Rear Frame Trunnion Support Weld Repair Procedure{7051} Caterpillar

Wheel Dozer:

854K (S/N: H9K1-UP; H8M1-UP; 2211-UP)

Wheel Loader:

992K (S/N: H4C1-UP; ZMX1-UP; 8801-UP)

Introduction

This Special Instruction describes the procedure for repairing weld cracks in the axle trunnion mount area on certain 992K Wheel Loader or 854K Wheel Dozer Engine End Frames.

Do not perform any procedure in this publication or order any parts until you understand the information that is contained in this publication.

Safety

Show/hide table

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

Show/hide table

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.

Show/hide table

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.

Reference

ReferenceSpecial Instruction, REHS1841, "General Welding Procedures"

ReferenceDisassembly and Assembly, RENR8912, "Tire and Rim (Rear) - Remove and Install"

ReferenceDisassembly and Assembly, RENR8912, "Oscillating Axle (Rear) - Remove"

ReferenceDisassembly and Assembly, RENR8912, "Oscillating Axle (Rear) - Install"

Welding Information

Refer to Table 1 for Caterpillar recommended welding processes and electrodes.

ReferenceSpecial Instruction, REHS1841, "General Welding Procedures"

Required Parts

Procedure to Weld Repair and Post Treat Rear Trunnion Casting Welds

Prepare the machine for rework. Refer to:

• Disassembly and Assembly, RENR8912, "Tire and Rim (Rear) - Remove and Install"

• Disassembly and Assembly, RENR8912, "Oscillating Axle (Rear) - Remove"

Illustration 1	g03395056
992K EEF Rear Trunnion Casting

Illustration 2	g03395058
Rear trunnion welds possible weld crack location

Repair Casting Weld Cracks

Illustration 3	g03395060
Area that is subject to weld cracks around casting

Illustration 4	g03395063
Final Weld Geometry (C) Doubler Plate (D) 12 mm (0.47 inch) Groove Weld (E) 10 mm (0.40 inch) Fillet Weld (F) Trunnion Casting (G) 10 mm (0.40 inch) Fillet Weld (H) Side-plate

• Remove any components that prevent access to the cracked weld

• Clean the weld of the oil, grease, and dirt

• Use the dye penetrant to inspect the entire area for possible cracks

• Protect machined surfaces from sparks and weld deposits

• Use an air carbon arc torch in order to remove cracks. Remove at least 50.8 mm (2.0 inch) of weld past the end of the crack

• When the crack is removed, make a V-shape groove for the weld repairs. The width of the groove should be at least two times the depth of the groove in order to ensure sufficient penetration

• Use the dye penetrant to inspect the gouged area in order to ensure that the crack has been removed

• Grind the area that was air arced to remove any slag and carbon pickup. Surface edges should be smooth and clean prior to welding

• Restore the casting to side-plate welds

• Apply a 10 mm (0.40 inch) fillet weld on casting-to-side-plate, and then a 12 mm (0.47 inch) groove weld to duplicate the production weld geometry as shown in Illustration 4

• Note the "NO WELD ZONE" in illustration 5, that extends 15 mm (0.60 inch) from the end of the notch in the casting to the start of the weld

• Order/sequence of welds is not specific. However, care must be given not to weld too much in one area at one time

• Caution should be taken in order to minimize distortion due to welding. Use of a brace or tie-bars between the frame and trunnions is recommended

• Weld passes should be blended smooth with the other weld beads

• Maintain a minimum of 120° C (250° F) interpass temperature

• Clean the weld (no slag) after each pass. Needle peen or hammer peen each pass

• Each weld pass should be free of crater cracks, slag inclusions, undercuts, porosity, and any other visible discontinuities

• All quality of the weld must conform to ANSI/AWS standard 14.3

• Next, add an additional 10 mm (0.40 inch) filet weld to the casting to groove weld from Point (A) to Point B as indicated in Illustration 5

• Lastly, grind both of the weld toes on the 10 mm (0.40 inch) weld (added in the previous bullet point) from Point (A) to Point (B)

• Grind the weld profile to a concave profile to blend into the casting with a 10 mm (0.40 inch) minimum toe radius as indicated in Illustration 5

Rear Trunnion Weld Post Treatment Requirements

Illustration 5	g03395061
Grind Weld Toe (A) Point A (B) Point B (J) 70 mm (2.75 inch) (K) "NO WELD ZONE" 15 mm (0.60 inch) from end of notch in casting

Illustration 6	g03395389
Rear Trunnion Example Add a 10 mm (0.40 inch) fillet weld per the length indicated

Illustration 7	g03395392
Rear Trunnion Example Add a 10 mm (0.40 inch) fillet weld per the length indicated

Illustration 8	g03395404
Example of blended toe radius

Illustration 9	g03395411
Example of blended toe radius

Illustration 10	g03395413
Example of blended toe radius Make sure to grind the weld toe all the way to the end of the weld to the frame side plate

Weld Toe Radius Inspection Requirements

Illustration 11	g03395062
(F) Trunnion Casting (L) 20 mm (0.79 inch) Diameter Circle

Add an additional 10 mm (0.40 inch) fillet weld to the casting groove weld from Point (A) to Point (B) as indicated.

Clean and inspect the weld. The weld must be free from cracks, porosity, undercut and incomplete fusion. All quality of the weld must conform to ANSI/AWS Standard 14.3

Next, grind the weld toes on the fillet weld added in the previous step from Point (A) to Point (B) .

Grind the weld toes to a concave profile that blends into the casting and frame to a 10 mm (0.40 inch) minimum toe radius.