist.

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Illustration 16	g02977276
(E) Chassis harness assembly (G) 10 mm (0.394 inch) (2) 5G-7820 Magnet As (6) 384-4121 Plate (10) 228-4808 Position Switch Gp

11. With the body in the DOWN position, adjust magnet assembly (2) and position switch group (10) so that dimension (G) is 10 mm (0.394 inch).

    Note: Adjust plate (6) forward or backwards in order to achieve dimension 10 mm (0.394 inch).

12. Position magnet assembly (2) so that the body snubs at 203 to 254 mm (8 to 10 inch) between the front body pads and the frame rail.

    Note: If the truck body reaches the SNUB position too early, move magnet assembly (2) upward. If the truck body reaches the SNUB position too late, move magnet assembly (2) downward.

13. Tighten the hardware that secures magnet assembly (2) to a torque of 28 ± 7 N·m (250 ± 62 lb in).

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Illustration 17	g02979639
(1) Plate (W1) 6 mm (0.236 inch) Fillet weld

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Illustration 18	g02979439
(1) Plate (W2) 6 mm (0.236 inch) Flare-bevel groove weld

Note: Refer to Special Instruction, REHS1841, "General Welding Procedures" before performing any welding on the machine.

14. Finish weld plate (1) on three sides with a 6 mm (0.236 inch) fillet weld. Finish weld the front side of plate (1) with a 6 mm (0.236 inch) flare-bevel groove weld.

15. Clean and paint plate (1) and the welds.