Procedure to Repair the Front Suspension Casting on Certain 793 Off-Highway Trucks {7051, 7200} Caterpillar

Off-Highway Truck/Tractor

793 (S/N: 3SJ1-UP)

793B (S/N: 1HL1-UP)

793C (S/N: CBR1-UP; 4AR1-UP; ATY1-UP; 4GZ1-UP)

793D (S/N: FDB1-UP)

793F (S/N: SND1-UP; SSP1-UP; SXP1-UP; D3T1-UP; RBT1-UP)

Introduction

Reference: REHS1841 Special Instruction , "General Welding Procedures"

Reference: REHS7193 Special Instruction , "Procedure for the Inspection, Repair, and Component Replacement on the Frame of the 793F and the 793F Command For Hauling Off-Highway Trucks"

Reference: , REHS0541 Special Instruction , "Procedure for the Inspection, Repair, and Component Replacement on the Frames of Certain Off-Highway Trucks"

This Special Instruction contains the necessary instructions for repairing the front suspension casting on certain 793 Off-Highway Trucks.

Illustration 1	g06226047
View of the locations related to this procedure

The intent of this procedure is to provide a maximum life weld repair for through thickness cracks in specific locations identified on the front suspension support castings. To maximize life of the repair, access to inside the castings is imperative to address the root conditions of the repair.

The information in this Special Instruction will supplement already established casting repair procedures outlined in , REHS7193 Special Instruction , "Procedure for the Inspection, Repair, and Component Replacement on the Frame of the 793F and the 793F Command For Hauling Off-Highway Trucks".

For cracks that have not propagated through thickness or if there is not access to inside the casting refer to aforementioned casting repair procedure in , REHS7193 Special Instruction , "Procedure for the Inspection, Repair, and Component Replacement on the Frame of the 793F and the 793F Command For Hauling Off-Highway Trucks" and , REHS0541 Special Instruction , "Procedure for the Inspection, Repair, and Component Replacement on the Frames of Certain Off-Highway Trucks".

The cast steel material for 8X-3566 Support and 8X-3567 Support is a low carbon/manganese steel type that is readily weldable. The cast material for 464-1100 Support and 464-1101 Support is a low carbon/manganese/vanadium steel type that is also readily weldable.

Note: No preheat (above ambient temperature) is required for either material when welding in ideal conditions such as in a factory setting on new shot or sand blasted material. As a precaution a preheat/interpass will be required to offset field conditions and probable contamination absorption of the cracked casting.

Note: The simulated cracks in this procedure depict extreme cases where the cracks were not detected early to illustrate the full capacity of the repair process.

Do not perform any procedure in the Special Instruction until you have read the information and you understand the information.

Reference: Refer to machine appropriate Disassembly and Assembly for component removal.

Reference: , REHS1841 Special Instruction , "General Welding Procedures"

Important Safety Information

The following information is an explanation of various labels that are found in this document.

Warnings

The warning label informs the technician that an injury or death can occur as a result of a condition that may exist.

Notices

A notice informs the technician that component damage can occur as a result of a condition that exists.

Notes

A note contains general information for the technician about the operation that is being performed.

Proper repair is important to the safe operation and the reliable operation of this machine. This document outlines basic recommended procedures. Some of the procedures require special tools, devices, or work methods.

Before you perform any repairs or before you perform any maintenance, read all safety information. Understand all safety information before you perform any repairs or before you perform any maintenance.

Safety information is provided in this document and on the machine. If these hazard warnings are not heeded, bodily injury or death could occur to you or other persons.

The “Safety Alert Symbol” that is followed by a “Signal Word” identifies a hazard. “DANGER”, “WARNING”, and “CAUTION” are “Signal Words”.

Illustration 2	g00008666

The signal word “WARNING” has the following meanings:

• Pay Attention !

• Become Alert !

• Your Safety Is Involved !

The message that appears under the safety alert symbol explains the hazard.

Operations or conditions that may cause product damage are identified by "NOTICE" labels on the machine and in the service information.

The person that services the machine may be unfamiliar with many of the systems on the machine. Use caution when you perform service work. Special knowledge of the systems and of the components is important. Before you remove or disassemble any component, obtain knowledge of the system and knowledge of the component.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The safety information in this document and the safety information on the machine are not all inclusive. Determine that the tools, procedures, work methods, and operating techniques are safe. Determine that the operation, lubrication, maintenance, and repair procedures will not damage the machine. Determine that the operation, lubrication, maintenance, and repair procedures will not make the machine unsafe.

Basic Precautions

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Improper operation, lubrication, maintenance or repair of this product can be dangerous and could result in injury or death. Do not operate or perform any lubrication, maintenance or repair on this product, until you have read and understood the operation, lubrication, maintenance and repair information.

Always observe the list of basic precautions that follows:

Safety Signs

Safety signs include the items that follow: signs, information plates, and decals. Read all “Safety” signs on the machine before operating, lubricating, or repairing the machine. Understand all “Safety” signs on the machine before operating, lubricating, or repairing the machine. Replace any safety signs that are in the conditions that follow: damage, unreadable and missing.

Protective Equipment

When you work around the machine, always wear protective equipment that is required by the job conditions. Protective equipment includes the items that follow: hard hat, protective glasses, and protective shoes. In particular, wear protective glasses when you use a hammer or when you use a sledge hammer. When you weld, use the appropriate protective equipment that is required by the job conditions. Protective equipment for welding includes the items that follow: gloves, welding hood, goggles, and apron. Do not wear loose clothing or jewelry that can catch on parts of the machine.

Mounting and Dismounting

Use steps and handholds when you mount a machine. Also, use steps and handholds when you dismount a machine. Before you mount the machine, clean any mud or debris from steps, walkways, or work platforms. Always face the machine when you use steps, handholds, and walkways. When you cannot use the accesses on the machine, use ladders, scaffolds, or work platforms to perform safe repair operations.

Specifications for Cables, Chains, and Lifting Devices

Use approved cables, chains, and lifting devices to lift components. Refer to the manufacturer's weights to determine the application when you select the following items: cable, chain, and lifting devices. When you lift a component, the lift angle is critical. Refer to the Illustration that follows to see the effect of the lift angle on the working load limit.

Note: The lifting devices that are shown in this publication are not Caterpillar parts.

Note: Ensure that the hooks are equipped with a safety latch. Do not place a side load on the lifting eyes during a lifting operation.

Illustration 3	g00629745
Lift angles for lifting slings. (A) The load capacity is 100% of the working load limit for the sling. (B) The load capacity is 86% of the working load limit for the sling. (C) The load capacity is 70% of the working load limit for the sling. (D) The load capacity is 50% of the working load limit for the sling.

