Procedure to Update the Operator Walkway Mounting on Certain 793D Off-Highway Trucks {0679, 7253, 7255, 7256, 7277, 7319} Caterpillar

Off-Highway Truck/Tractor

793D (S/N: FDB1-UP)

Introduction

This special Instruction will cover the procedure to update the operator walkway mounting on machine listed above.

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

Safety Section

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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 operating the machine.

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When it is necessary to work under the machine with the body (bed) raised, attach the body (bed) retaining cable to the rear tow point. Install the rear tow point pin through the end of the retaining cable. Failure to properly secure the body (bed) may result in personal injury or death.

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Falling Hazard. May cause personal injury or death. Always attach safety lanyard to appropriate fixing point.

Note: Permit only one operator on the machine. Either keep other personnel away from the machine, or keep other personnel in the sight of the operator.

Move the machine to a smooth horizontal location.

Move away from any machines that are working and any personnel.

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 to stop the machine.

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

5. If the body is fully lowered, place the hoist control lever in the FLOAT position for at least 10 seconds.

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

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

8. Disconnect the battery. Refer to Special Instruction , SEHS7633 , "Battery Maintenance Procedure" for additional information on the battery.

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

Note: A 4C-8370 Thread Repair Assembly may be used on any original mounting blocks that have been previously damaged.

Required Parts

Catwalk / Mirror Assembly Rework Procedure

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Illustration 1	g06104283
(A) Handrail assembly (B) Fender group (C) Air cleaner group

1. Remove and retain handrail assembly (A), fender group (B), air cleaner group (C) and associated hardware.

   The weight of the handrail assembly (A) is approximately 54.66 kg (120.50 lb).

   The weight of the fender group (B) is approximately 62.788 kg (138.424 lb).

   The weight of the air cleaner group (C) is approximately 48.725 kg (107.420 lb).

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   Illustration 2	g06104287
   (D) Mirror mounting support assembly (E) ISO mount (F) Sleeve

2. Remove and discard mirror mounting support assembly (D). Retain ISO mount (E) and sleeve (F) from cab mounts.
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   Illustration 3	g06104293
   (G) Front catwalk assembly (H) Side catwalk assembly

3. Remove and retain front catwalk assembly (G), side catwalk assembly (H) and all associated hardware's.

   The weight of the front catwalk assembly (G) is approximately 132.5 kg (292.1 lb).

   The weight of the side catwalk assembly (H) is approximately 104.7 kg (230.8 lb).

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   Illustration 4	g06104294

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   Illustration 5	g06104263
   View of area J (K) 6.0 mm (0.24 inch) (1) 8X-7175 Bar (W1) 3.0 mm (0.12 inch) fillet weld on both sides (L) 21.0 mm (0.83 inch)

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   Illustration 6	g06104274
   Dealer fabricated (1) 8X-7175 Bar (M) 125 mm (4.9 inch) (N) 70 mm (2.8 inch) (P) 14.0 mm (0.55 inch) (R) 20.0 mm (0.79 inch) (S) 14.0 mm (0.55 inch) (T) 40 mm (1.6 inch)

   Note: Clean and prepare the Cab front channel areas to be welded. Remove all paint, dirt, oil, debris, weld, and weld spatter. Fill gouges with weld and grind smooth prior to channel installation.

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

4. weld bar (1) as per the dimension shown in Illustration 5.
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   Illustration 7	g06104318
   (G) Front catwalk assembly

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   Illustration 8	g06104266
   View of area U (V) 37.0 mm (1.46 inch) (X) 112.0 mm (4.41 inch) (Y) 70.0 mm (2.76 inch) (Z) 2 slot of dimension 14.0 mm (0.55 inch) X 24.0 mm (0.94 inch)

5. Cut two slots in front catwalk (G) as per dimension shown in Illustration 8.
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   Illustration 9	g06104312
   Bottom view of Front catwalk assembly (G) ( 2) 480-6847 Plate As

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   Illustration 10	g06104279
   (2) 480-6847 Plate As (W2) 3.0 mm (0.12 inch) fillet weld (25 - 75) (AC) 11.0 mm (0.43 inch) (AD) 50.0 mm (1.97 inch) (W3) 3.0 mm (0.12 inch) fillet weld on both ends

