Rework Procedure for Weld Crack on A-Pin Doubler Plate for Certain 966L, 966M, 972L, and 972M Medium Wheel Loaders {0679, 7054} Caterpillar

Wheel Loader

966L (S/N: FSL1-10685; FRS1-1961)

966M (S/N: MD71-193; EJA1-3181; DYC1-1387; R8D1-1253; LMM1-10386; KJP1-2977; L8R1-10271; GMS1-598)

966M Series XE (S/N: FL21-925; P6C1-1136; DZL1-289; B8P1-500; XCR1-333)

972L (S/N: RFB1-1412; YJW1-10241)

972M (S/N: A781-354; L8E1-1228; LSJ1-2602; GGN1-10279; WGN1-191; A8P1-1806; JPR1-959; M8W1-10265)

972M Series XE (S/N: AN31-356; L9S1-736; M5S1-365; EDW1-903; R1Z1-288)

Introduction

This Special Instruction provides the rework procedure to repair the weld cracks occurring on the weld joining the 464-7851 Tower As-RH and 464-7853 Plate As-LH, and on the weld joining the 464-7852 Tower As-RH and 464-7854 Plate As-LH on above listed machines.

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 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.

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Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.

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Failure to follow all safety guidelines prescribed in this document and by governing authorities and regulatory agencies may result in severe injury or death of personnel or machine damage.

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When removing a major component or attachment, ensure that it is properly blocked or secured before removing mounting hardware. An assembly that is disconnected without proper blocking may shift or fall, resulting in serious injury or death of personnel or machine damage.

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Personal injury or death can result from improper maintenance procedures. To avoid injury or death, follow the procedures exactly as stated below.

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Personal injury can result from improper handling of chemicals. Make sure you use all the necessary protective equipment required to do the job. Make sure that you read and understand all directions and hazards described on the labels and material safety data sheet of any chemical that is used. Observe all safety precautions recommended by the chemical manufacturer for handling, storage, and disposal of chemicals.

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Climbing equipment may be required to access this service point. Refer to the Operation and Maintenance Manual, "Mounting and Dismounting" topic for safety information.

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Before servicing/performing maintenance on the machine, electrical power must be physically disconnected; battery plugs must be disconnected from the batteries, or the trailing cable must be unplugged, and warning tags and padlocks shall be applied by a certified electrician. Certified electricians shall perform or direct any electrical work, including any energized testing, repair work in controllers, motors, or other approved compartments, and shall insure that all compartments are properly closed and inspected prior to re-energization. All applicable lock out and tag out procedures must be followed.

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Do not operate the machine if any guards or covers are missing or inadequately secured. Personnel could be seriously injured or machine damage may occur.

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Observe the safe working load limits of all lifting and blocking devices and keep a safe distance from suspended/blocked loads. Personnel may be seriously injured or killed by falling loads.

Machine Preparation

1. Park the machine on a flat surface.
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   Illustration 1	g06365673

2. Follow the safety procedures and raise the liftarm and secure using a vertical stand as shown in Illustration 1.
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   Illustration 2	g06367097
   Location of K-Pin

3. Remove the K-pin from the lower lifting cylinder to enable easy access for the rework.

4. Secure the bucket on a stand to avoid personal injury and machine damages.

5. Turn off the engine and remove the key from the starting switch.
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   Illustration 3	g00104545

6. Perform lockout tag out procedure by attaching a warning tag to the machine controls.

Installation Procedure

Illustration 4	g06365668
(A) Crack location

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Illustration 5	g06365766
(P1) Plate (D1) Angle is 45 degrees (D2) 12.0 mm (0.47 inch)

1. Grind the weld surface and remove the crack. Create a 45 degree bevel on thin doubler plate (P1) at a depth of 12.0 mm (0.47 inch).

   Note: The 45 degree wedge at the corner of plate (P1) doesn’t have to be a straight cut corner. It is acceptable to have slope, or be beveled, along the thickness of Plate (P1). The purpose of creating this wedge is to allow better weld penetration at this corner of weld joint.

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   Illustration 6	g06365890
   (P1) Plate

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   Illustration 7	g06366207
   (D3) 6.0 mm (0.23 inch) (D4) Angle is 45 degrees (D5) 6.0 mm (0.23 inch)

2. Create a 6.0 mm (0.23 inch) bevel on plate (P1) from point (C) to point (D). Refer to Illustration 7 for the dimensions.
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   Illustration 8	g06366255
   (P1) Plate (W1) 6.0 mm (0.24 inch) X 9.0 mm (0.35 inch) fillet weld with 9.0 mm (0.35 inch) leg on plate (P1) over 6.0 mm (0.24 inch) bevel weld (W2) 8.0 mm (0.31 inch) fillet weld over 12.0 mm (0.47 inch) bevel weld (W3) 8.0 mm (0.31 inch) fillet weld over 1.50 mm (0.059 inch) square groove weld

3. Weld the plate (P1) at the bevel using weld (W1) from point (C) to point (D). Weld the top area of plate (P1) using weld (W2). Use weld (W3) for smooth transitions to adjacent welds with the backside plate.
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   Illustration 9	g06366321
   (E) TIG Weld Toe Dress

4. Apply weld toe treatment (TIG Weld toe dress) on weld (W1) from point (C) to point (D).

5. Paint the repair areas to best match the color of what the existing frame has.