Hot Fluids and Parts

To avoid burns, be alert for hot parts on machines which have been stopped and hot fluids in lines, tubes and compartments.

Be careful when you remove filler caps, breathers, and plugs on the machine. Hold a rag over the cap or plug to prevent being sprayed by pressurized liquids. When the machine has been stopped, the danger of hot fluids is greater.

Corrosion Inhibitor

Corrosion inhibitor contains alkali. Avoid contact with the eyes. Do not allow corrosion inhibitor to contact the skin for extended periods of time. Avoid repeated contact with the skin. Do not drink corrosion inhibitor. If there is contact, immediately wash skin with soap and water. For contact with the eyes, flush the eyes with large amounts of water for at least 15 minutes. Seek medical attention.

Batteries

Do not smoke when an inspection of the battery electrolyte level is made. Never disconnect any charging unit circuit or battery circuit cable from the battery when the charging unit is operating. A spark can cause an explosion from the flammable vapor mixture of hydrogen and oxygen that is released from the electrolyte through the battery outlets. Do not allow battery electrolyte to contact skin or eyes. Battery electrolyte is an acid. If there is contact with battery electrolyte, immediately wash the skin with soap and water. For contact with the eyes, flush the eyes with large amounts of water for at least 15 minutes. Seek medical attention.

Pressurized Items

1. Always use a board or a piece of cardboard when you check for a leak. Leaking fluid under pressure can penetrate body tissue. Fluid penetration can cause serious injury and possible death. A pin hole leak can cause severe injury. If fluid is injected into your skin, you must get treatment immediately. Seek treatment from a doctor that is familiar with this type of injury.

2. Relieve all pressure in air, oil, or water systems before any lines, fittings, or related items are disconnected or removed. Always make sure that all raised components are blocked correctly. Be alert for possible pressure when you disconnect any device from a system that utilizes pressure.

3. Fuel lines that are damaged and fuel lines that are loose can cause fires. Lubrication lines that are damaged and lubrication lines that are loose can cause fires. Hydraulic lines, tubes, and hoses that are damaged can cause fires. Loose hydraulic lines, loose tubes, and loose hoses can cause fires. Do not bend or strike high-pressure lines. Do not install lines which have been bent or damaged. Check lines, tubes, and hoses carefully. Do not use your bare hand to check for leaks. If fluids are injected into your skin, you must get treatment immediately. Seek treatment from a doctor that is familiar with this type of injury.

4. Pressurized air or water can cause personal injury. When pressurized air or water is used for cleaning, wear a protective face shield, protective clothing, and protective shoes. The maximum air pressure for cleaning purposes must be below 205 kPa (30 psi). When you use a pressure washer, keep in mind that the nozzle pressures are high. The nozzle pressures are frequently above 13790 kPa (2000 psi). Follow all the recommended practices that are provided by the manufacturer of the pressure washer.

Approved Inspection Methods

Visual inspection (VT), magnetic particle inspection (MT), and ultrasonic inspection (UT) are required for certain procedures in this Special Instruction. Each of these inspection methods should be conducted and reported by qualified personnel. Do not use the magnetic particle inspection process around components that will be affected by magnetism.

Inspector Qualifications

Personnel who perform VT should be qualified and certified. Individuals should be certified for visual inspections at a minimum of American Welding Society Certified Welding Inspector (AWS CWI) or international equivalent.

Personnel who perform MT, and UT- ASNT (American Society of Nondestructive Testing) Level II (minimum) for each method used or international equivalent.

Welding Specifications and Qualifications

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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 kill. Read and understand the manufacturer's instruction and your employer's safety practices. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing zone and the general area. Wear correct eye, ear and body protection. Do not touch live electric parts. Refer to the American National Standard Z49.1, "Safety in Welding and Cutting" published by the American Welding Society, 2501 N.W. 7th Street, Miami, Florida 33125: OSHA Safety and Health Standards, 29 CFR 1910, available from U.S. Dept. of Labor, Washington D.C. 20210.

Note: Personal breathing protection should be worn by the personnel that are welding. Personal breathing protection will prevent fumes from entering the lungs of the person that is welding. Use a 237-5181 Respirator for breathing protection.

Qualifications

Welders must be qualified for the appropriate type of weld that is being performed. Welders must be qualified for the appropriate position of weld that is being performed. Welders must be qualified for the welding process that is being utilized, Flux Cored Arc Welding (FCAW). Refer to Specification ANSI/AWS D1.1 for information that regards qualification requirements. The welders must have used the process at some time within the last 6 months. The welders must complete the process of certification if the welders have not used the welding processes for 6 months.

Proper Welding Procedure on Machines and Engines with Electronic Controls

Proper precautions are necessary to prevent damage to electronic controls. When you weld on a machine with electronic controls, use the steps that follow:

1. Turn off the engine. Put the key start switch in the OFF position.

2. If the machine has a battery disconnect switch, open the switch. If the machine does not have a battery disconnect switch, disconnect the negative battery cable at the battery.

3. Attach the clamp for the ground cable as close as possible to the area that is being welded. This process will reduce the likelihood of damage from the welding current to the following components: bearings, hydraulic components, and electrical components. DO NOT weld plates to the frame for grounding/clamping purposes. Use existing blocks, brackets, bosses, and so on, to attach the clamp.

   Note: Do NOT use electrical components as a ground point for the welder. Do NOT use ground points for electronic components as a ground point for the welder.

4. Protect the wiring harnesses and machine surfaces from sparks and welding spatter.

Area Preparation

The area to be welded shall be clean, dry, and free of the following contaminants:

• Oil

• Grease

• Paint

• Dirt

• Rust

• Any fluids or moisture

All welding shall be conducted on base material heated and maintained at a minimum temperature of 15.6° C (60° F).

Note: Heating instructions (preheat, interpass, and postheat) for any specific repair shall override the minimum 15.6° C (60° F) requirement.

Note: Heat distortion of the base metal is possible when you weld. Avoid excessive heating of the base metal.

Welding Electrodes and Parameters

Flux Cored Welding Electrode for the FCAW Process

Use the Flux Cored Arc Welding (FCAW) with E71T-1 H8 (ANSI/A5.20) welding electrode and the manufacturer's shielding gases that are specified (typically 75% argon and 25% carbon dioxide). The H8 implies that the electrode is designed to provide less than 8 ml/100 g of diffusible hydrogen in the weld deposit. The weld that is deposited by the flux cored welding electrode will have the following minimum mechanical properties:

The table that follows show the recommended parameter range for out of position welding in the field for flux cored welding electrode diameter.

