Weld Repair Instructions for the Cab{7301} Caterpillar

Track-Type Tractors:

D6H Series II (PIN: 8FC4000-UP; 3YG4000-UP; 5HF4000-UP; 4GG4000-UP; 4RC4000-UP; 4LG4000-UP; 2KD4000-UP; 1FJ4000-UP; 3ED4000-UP; 3ZF4000-UP; 6CF4000-UP; 4YF4000-UP; 6FC4000-UP; 2TG4000-UP; 1KD4000-UP; 5KK1-UP; 2BL1-UP; 7ZK1-UP; 9KJ1-UP; 9LK1-UP; 8SK1-UP; 2DK1-UP; 6CK1-UP; 1YL1-UP; 2TL1-UP; 8ZJ1-UP; 8KK1-UP; 9RK1-UP)

D7H Series II (PIN: 4AB4000-UP; 5BF4000-UP; 4FG4000-UP; 2RG4000-UP; 2SB4000-UP; 5WB4000-UP; 3XG4000-UP; 79Z4000-UP; 80Z4000-UP; 82Z4000-UP)

Introduction

This instruction provides the procedure for repairing cracks that form in the cab. The procedure requires grinding cracks, welding cracks and plates, and fabricating reinforcement plates.

During conditions of high bending and impact loads, cracks can form on the structure of the cab. The cracks can propagate during normal operating conditions.

Identify the crack location. Refer to ""Location of Crack" ". Then complete the procedure for repair of the identified location.

After the procedure is completed, prepare the machine for operation. Refer to the machine's Operation and Maintenance Manual for instructions.

Warnings

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Do not attempt to assemble this machine until you read and you understand the assembly instructions. Improper assembly procedures could result in injury or death.

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Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, turn the battery disconnect switch to the OFF position. Remove the key for the battery disconnect switch. Use a secure padlock in order to lock the battery compartment access door. 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 can result from flame cutting or welding on painted areas. The effect of gasses from burned paint is a hazard to the person doing the cutting or welding. Do not flame cut or weld on painted areas.

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Personal injury or death can result from fumes, gases and ultraviolet rays from the weld arc. Welding can cause fumes, burn skin and produce ultraviolet rays. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing area. Wear eye, ear and body protection before working. Protect yourself and others; read and understand this warning. Fumes and gases can be dangerous to your health. Ultraviolet rays from the weld arc can injure eyes and burn skin. Electric shock can cause death. Read and understand the manufacturer's instructions and your employer's safety practices. Do not touch live electrical parts. See "American National Standard Z49.1, Safety in Welding and Cutting" published by the American Welding Society. American Welding Society 2501 N.W. 7th Street Miami, Florida 33125 See "OSHA Safety and Health Standards, 29 CFR 1910", available from U.S. Department of Labor. U.S. Department of Labor Washington, D.C. 20210

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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.

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NOTICE
Avoid using excessive heat when you are welding. Excessive heat can cause the components to bend.

Locations of Cracks

Illustration 1	g00470376
Locations (1) Top of Vertical Support (2) Top of Side Window (Rear) (3) Corner Between Rear Window and Side Window (4) Cab Mounting Bolt (Hole) (5) Bottom of Vertical Support (6) Inside Support for Door

General Repair Procedure

1. Remove items from the cab that can be damaged by heat, arcs, and slag. Remove the following items or protect the items.
   • Headliners

   • Compartments

   • Covers

   • Wires

   • Windows

   • All other items that could be damaged

   Note: The heat and the sparks that are produced during welding can damage the glass. If the windows are not removed, protect the glass.

2. Use a small grinder to vee out the crack.

   Note: Other methods of grinding could cause damage to the structure.

Note: Do not weld on parts that have a temperature less than 16°C (60.8°F).

3. Clean all locations that will contain welds. Remove oils, moisture, grease, rust, paint, or any other contaminants from the locations that will contain welds.

4. Place a weld at the crack locations. Use metal inert gas welding (MIG).
   • 1.14 mm (0.045 inch) solid wire

   • Shield with 75 percent Argon

   • Shield with 25 percent Carbon Dioxide (CO₂)

5. Grind the welds until the surface is smooth and the surface blends into the structure.

Procedures

Top of Vertical Support

Illustration 2	g00470381
RH side

Illustration 3	g00470383
LH side

1. Complete ""General Repair Procedure" " for the locations of the cracks.

Top of Side Window (Rear)

Illustration 4	g00470384
RH side

Illustration 5	g00470385
LH side

1. Complete ""General Repair Procedure" " for the locations of the cracks.

2. Place welds between the locations that were skip welded.
   • The weld should be continuous and the weld should extend from the vertical support to the rear corner.

Corner Between Rear Window and Side Window

Illustration 6	g00470407
RH side (HH) 254 mm (10.0 inch) (WW) 3.0 mm (0.11 inch) Weld

Illustration 7	g00470408
LH side

1. Complete ""General Repair Procedure" " for the locations of the cracks.

2. Place two vertical welds (WW) between the locations that were skip welded.
   • The weld should be continuous and the weld should extend a minimum distance (HH) from the top.

   • Make sure that there is good fusion at the ends of each weld.