6. Weld plate assembly (2) with Front catwalk as per dimension shown in Illustration 10.
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   Illustration 11	g06104317
   Bottom view of side catwalk assembly (H) ( 3) 481-7891 Plate (AE) Bracket assembly

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   Illustration 12	g06104285
   (3) 481-7891 Plate (W4) 3.0 mm (0.12 inch)fillet weld (25 - 75) (W5) 3.0 mm (0.12 inch)fillet weld on both ends (AF) 56.0 mm (2.20 inch)

7. Weld Plate (3) with Side catwalk as per dimension shown in Illustration 12.
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   Illustration 13	g06104262
   (AE) Bracket assembly (AG) 50.0 mm (1.97 inch) (AH) 50.5 mm (1.99 inch) (AJ) 4 slots of dimension 13.5 mm (0.53 inch) X 24.0 mm (0.94 inch) (AK) 100.0 mm (3.94 inch) (AL) 117 mm (4.61 inch)

8. Cut four slots in side catwalk bracket assembly (AE) as per dimension shown in Illustration 13.
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   Illustration 14	g06104298
   (G) Front catwalk assembly

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   Illustration 15	g06104338
   View of area AM (4) 332-8888 Spacer (5) 8T-8919 Bolt

9. Secure modified front catwalk (G) onto cab frame using Spacer (4) and bolt (5) as shown in Illustration 15.
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   Illustration 16	g06104299
   (G) Front catwalk assembly (H) Side catwalk assembly

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   Illustration 17	g06104256
   View of area AN (4) 332-8888 Spacer (6) 8T-4184 Bolt

10. Secure modified side catwalk to cab side frame using spacer (4) and bolt (6) as shown in Illustration 15.
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    Illustration 18	g06104300
    Bottom view (LH) (AE) Bracket assembly

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    Illustration 19	g06104258
    View of area AP (7) 091-9035 Spacer (8) 4L-9337 Bolt (9) 7X-0288 Bolt

11. Secure catwalk bracket assembly (AE) using spacer (7), bolt (8) and bolt (9) as shown in Illustration 19.
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    Illustration 20	g06104332
    (G) Front catwalk assembly (H) Side catwalk assembly (10) 480-6835 Plate As (11) 259-8137 Hard Washer (12) 118-7313 Bolt (13) 480-6844 Plate As (14) 480-6840 Plate As (AR) 483-0738 Catwalk Mounting Group

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    Illustration 21	g06104291
    Bottom View (AR) 483-0738 Catwalk Mounting Gp (4) 332-8888 Spacer (15) 332-5856 Spacer (16) 8T-6466 Bolt (17) 8T-4194 Bolt

12. Assemble new mirror mounting support group with the above mentioned hardware's as shown in Illustration 20 and Illustration 21.
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    Illustration 22	g06104323
    (E) 163-0042 Mount (F) 163-3127 Sleeve (AR) 483-0738 Catwalk Mounting Gp (AS) Cab Mounting Group (AT) 5T-5807 Retainer (AU) 1K-9402 Bolt

    Note: Check ISO mounts (E), sleeves (F), retainer (AT), and bolt (AU) are in good condition, or else replace with new hardware's.

13. Secure catwalk mounting to the cab front left ROPS location using ISO mount (E), sleeve (F), retainer (AT), and bolt (AU) that were saved in Step 3. Refer to Illustration 22.
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    Illustration 23	g06104330
    (H) Side catwalk assembly

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    Illustration 24	g06104260
    View of area AV (4) 332-8888 Spacer (17) 8T-4194 Bolt

14. Secure side catwalk with new mirror mounting support group using spacer (4) and bolt (17) as shown in Illustration 24.
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    Illustration 25	g06104306
    (A) Handrail assembly (B) Fender group (C) Air cleaner group

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    Illustration 26	g06104261
    View of area AX (18) 483-0737 Plate (* Shim plate based on requirement) (19) 198-4778 Hard Washer (20) 8T-4910 Bolt

15. Secure fender group (B), air cleaner group (C), handrail group (A) with associated hardware's that were saved in Step 1. Refer to Illustration 25.

    Note: As required, use the following shim plate (18).

16. Secure mirror post along with new mirror mounting support group along with plate (18) using washer (19) and bolt (20) as shown in Illustration 26.