Note: The settings listed above are recommendations-based on experience from welding in the horizontal, vertical-up, and overhead positions. Slight changes in the voltage and amperage may be necessary due to welding position and various formulations by different electrode manufacturers. The use of higher parameters than specified for welding in the flat position is acceptable.

Use a polarity setting of DC reverse polarity. Remove the slag after each welding pass. The fast freezing characteristics of flux cored welding electrode increases the possibility of evolving gas that is trapped in the weld. Control the size of the weld to reduce the possibility of evolving gas that is trapped in the weld. The maximum size weld per pass shall be equivalent to that of a 8.0 mm (.32 inch) fillet weld.

Weld Inspection and Acceptance Criteria

General Weld Repair

Note: The simulated cracks in this procedure depict extreme cases where the cracks were not detected early to illustrate the full capacity of the repair process.

1. Ensure that the base material is at a minimum temperature of 125° C (257° F) preheat/inter-pass is required for any welding on the locations identified in this procedure. Maximum inter-pass temperature is 300° C (572° F).

   Note: When preheating by flame, the heat source should be removed for at least 1 min/inch of thickness and the temperature should be measured 75 mm (3.00 inch) from the center of the weld joint.

2. Protect machined surfaces from sparks and weld debris.

3. Weld starts/stops within a multi-pass weld shall be staggered and ground.

4. Inspection methods:

   • VT (Visual Testing)

   • MT (Magnetic Particle Testing)

   • UT (Ultrasonic Testing)

   Note: UT testing is not required for any of the crack locations where there are curved surfaces or planes at angles due to the complexity of interpretation.

5. Repair the prepared groove utilizing the recommendations provided in the "Welding Electrodes and Parameters" Section in this Special Instruction.

   • Remove the slag after each weld pass

   • All vertical welding shall be vertical up progression

   • Stagger weld starts and stops when completing multi-pass fillet welds and groove welds

6. Clean the weld area. Inspect the area that was welded. All weld quality shall conform to the criteria specified in the "Weld Inspection and Acceptance Criteria" section in this Special Instruction.

Component Removal

For this procedure removal of the front suspension cylinder is required. Removal of additional components beyond the front suspension cylinder may be required to have adequate access to perform the weld repairs. The person performing the repair should determine and provide a complete list of components that require removal to make the repairs.

Refer to machine appropriate Disassembly and Assembly for component removal.

Repair Procedure

Specific Casting Locations

Illustration 4	g06226050
View of location 1 and location 4

Illustration 5	g06226055
View of location 2 and location 3

Illustration 6	g06226058
View of location 5

• Location 1 - Front Bottom Outside Corner (FBOC)

• Location 2 - Rear Bottom Outside Corner (RBOC)

• Location 3 - Rear Bottom Inside Corner (RBIC)

• Location 4 - Front Top Outside Corner (FTOC)

• Location 5 - Parting Line Inside Apex (PLIA)

Note: This repair procedure covers through thickness cracks where access is available from both sides. The inside surface of the casting is not accessible in Locations 2 and 3. Due to this reality it is critical that cracks in these locations are repaired prior to going through thickness.

Repair of Location 1

Illustration 7	g06226063
View of typical cracking in Location 1

Illustration 8	g06226072

Note: Cracks in Location 1 typically grow in two primary directions (vertically up and horizontally towards the front rail). Refer to Illustration 8.

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Illustration 9	g06226094
View of FSSC opening dimensions (RH FSSC) (AA) 590 mm (23.0 inch) (BB) 235 mm (9.25 inch)

1. To maximize the life of the weld repair, it is imperative that both sides of the weld (root and cap) are accessible for placement of ceramics, inspection, and grinding/welding. Access is limited for Location 1 (if the suspension housing is removed) via the opening in the flange. Refer to Illustration 9.

   Note: The accessibility or reach criteria has been derived using an individual with a height of (5'11" and a weight of 195 lbs). A tall/thin individual may have better reach and a short/stocky person may have less reach. The dimensions given are an approximation.

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   Illustration 10	g06226116
   View of Location 1 - cast-in brackets (RH FSSC)

2. Cracks in the vertical direction are accessible from both sides for a given distance. The main obstacle is if the crack extends over toward the flange where there are cast-in brackets. Illustration 10 is an inside view of the FSSC (RH) showing the location of the cast-in brackets nearest the area.

   Note: The cast-in brackets are not structural design features, the cast-in brackets exist to support the casting through the solidification process.

   Note: Most of the observed cracks in Location 1 do not appear to extend too far into the cast-in bracket area, but rather appear to be on the edges.

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   Illustration 11	g06226162
   View of Location 1, no internal access area (RH FSSC) (CC) 200 mm (7.90 inch)

3. Cracks in the horizontal direction are only accessible from both sides for a minimal distance forward. Illustration 11 depicts the area that is not accessible from inside the casting.
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   Illustration 12	g06226171
   View of the reach limitations at Location 1 (DD) 300 mm (12.0 inch) Limits of accessibility

4. Illustration 12 depicts the reach limitations in the lower area from an internal perspective. The view shows the front half of the casting towards the front of the machine.
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   Illustration 13	g06226405
   View of Location 1 simulated crack (RH FSSC)

5. Simulated repairs were conducted on a new RH FSSC to determine the best method of repair for maximum life. The simulated repair for Location 1 is shown in Illustration 13.

   Note: Red permanent marker over white contrast paint.

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   Illustration 14	g06226439
   View of Location 1 wall thickness values (RH FSSC)

6. Before excavating the crack, measure the wall thickness in 25 mm (1.0 inch) increments on either side of the crack. Knowing the thickness will help in the excavation process to minimize the root opening for the subsequent weld repair. Illustration 14 depicts the wall thickness surrounding the crack.

   Note: The N/A indicates that there is a cast-in bracket directly beneath the UT probe/transducer that is giving an unrealistic value.

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   Illustration 15	g06226454
   View of crack excavation starting approximately 20 mm (0.80 inch) to 25 mm (1.0 inch) in front of the crack

   Note: Preparation of the weld joint should be done with care. The success or failure of the root pass(es) will depend on adherence to the root opening and root face dimensions.