Cab Mounting Bolt (Hole)

Illustration 8	g00470409
RH side

Illustration 9	g00470410
LH side

1. Complete ""General Repair Procedure" " for the locations of the cracks.

Bottom of Vertical Support

Necessary Parts

Table 1

Necessary Parts
Item	Part Number	Description	Qty
10	9X-2045	Screws	2

Procedure

Illustration 10	g00470413
RH side

Illustration 11	g00470414
LH side

1. Complete ""General Repair Procedure" " for the locations of the cracks.

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Illustration 12	g00470424
Support for RH side (7) Support (B) 60° Angle (C) 140.0 mm (5.51 inch) (D) 45.0 mm (1.77 inch) Radius (E) 74.0 mm (2.91 inch) (F) 45.0 mm (1.77 inch) Diameter (G) 43.0 mm (1.69 inch) (H) 60.0 mm (2.36 inch) (I) 150 mm (5.91 inch) (J) 5.0 mm (0.20 inch) with 45° Angle (two locations) (K) 25.0 mm (0.98 inch) (L) 11.0 mm (0.43 inch) (M) 36.5 mm (1.44 inch) (N) 137.0 mm (5.39 inch) (P) 43.0 mm (1.70 inch) (R) 6.1 mm (0.24 inch) (S) 35.1 mm (1.38 inch) (T) 85.8 mm (3.38 inch) (V) 12.0 mm (0.47 inch) Diameter (two holes) (W) 200.0 mm (7.87 inch) (X) 5.0 mm (0.20 inch) (Y) 10.0 mm (0.39 inch) Radius (Z) 200.0 mm (7.87 inch) (BB) Chamfer the entire side of the plate. The angle is shown in view A-A.

2. Fabricate support (7). Support (7) will be used for the RH side.

   1. Use structural steel with a thickness of 5 mm (0.1875 inch).

   2. Fabricate the steel to the dimensions that are shown in Illustration 12.

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Illustration 13	g00470508
Support for LH side (8) Support (B) 71.9 mm (2.83 inch) (C) 45.0 mm (1.77 inch) Radius (D) 45.0 mm (1.77 inch) Diameter (E) 140.0 mm (5.51 inch) (F) 60° Angle (G) 5.0 mm (0.20 inch) with 45° Angle (two locations) (H) 150.0 mm (5.91 inch) (I) 60.0 mm (2.36 inch) (J) 43.0 mm (1.69 inch) (K) 36.5 mm (1.44 inch) (L) 25.0 mm (0.98 inch) (M) 11.0 mm (0.43 inch) (N) 137.0 mm (5.39 inch) (P) 200.0 mm (7.87 inch) (R) 200.0 mm (7.87 inch) (S) 10.0 mm (0.39 inch) Radius (T) 5.0 mm (0.20 inch) (BB) Chamfer the entire side of the plate. The angle is shown in view A-A.

3. Fabricate support (8). Support (8) will be used for the LH side.

   1. Use structural steel with a thickness of 5 mm (0.1875 inch).

   2. Fabricate the steel to the dimensions that are shown in Illustration 13.

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Illustration 14	g00484962
RH side (7) Support

4. Remove the retainer and remove the strap.

5. Position support (7) onto the vertical support.

   1. Carefully align support (7) around the fasteners and other features.

   2. Tack weld support (7) to the vertical support.

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Illustration 15	g00470511
RH side (7) Support (10) Screws (WW) 3.0 mm (0.11 inch) Weld

6. Place welds (WW) between support (7) and the vertical support.

Note: Screws (10) are longer than the existing screws in order to accommodate the plate thickness. Refer to ""Necessary Parts" ".

7. Replace the retainer and replace the strap. Use two screws (10) .

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Illustration 16	g00470513
LH side (8) Support (WW) 3.0 mm (0.11 inch) Weld

8. Position support (8) onto the vertical support.

   1. Carefully align support (8) around the fasteners and the other features.

   2. Tack weld support (8) to the vertical support.

9. Place welds (WW) between support (8) and the vertical support.

Inside Support for Door

Illustration 17	g00470515
RH side

Illustration 18	g00470514
LH side

1. Complete ""General Repair Procedure" " for the locations of the cracks.

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Illustration 19	g00470517
(9) Fabricated plate (BB) 150.0 mm (5.91 inch) (CC) 75.0 mm (2.95 inch) (DD) 22.0 mm (0.87 inch) (EE) 3.0 mm (0.11 inch) (FF) 5.0 mm (0.20 inch) (GG) 22.0 mm (0.87 inch)

2. Fabricate two plates (9) .

   1. Use structural steel with a thickness of 3 mm (0.11 inch).

   2. Fabricate the steel to the dimensions that are shown in Illustration 19.

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Illustration 20	g00470518
(9) Fabricated plate (WW) 3.0 mm (0.11 inch) Weld

Note: Allow sufficient space for reinstalling the seal for the door.

3. Position plate (9) onto the support for the door. Refer to Illustration 20.

4. Place welds (WW) between the support for the door and plate (9). Place the weld along the edges of the plate. The edges are identified in Illustration 20.

5. Repeat Steps 3 and 4 for the other side of the machine.