- Wheel Dozer
- 854K (S/N: KK61-UP; RM61-UP)
- Wheel Loader
- 988 (S/N: 87A1-UP)
- 988B (S/N: 50W1-UP)
- 988F (S/N: 8YG1-UP)
- 988F Series II (S/N: 2ZR1-UP)
- 988K (S/N: T8E1-UP; L8X1-UP; LWX1-UP; TWX1-UP)
- 990 (S/N: 7HK1-UP)
- 990 Series II (S/N: BCR1-UP; 4FR1-UP)
- 990H (S/N: BWX1-UP)
- 990K (S/N: DJK1-UP; A9P1-UP; M9P1-UP; K9X1-UP)
- 992 (S/N: 25K1-UP)
- 992B (S/N: 25K1-UP)
- 992C (S/N: 42X1-UP; 49Z1-UP)
- 992D (S/N: 7MJ1-UP)
- 992K (S/N: KK41-UP; RM51-UP)
- 993K (S/N: LWA1-UP; Z4D1-UP; Z8D1-UP; Z9K1-UP; Z4Z1-UP; Z8Z1-UP)
- 994 (S/N: 9YF1-UP)
- 994D (S/N: 3TZ1-UP)
- 994F (S/N: 4421-UP)
- 994H (S/N: DWC1-UP)
- 988B (S/N: 50W1-UP)
Introduction
The following instructions will describe the steps needed to repair cracks in lift arm crossmembers. Small surface casting cracks, known as hot tears, are inherent in the steel casting process, allowable up to 45 mm in length, and will not reduce the life of the casting. Weld repair of cracks less than
To check the length of the crack, or to see if the crack length increases, remove the paint around the crack and use dye to determine the length of the crack. Use a punch to mark the ends of the cracks to see if the cracks get longer. Cracks from
Safety
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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 Society2501 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 LaborWashington, 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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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 any Caterpillar dealer for replacement manuals. Proper care is your responsibility. For machines equipped with quick coupler, improper attachment of work tools could result in injury or death. Do not operate this machine until you have positive indication that the coupler pins are fully engaged. Follow recommended procedure in Operation and Maintenance Manual. Securely fasten radio (if equipped) and all loose items such as lunch boxes or tools. Failure to do so could allow items to shift position during rough machine operation or tip over and result in injury. Refer to the Operation and Maintenance Manual for specific fastening and latching requirements. |
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Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine. To prevent personal injury or death, perform the following: Park the machine on a smooth level surface. Lower the blade and or attachments to the ground. Stop the engine and engage the parking brake. Block the wheels and install the steering frame lock. Turn the battery disconnect switch to the OFF position and remove the key. Place a Special Instruction, SEHS7332, "Do Not Operate" tag at the battery disconnect switch location to inform personnel that the machine is being worked on. |
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Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin. At operating temperature, the engine coolant is hot and under pressure. Steam can cause personal injury. Check the coolant level only after the engine has been stopped and the cooling system pressure cap is cool enough to touch with your bare hand. Remove the cooling system pressure cap slowly to relieve pressure. Cooling system conditioner contains alkali. Avoid contact with the skin and eyes to prevent personal injury. |
To prevent personal injury or death, do not let engine fluids stay on your skin. Clean skin and nails using hand cleaner and wash with soap and water. Wash or discard clothing and rags contaminated with engine fluids.
Engine Fluids (Oil, Fuel and Coolant) are a threat to the environment. Properly recycle or dispose of engine fluids according to local regulations. Never put engine fluids in the trash, on the ground , in sewers or bodies of water.
Wear gloves and other protective gear while working with hot engine fluids. Use caution when draining hot engine fluids and avoid direct skin contact.
Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly. Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar is used, make sure that procedure is safe for you and for other people to use. Make sure that the product will not be damaged or the product will be made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.
Repair Procedure
- Clean the repair area surface to make sure that the area is free of oil, grease, paint, or scale.
- .The crossmember should be at a minimum temperature of
10 ° C (50° F) or more. - Use an arc air torch, or similar tool, to remove the complete crack. Extend the gouge
6 mm (0.25 inch) beyond each end of the crack. Make sure that the crack is removed completely but take care not to burn through the crossmember. If a hole develops through the crossmember, a back-up strip will have to be used. - Grind the gouged area to remove any debris and prepare the weld area such that a 45° to 60° included angle V-groove is formed.
- If the crack goes through the thickness of the crossmember, completely remove the crack . This action will cause an opening in the crossmember. A back-up strip of material, at least .
4775 mm (188 inch) thick, should be placed through the opening and tack welded in place. - Weld the area using one of the processed and filler metals listed in the chart. Weld in a horizontal position if possible.
Show/hide table
Table 1 Welding Process AWS Spec Electrode Designation SMAW
(Stick Welding)A5.1 E7018 or equivalent GMAW
(MIG Welding)A5.18 ER70S-3 or equivalent FCAW
(Gas Shielding)A5.20 E7OT-1*, E71T-1 ** * For welding horizontal and flat positions.
** For welding all positions. - Allow the weld to cool slowly between each pass. Do not allow the temperature to vary more than 100°F between passes. No matter which weld process is being used, maximize the number of passes and make sure the "weave" width of each weld pass is less than
12.7 mm (0.50 inch) . - Remove weld slag and clean the weld after each pass.
- When the welding process is completed, grind the repaired area smooth and flush with the casting surface. Make sure that the area is free of porosity, undercuts, or cracks. Avoid high grinding pressures that may cause excessive heat and discoloration of the weld material.
- Allow the weld to cool slowly at ambient air temperature.
- Peen the weld using a standard ball peen hammer. Coverage should be 100% to 200% of the surface. Do not peen more area than needed. (The peening improves the fatigue life of the crossmember.)