7. To prevent the crack from propagating further, excavate each end of the crack. Start at a distance approximately 20 mm (0.80 inch) to 25 mm (1.0 inch) in front of the crack and excavate down and toward the crack. Refer to Illustration 15.
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   Illustration 16	g06226466
   View of excavating ends of crack while monitoring depth

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   Illustration 17	g06226468
   View of 76 mm (3 inch) OD and 3.2 mm (0.13 inch) cut-off wheel used to cut through the final depth of 4 mm (0.16 inch)

8. Continue excavating the crack and monitoring the depth using a scale. Excavate within 4 mm (0.16 inch) of the depth, then use a cutoff wheel to remove the final depth of the crack. Refer to Illustration 16 and Illustration 17.
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   Illustration 18	g06226477
   View of crack excavated to within 4 mm (0.16 inch) of depth (A) Air Carbon Arc gouging profile (B) Crack (EE) Section thickness (FF) 4 mm (0.16 inch)

   Note: A reciprocating saw can be used for curved areas where cut off wheel does not fit.

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   Illustration 19	g06226494
   View of crack excavated to within 4 mm (0.16 inch) of depth (C) 76 mm (3 inch) OD and 3.2 mm (0.13 inch) Cut-off wheel (EE) Section thickness (FF) 4 mm (0.16 inch) (GG) 4 mm (0.16 inch) Root opening

   Note: Using cut-off wheel (C) will likely result in approximately a 4 mm (0.16 inch) root opening (GG). A slightly thinner cutoff wheel to achieve a 3 mm (0.12 1 inch) root opening is perfectly acceptable. The crack size and orientation will drive which thickness of cutoff wheel is appropriate.

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   Illustration 20	g06226518
   View of crack excavated to within 4 mm (0.16 inch) of depth (D) Finish grind/sand to achieve 60 degree minimum included angle (EE) Section thickness (GG) 4 mm (0.16 inch) Root opening (HH) 2 mm (0.08 inch) Root face

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   Illustration 21	g06226739
   View of final dimensions (EE) Section thickness (GG) 4 mm (0.16 inch) Root opening (HH) 2 mm (0.08 inch) Root face (JJ) 60 degree minimum (KK) 30 degree

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   Illustration 22	g06226830
   View of final dimensions (lengthwise) (EE) Section thickness (HH) 2 mm (0.08 inch) Root face (LL) 45 degree

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   Illustration 23	g06226840
   View of Location 1 prepared (externally)

9. Once each end of the crack has been found and ground out, proceed to preparing the rest of the crack length for repair. Refer to Illustration 18 through Illustration 23.

   Note: Perform MT checks throughout the excavation and preparation stages to identify and remove all cracks.

10. Perform final MT to ensure that the entirety of the crack has been removed.
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    NOTICE
    Special care should be taken when removing the cast-in brackets. The cast-in brackets should be ground/sanded to the profile of the casting such that no stress risers are present.

11. Grind/sand the root side of the preparation to allow proper usage of the ceramics with backing tape. In addition, cast-in brackets that interfere with the application of the ceramics may require removal.

    Note: For this repair only a few cast-in brackets needed to be removed.

12. Apply ceramic backing ensuring that the ceramic backing is centered and tight to the surface.

    Note: Successful use of any ceramics requires that all gaps are minimized as much as possible.

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    Illustration 24	g06226847
    View of common ceramics used

13. The ceramic shape utilized will depend on the inside profile of the casting and the nature of the direction of the crack.

    Illustration 24 depicts the ceramic (without tape) and the corresponding back bead profile. The concave profile of the ceramic will produce a back bead profile that looks like a weld profile.

    This ceramic shape is good for small root openings ( 3 mm (0.12 inch) to 4 mm (0.16 inch)), a fairly straight preparation, and a flat surface on the inside surface of the casting.

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    Illustration 25	g06226856
    View of non-linear segmented ceramics

14. If the preparation (crack) is other than straight, then a ceramic that is segmented to accommodate a non-linear direction is recommended. Refer to Illustration 25 for an example of a segmented non-linear ceramic.
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    Illustration 26	g06226891
    View of high temperature tape

15. The segmented ceramics are typically held together either by a rubber band or metal wire. This particular ceramic has a concave profile that will result in a convex back bead profile.

    Ceramics typically do not come attached to a backing tape so adjustments can be made for the desired shape.

    A roll of high temperature tape will be needed to hold the ceramics in place. Refer to Illustration 26.

    Note: The roll of high temperature tape is approximately 100 mm (4.0 inch) wide by 150 m (500 ft) long. The tape usually comes in various widths and lengths.

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    Illustration 27	g06226915
    View of segmented ceramic shapes for curved surfaces

16. Another ceramic shape that should be considered is shown in Illustration 27. This ceramic is useful when the inside surface of the casting profile is other than flat.
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    Illustration 28	g06226918

17. Once the appropriate ceramics are selected, the ceramic should be centered and taped on the preparation. The image on the left side of Illustration 28 depicts the ceramics and tape in place on the root side. The image on the right side of Illustration 28 depicts the ceramics in place (top side view).

    Note: An extra layer of high temperature tape was utilized and is recommended to allow ceramics to stay in position.

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    Illustration 29	g06227074
    View of horizontal two-pass root weld (back bead profile) (E) Second pass (F) First pass

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    Illustration 30	g06227083
    View of horizontal one-pass root (back bead profile)

18. The root opening for this weld joint was 5 mm (0.20 inch) to 6 mm (0.24 inch) along the length and also resulted in welding from the horizontal position transitioning into the vertical up position. Vertical position welding can accommodate a single root pass for larger root openings when using ceramics, however the limit for welding in a single pass in the horizontal position is a root opening of 3 mm (0.12 inch) to 4 mm (0.16 inch). Once the root opening increases beyond 4 mm (0.16 inch), gravity negatively affects fusion and filling of the top side of the joint. Two-pass root works best for this particular root opening in the horizontal position. Illustration 29 depicts the back bead profile of a two-pass horizontal weld on the FSSC. Illustration 30 shows the back bead profile of a one-pass horizontal weld on plate, where the root opening is less than 4 mm (0.16 inch).

    Note: Additional information related to how to handle large root openings in Section "What if There is a Large Root Opening" in Section "Repair of Location 5 (Not Situated at the Apex or Angled Planes)".

