2013/08/28 Caterpillar

Off-Highway Truck:

785C (S/N: APX1-UP)

Description of Change: A new rear access group is now used on the 785C Off-Highway Truck

The new ladder group includes extra mounting. The extra mounting on the ladder group will help to provide longer service life for the ladder group.

Adaptable To: The 187-0425 Ladder As has been replaced in production with the new 423-1720 Ladder As .

The new 423-1720 Ladder As is adaptable to (S/N: APX1-2338).

The new 423-1720 Ladder As is effective with (S/N: APX2339-UP).

Safety

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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.

Required Parts

Prepare the Machine

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.

1. Move the machine to a smooth horizontal location. Move away from any machines that are working and any personnel.

2. Move the transmission control to the P position and engage the parking brake.

3. Fully raise the truck body and install the truck body retaining cable. Move the hoist control to the FLOAT position until the cable is tight, then move the hoist control to the HOLD position.

   Refer to Operation and Maintenance Manual, "Cable (Truck Body Retaining)"

4. Stop the engine.

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

Note: Customers/Installers may require a suitable manlift or approved portable type access platform to assist in the installation.

Removal Procedure

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Illustration 1	g03425015
(A) Ladder group (B) Bolt (C) Washer

1. Attach a suitable lifting device to ladder group (A).

   Note: The approximate weight of ladder group (A) is 16 kg (35 lb).

2. Remove eight bolts (B) and eight washers (C) that secure ladder group (A) to the frame. Remove ladder group (A). Retain bolts (B) and washers (C). Discard ladder group (A) .

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Illustration 2	g03425045
(D) Block

3. Remove blocks (D). Grind the area smooth. Discard blocks (D) .

Fabrication Procedure

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

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Illustration 3	g03425019
(1) 5T-6229 Block

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Illustration 4	g03425076
Top view (1) 5T-6229 Block (AA) 418 ± 3 mm (16.45 ± 0.118 inch) (AB) 47 ± 3 mm (1.85 ± 0.118 inch)

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Illustration 5	g03425022
Rear view (1) 5T-6229 Block (AC) 349 ± 3 mm (13.74 ± 0.118 inch)

1. Locate three blocks (1) onto the rear support on the frame. Refer to Illustration 3, Illustration 4, and Illustration 5.

   Note: The new 423-1720 Ladder As should also be used to help locate blocks (1) .

   Note: Two blocks (1) that are located on the rear of the rear support should be horizontally level with the matching blocks on the left-hand side.

2. Prepare the area to be welded. Remove all paint, debris, dirt, or oil from the area.

3. Weld three blocks (1) onto the rear support on the frame.

   Note: Repaint the areas, as needed.

Installation Procedure

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Illustration 6	g03425500
(2) 423-1720 Ladder As (3) 8T-2502 Bolt (4) 8T-4896 Hard Washer

1. Attach a suitable lifting device to ladder assembly (2) and position ladder assembly (2) onto the rear support.

   Note: The approximate weight of ladder assembly (2) is 22 kg (48 lb).

2. Secure ladder assembly (2) to the rear support by using eight retained bolts (B), eight retained washers (C), two new bolts (3), and two new hard washers (4) .