19. Pre-heat to 125° C (250° F). Do not focus the gas torch directly on the weld joint and ceramics. The pressure and heat tend to move the ceramics and weaken the tape adhesion.
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    Illustration 31	g06227101
    View of Location 1 first root pass (H) Fist root pass

20. Weld first root pass. Grinding of the first pass was required prior to placing the second root pass. The goal is to achieve a 2 mm (0.08 inch) to 3 mm (0.12 inch) root opening between the first root pass and the preparation.
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    Illustration 32	g06227109
    View of Location 1 second root pass (J) Second root pass

21. Weld second root pass. Parameters used in the root:

    • WFS = 300 ipm

    • Volt = 24.5

    • Amp ~ 180–200

    Note: If the root opening would have been 3 mm (0.12 inch) to 4 mm (0.16 inch), the root could have been completed in one pass. Since the root opening was slightly larger, the root had to be done in two passes.

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    Illustration 33	g06227112
    View of first layer ground prior to second layer

22. If the profile of the root pass(es) is convex, dress the face of the weld using the cutoff wheel for the first one or two weld layers. An example is shown in Illustration 33 where the first layer (comprised of two passes) has been ground using the 1/8 inch cut-off wheel.

    Note: If you feel that you are unable to penetrate through the ceramics on either or both passes, remove the ceramic to inspect the back bead profile. If issues exist, then grind or cut out the root passes and repeat. Otherwise, apply second layer of weld before removing ceramic backing.

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    Illustration 34	g06227121
    View of ceramics removed

23. Once the second layer of weld has been applied, remove the ceramic backing and inspect the root side of the welds.

    Illustration 34 shows the root side of the weld with the ceramics removed. Notice the extent of the grinding/sanding required on the cast-in brackets.

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    Illustration 35	g06227125
    Close-up view of root

24. Illustration 35 is a closer view showing the two passes that make up the root of the weld.

    Note: The back bead profile shown is a result of modifying the standard ceramic shape shown in Illustration 24. At the time of welding segmented ceramics were not available. However, the back bead profile does not necessarily matter since it will be sanded off. Sidewall fusion at the root is the primary goal.

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    Illustration 36	g06227147
    View of the root side of the repair after sanding

25. Sand the root side using the curved PFERD flap sanding disc. Illustration 36 depicts the root side after sanding.
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    Illustration 37	g06227154
    View of pneumatic peening device

26. Continue welding the fill passes until complete. Use standard needle peening (bundle) shown in Illustration 37, to remove the slag and treat the surface on each weld pass. Parameter used for the fill passes:

    • WFS = 350 ipm

    • Volt = 26

    • Amp ~200–240

    Note: Do not peen the root pass(es) or the cover passes until after sanding and MT verification.

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    Illustration 38	g06227181
    View of Location 1 welding complete

27. Illustration 38 shows the welding completed. Run on/run off (weld tabs) were added for the last layer. Previous layers have the weld starts and stops dressed/feathered with a tungsten carbide bur bit.
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    Illustration 39	g06227187
    View of Location 1 sanding complete

28. After welding is complete, remove weld tabs and sand excess weld metal and weld tabs flush with the surrounding profile. Refer to Illustration 39. Sanding was completed using 36 grit flexible sanding discs and the curved PFERD flap sanding discs.

29. MT the surface to ensure compliance to acceptance criteria.
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    Illustration 40	g06227192
    View of needle peening completed

30. Needle peen both surfaces (inside and outside). Illustration 40 depicts the peening coverage on the outside surface.

Key Concepts for Welding Location 1

• A root opening of 3 mm (0.12 inch) to 4 mm (0.16 inch) is ideal for FCAW the root pass with ceramics.

• For large root openings greater than 4 mm (0.16 inch) refer to Section "What if There is a Large Root Opening".

• Preparation of the weld joint is critical. Do not take short cuts.

• Removal of the cast-in brackets is required to achieve a good root pass that can be dressed flush by grinding/sanding.

• Choosing the right ceramics is critical and having several to types to choose from is key. The ceramics need to be a good, tight fit.

• Use at least an extra layer of high temperature tape to secure the ceramics in place.

Repair of Location 5

Illustration 41	g06227208
View of Location 5 crack examples (RH and LH )

Illustration 42	g06227219
View of Location 5 crack growth directions (RH FSSC)

The cracks in Location 5 typically grow in two primary directions (vertically and horizontally) sometimes crossing at the apex as shown in Illustration 42.

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Illustration 43	g06227225
View of Location 5 inside reach limitations (RH FSSC) (AA) 500 mm (20.0 inch) (BB) 200 mm (8.0 inch) (CC) 400 mm (15.75 inch)

1. To maximize the life of the weld repair, it is imperative that both sides of the weld (root and cap) are accessible for placement of ceramics, inspection, and grinding/welding. "Some" access is possible for Location 5 (if the suspension housing is removed) via the opening in the flange.

   Note: The accessibility or reach criteria has been derived using an individual with a height of (5'11" and a weight of 195 lbs). A tall/thin individual may have better reach and a short/stocky person may have less reach. The dimensions given are an approximation.

   Illustration 43 indicates the "average reach" for grinding/sanding, welding, and applying ceramics effectively to the inside surface of the casting.

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   Illustration 44	g06227233
   View of Location 5 cast-in brackets (RH)

2. Cracks from the apex back toward the flange (and opening) have the best accessibility in terms of reach, however there are cast-in brackets present. Illustration 44 is an inside view of the FSSC (RH) showing the cast-in brackets location for the top area.

   Note: The cast-in brackets are not structural design features, the cast-in brackets exist to support the casting through the solidification process.

   Note: If the crack extends over into the area where there are cast-in brackets, the cast-in brackets will need to be removed, to ensure maximum life of the repair.

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   Illustration 45	g06227502
   View of Location 5 simulated crack (RH FSSC)

3. Simulated repairs were conducted on a new RH FSSC to determine the best method of repair for maximum life. The simulated repair for location 5 is shown in Illustration 45.

   Note: Red permanent marker over white contrast paint.

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   Illustration 46	g06227563
   View of Location 5 wall thickness values (RH FSSC)

4. Before starting excavation of the crack, measure the wall thickness in 25 mm (1.0 inch) increments on either side of the crack.

   Knowing the wall thickness will help in the excavation process to minimize the root opening for the subsequent weld repair. Illustration 46 depicts the wall thickness surrounding the crack.

   Note: The N/A indicates that there is a cast-in bracket directly beneath the UT probe/transducer that is giving an unrealistic value.

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   Illustration 47	g06227571
   View of crack excavation starting approximately 20 mm (0.80 inch) to 25 mm (1.0 inch) in front of the crack

5. To prevent the crack from propagating further, excavate each end of the crack. Start at a distance approximately 20 mm (0.80 inch) to 25 mm (1.0 inch) in front of the crack and excavate down and toward the crack. Refer to Illustration 47.
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   Illustration 48	g06227621
   View of excavating the ends of the crack while monitoring depth

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   Illustration 49	g06227629
   View of 76 mm (3 inch) OD and 3.2 mm (0.13 inch) cut-off wheel used to cut through the final depth of 4 mm (0.16 inch)

6. Continue excavating the crack and monitoring the depth using a scale. Excavate within 4 mm (0.16 inch) of the depth, then use a cutoff wheel to remove the final depth of the crack. Refer to Illustration 48 and Illustration 49.
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   Illustration 50	g06227642
   View of crack excavated to within 4 mm (0.16 inch) of depth (B) Air Carbon Arc gouging profile (C) Crack (DD) Section thickness (EE) 4 mm (0.16 inch)

   Note: A reciprocating saw can be used for curved areas where cut off wheel does not fit.

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   Illustration 51	g06227645
   View of crack excavated to within 4 mm (0.16 inch) of depth (D) 76 mm (3 inch) OD and 3.2 mm (0.13 inch) Cut-off wheel (DD) Section thickness (FF) 4 mm (0.16 inch) (EE) 4 mm (0.16 inch) Root opening

   Note: Using cut-off wheel (D) will likely result in approximately a 4 mm (0.16 inch) root opening (FF). A slightly thinner cutoff wheel to achieve a 3 mm (0.12 1 inch) root opening is perfectly acceptable. The crack size and orientation will drive which thickness of cutoff wheel is appropriate.

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   Illustration 52	g06227652
   View of crack excavated to within 4 mm (0.16 inch) of depth (E) Finish grind/sand to achieve 60 degree minimum included angle (DD) Section thickness (FF) 4 mm (0.16 inch) Root opening (GG) 2 mm (0.08 inch) Root face

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   Illustration 53	g06227690
   View of final dimensions (DD) Section thickness (FF) 4 mm (0.16 inch) Root opening (GG) 2 mm (0.08 inch) Root face (HH) 60 degree minimum (JJ) 30 degree

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   Illustration 54	g06227745
   View of final dimensions (lengthwise) (EE) Section thickness (HH) 2 mm (0.08 inch) Root face (LL) 45 degree

7. Once each end of the crack has been found and ground out, proceed to preparing the rest of the crack length for repair. Refer to Illustration 50 through Illustration 54.

   Note: Perform MT checks throughout the excavation and preparation stages to identify and remove all cracks.

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   Illustration 55	g06227751
   View of Location 5 preparation (externally)

8. Illustration 55 shows Location 5 prepared in two different ways.

   The image on the left has both the vertical and horizontal direction fully excavated and prepared. The image on the right has only the vertical direction fully excavated and prepared. Either way is fine and will likely be determined by crack length, direction, root opening, and possibly personal preference.

   Note: This procedure will show the progression for the scenario in which both the vertical and horizontal directions are fully excavated and prepared.

9. Perform a final MT to ensure that the entirety of the crack has been removed.
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   NOTICE
   Special care should be taken when removing the cast-in brackets. The cast-in brackets should be ground/sanded to the profile of the casting such that no stress risers are present.

10. Grind/sand the root side of the preparation to allow proper usage of the ceramics with backing tape. In addition, cast-in brackets that interfere with the application of the ceramics may require removal.

    Note: For this repair 5 to 6 cast-in brackets were removed.

    Note: No arc air gouging was done inside the casting. Only grinding/sanding was used to remove the cast-in brackets.

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    Illustration 56	g06227814
    View of Location 5 preparation (internally)

11. In Illustration 56 there are two internal weld repairs indicated by the arrows. These are repairs performed at the foundry. Dress these repairs flush by grinding/sanding.

    Note: If there are other weld repairs that cannot be dressed flush (due to reach), document with photos and forward to the Product Group via Dealer Service Network (DSN).

12. There are essentially two repairs to be made for this scenario. The decision to weld which first will depend on that particular situation. In this case the horizontal weld was performed first and the vertical weld second.

    Note: The root opening for this weld joint was intentionally made to be larger than 3 mm (0.12 inch) to 4 mm (0.16 inch) and varied throughout the length to simulate actual field conditions. The actual root opening was 4 mm (0.16 inch) to 6 mm (0.24 inch).

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    Illustration 57	g06227824
    View of Location 5 plane angles (internally) LH FSSC

13. This area of the casting has multiple planes that join at the apex. The angles are shown in Illustration 57.
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    Illustration 58	g06227829

14. Based on the angles in Illustration 57, two ceramics were developed and tried (112 degree and 134 degree). The ceramics are shown in Illustration 58.

    Note: The profile of the internal casting favored the use of the 134 degree ceramic for all four plane angles.

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    Illustration 59	g06227832
    View of Location 5 horizontal ceramic geometry

15. The 145 degree ceramic shown in Illustration 59 is a stocked item and can be used if modified slightly. The modification consists of grinding the point flat (or concave) to look similar to the custom ceramics.

16. The following Illustrations depict a couple of different approaches for selecting the appropriate ceramics.
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    Illustration 60	g06228160
    View of Location 5 ceramics in place (root side)

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    Illustration 61	g06228161
    View of Location 5 ceramics in place (top side)

17. The first example in Illustration 60 and Illustration 61 utilized the modified 145 degree ceramics.
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    Illustration 62	g06228182
    View of Location 5 ceramics (second example)

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    Illustration 63	g06228191
    View of Location 5 ceramics (second example) continued

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    Illustration 64	g06228197
    View of Location 5 ceramics (second example, top side)

18. The second example in Illustration 62 , Illustration 63, and Illustration 64 use multiple different ceramics in an attempt to obtain the best fit.

19. With the ceramics in place, the repair is ready to weld.

20. Pre-heat to 125° C (250° F). Do not focus the gas torch directly on the weld joint and ceramics. The pressure and heat tend to move the ceramics and weaken the tape adhesion.
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    Illustration 65	g06228230
    View of pie-shaped pieces in place

21. For fully excavated and prepared in both directions, weld in pie-shaped pieces on top and bottom as shown in Illustration 65, then weld the root pass(es).

    Parameters use in the root:

    • WFS = 300 ipm

    • Volt = 24.5

    • Amp ~ 180–200

    Note: If you feel that you are unable to penetrate through the ceramics on either or both passes, remove the ceramic to inspect the back bead profile. If issues exist, then grind or cut out the root passes and repeat. Otherwise, apply second layer of weld before removing ceramic backing.

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    Illustration 66	g06228268
    View after second weld layer

22. Illustration 66 shows that a second layer of weld was added, ground, and peened.
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    Illustration 67	g06228273
    View of the horizontal back bead profile

23. Once the second layer of weld has been applied, remove the ceramic backing and inspect the root side of the welds. Illustration 67 shows the views of the inside back bead profile.
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    Illustration 68	g06228278
    View of the horizontal welds dressed by sanding

24. Sand and inspect the root side prior to filling the rest of the weld joint. Illustration 68 depicts the root side after sanding.

    Note: The image is showing the horizontal back bead that has been sanded to profile.

25. After the root side has passed MT, re-establish preheat.

26. Continue welding the fill passes until complete.

    Parameters use in the root:

    • WFS = 350 ipm

    • Volt = 26

    • Amp ~ 200–240

    Note: Do not needle peen the root pass(es) or the cover passes until after sanding and MT verification.

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    Illustration 69	g06228309
    View of welding continued with weld tabs in place

27. Attach run on/run off tabs. Illustration 69 depicts welding in progress with the run on/run off tabs tacked in place.
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    Illustration 70	g06228316

28. Complete the welding. Illustration 70 shows the welding completed and ready for sanding to profile.
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    Illustration 71	g06228329
    View of sanding competed

29. After welding is complete, remove the weld tabs and sand excess weld metal and weld tabs flush with the surrounding profile. In addition, the pie shaped pieces and weld need to be removed for the vertical up welding. Refer to Illustration 71.

    Note: Sanding was completed using 36 grit flexible sanding discs.

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    Illustration 72	g06228337
    View of the wide root opening at the apex

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    Illustration 73	g06228610
    View of two segments of ceramics for large root opening and STT process

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    Illustration 74	g06228616
    View of the top side

30. The vertical weld can now be addressed. The apex has a wide root opening making it difficult to weld. In this case the apex area was first welded using standard ceramics and the STT process. Refer to Illustration 72.

    Note: The STT process is a specialized pulsed, short circuit process developed by Lincoln electric for open root welding. The STT process is detailed in REHS7193 for use in one-sided repairs.

    Note: The segmented ceramics used for curved profiles could also be used with FCAW.

    If, utilizing existing standard ceramics attach two segments. Due to the angularity some grinding of the ceramics is required to minimize the gap between segments. Refer to Illustration 72, Illustration 73, and Illustration 74.

31. Pre-heat to 125° C (250° F). Do not focus the gas torch directly on the weld joint and ceramics. The pressure and heat tend to move the ceramics and weaken the tape adhesion.

32. Weld root pass. Unlike traditional vertical up welding, the progression for STT is vertical down.

    Parameters use in the root:

    • Synergic Program: 329

    • Shielding Gas: 75/25 (Ar/CO₂

    • Electrode: ER70S-3 (0.045" dia)

    • WFS: 115 ipm

    • Trim: 1.0
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    Illustration 75	g06228664

33. The back bead and top profile for this segment are shown in Illustration 75. Use a cutoff disc to taper/feather the weld starts and stops prior to welding the other root passes to obtain good fusion at the tie-ins.

    Note: Regardless of welding process used, it is good practice to weld the root pass at the apex first as shown in Illustration 75.

    Note: In cases where the root opening (gap) conditions are not conducive to ceramics and the FCAW process, there are various processes that can be adapted. Miller has a competing process called RMD that is similar to STT. In addition, use of GTAW or even SMAW would be acceptable if the welders have sufficient skill and experience.

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    Illustration 76	g06228704
    View of the bottom segment root opening

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    Illustration 77	g06228716
    View of the ceramics in place

34. The bottom and top segments have root openings that vary from 3.5 mm (0.14 inch) to 5.5 mm (0.22 inch). Based on the varying root openings the standard ceramics and FCAW process will be satisfactory. Refer to Illustration 76 and Illustration 77.
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    Illustration 78	g06228746
    View of the resulting back bead profile

35. Weld the root pass. Illustration 78 shows the back bead profile.

    Note: If you feel that you are unable to penetrate through the ceramics on either or both passes, remove the ceramic to inspect the back bead profile. If issues exist, then grind or cut out the root passes and repeat. Otherwise, apply second layer of weld before removing ceramic backing.

    Parameters use in the root:

    • WFS = 300 ipm

    • Volt = 24.5

    • Amp ~ 180–200

36. Pre-heat to 125° C (250° F). Do not focus the gas torch directly on the weld joint and ceramics. The pressure and heat tend to move the ceramics and weaken the tape adhesion.
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    Illustration 79	g06228760
    View of the top segment root opening

37. The top segment root opening and fit up are shown in Illustration 79.
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    Illustration 80	g06228765
    View of the ceramics in place on the top segment

38. Standard ceramics were used (same as on the bottom segment). Refer to Illustration 80.
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    Illustration 81	g06228786
    View of the resulting back bead profile

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    Illustration 82	g06228788
    View of the entire length back bead profile

39. Weld the root pass. Illustration 81 shows the back bead profile, and the full length back bead profile is shown in Illustration 82.

    Note: If you feel that you are unable to penetrate through the ceramics on either or both passes, remove the ceramic to inspect the back bead profile. If issues exist, then grind or cut out the root passes and repeat. Otherwise, apply second layer of weld before removing ceramic backing.

    Parameters use in the root:

    • WFS = 300 ipm

    • Volt = 24.5

    • Amp ~ 180–200

40. Pre-heat to 125° C (250° F). Do not focus the gas torch directly on the weld joint and ceramics. The pressure and heat tend to move the ceramics and weaken the tape adhesion.
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    Illustration 83	g06228791
    View of second weld layer applied

41. Apply second weld layer.

    Note: The apex and angled planes require various grinding/sanding attachments. Refer to Appendix A.

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    Illustration 84	g06228794
    View of the back bead sanded flush to surrounding profile

42. Sand and inspect the root side prior to filling the rest of the weld joint. Illustration 84 depicts the root side after sanding.

43. After the root side has passed MT, re-establish preheat.

44. Continue welding the fill passes until complete. Use standard needle peening (bundle) to remove slag and treat the surfaces.

    Parameters use for the fill passes:

    • WFS = 350 ipm

    • Volt = 26

    • Amp ~ 200–240

    Note: Do not needle peen the root pass(es) or the cover passes until after sanding and MT verification.

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    Illustration 85	g06228804
    View of welding in progress

45. Illustration 85 depicts the welding in progress. Utilize one weld start/stop location to account for positioning (shown by arrow).
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    Illustration 86	g06228810
    View of welding completed

46. Finish welding complete. Attach run on/run off tabs for the last layer. Refer to Illustration 86.
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    Illustration 87	g06228845
    View of sanding completed

47. After welding is complete, remove weld tabs and sand excess weld material and weld tabs flush with the surrounding profile, refer to Illustration 87. Sanding was completed using 36 grit flexible sanding discs.
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    Illustration 88	g06228866
    View of the surfaces peened (inside and outside)

48. Needle peen the entire sanded surface (both inside and outside). The finished surfaces are shown in Illustration 88.

Key Concepts for Welding Location 5 (The Cross)

• A root opening of 3 mm (0.12 inch) to 4 mm (0.16 inch) is ideal for FCAW the root pass with ceramics.

• For large root openings greater than 4 mm (0.16 inch) refer to Section "What if There is a Large Root Opening".

• Preparation of the weld joint is critical. Do not take short cuts.

• Removal of the cast-in brackets is required to achieve a good root pass that can be dressed flush by grinding/sanding.

• The decision to excavate both cracks at the same time or each crack separately depends on the situation. Experience over time will be the driver.

• Choosing the right ceramics is critical and having several ceramics to choose from is key. The ceramics need to be a good, tight fit.

• There are no perfect ceramics for the apex.

• Use at least an extra layer of high temperature tape to secure the ceramics in place.

Repair of Location 5 (Not Situated at the Apex or Angled Planes)

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Illustration 89	g06228894
View of miscellaneous repairs (outside view)

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Illustration 90	g06228907

1. If repair is required within the reach area, but not in the specific area previously described, then the repair is relatively straightforward. Illustration 89 and Illustration 90 depict repairs made in the Location 5 area.

   Note: Repairs can be ultrasonically tested (UT) with relative confidence.

2. The vertically oriented preparation had a 3.5 mm (0.14 inch) to 4 mm (0.16 inch) root opening that is relatively consistent along the length.

   The two horizontally oriented preparations had different root openings. The top one had a 3.5 mm (0.14 inch) to 4 mm (0.16 inch) root opening and the bottom one had a larger 5 mm (0.20 inch) to 6 mm (0.24 inch) root opening.

   Standard ceramic backing and the same FCAW parameters as previously mentioned were used.

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   Illustration 91	g06228916
   View of vertical up back bead profile

3. The vertical back bead profile is shown in Illustration 91.

   Note: Welding vertically up with FCAW and ceramic backing is fairly easy as long as the ceramic is tight against the material, the root opening is not excessive, and there is sufficient tape (two layers) supporting the ceramics.

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   Illustration 92	g06228917
   View of a cross section of the repair

4. The cross section (after sanding flush on both sides) is shown in Illustration 92.
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   Illustration 93	g06229183
   View of horizontal back bead profile (after minor repair)

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   Illustration 94	g06229190
   View of end ramps too tight

5. The back bead of a single pass horizontal repair is shown in Illustration 93. The root opening was 3.5 mm (0.14 inch). Welding was relatively easy, however the "ramp" (entrance/exit) into and out of the preparation was too narrow, refer to Illustration 94. As a result, there was a minor lack of penetration at the ends. Each of the ends were opened up using a tungsten carbide bur bit and then welded from the inside, refer to 93.

   Note: Ensure that the ends of the preparation are opened up when welding in the horizontal position.

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   Illustration 95	g06229204
   View of horizontal two-pass root weld back bead

6. The back bead of a two-pass horizontal repair is shown in Illustration 95. The root opening was 5 mm (0.20 inch) to 6 mm (0.24 inch). Welding the root will require two passes, but it is not difficult.

   Note: The main thing to remember is that if the first root pass reduces the root opening to less than 2 mm (0.08 inch) then the root opening will have to be opened up using a grinder or cutoff wheel to penetrate through to the ceramic backing on the second root pass.

What if There is a Large Root Opening

1. For vertical welds, root openings of 8 mm (0.31 inch), 12 mm (0.47 inch), and 16 mm (0.63 inch) were tested. Tests were performed on plate and then on the casting.
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   Illustration 96	g06229240
   View of 8 mm (0.31 inch) root opening

2. For root opening of 8 mm (0.31 inch) using the standard concave ceramic profile tested successful. The resulting weld is shown in Illustration 96.
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   Illustration 97	g06229260
   View of 16 mm (0.63 inch) root opening

3. For root openings of 12 mm (0.47 inch) and 16 mm (0.63 inch) flat surface (not concave) ceramics were used. Using ceramics with concave profiles resulted in a weld with too much molten weld material that was too difficult to manage.

   The 16 mm (0.63 inch) test weld is shown in Illustration 97. The back bead profile is on the right side of the Illustration.

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   Illustration 98	g06229282
   View of 13 mm (0.51 inch) to 20 mm (0.80 0 inch) root opening

4. A couple of prepared weld joints were welded on the casting with large root openings. Illustration 98 varied from 13 mm (0.51 inch) to 20 mm (0.80 0 inch) for the root opening. The weld joint was welded for 150 mm (6.0 inch) and the arc was extinguished to determine the viability of restarting the arc without defects.
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   Illustration 99	g06229300
   View of center line crack at weld stop

5. After removing the slag, a center line crack was revealed. Refer to Illustration 99.

   Typically center line cracking is a result of a deep, narrow weld shape, or a wide, shallow weld shape. This weld is definitely a wide, shallow shape. The center line cracking was not noticed during the welding of the test plates, because the arc was not typically stopped prior to the end.

   Further testing revealed that root openings equal to or less than 8 mm (0.31 inch) did not result in center line cracking.

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   Illustration 100	g06229307
   View of non-linear segmented ceramics

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   Illustration 101	g06229308
   View of U shaped ceramics

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   Illustration 102	g06229312
   View of standard concave ceramics

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   Illustration 103	g06229314
   View of segmented ceramics shapes for curved surfaces

6. As a result, 8 mm (0.31 inch) is the maximum root opening for ceramic backing use in the vertical direction. Illustration 100 through Illustration 103 show some ceramic backing profiles that worked well for root openings equal to or less than 8 mm (0.31 inch) in the vertical up position.
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   Illustration 104	g06229318
   View of a large root opening

7. For root openings greater than 8 mm (0.31 inch) it was decided to implement steel backing to ensure a quality root pass(es). Illustration 104 is a vertical weld preparation with a root opening of approximately 15 mm (0.60 inch).

8. For this scenario a 6 mm (0.24 inch) thick backing strip by 38 mm (1.50 inch) wide by the length of the opening plus 12 mm (0.47 inch) minimum. This backing will provide overlap on the sides and at the ends to prevent burning through.

   Note: The backing strip minimum size requirements are that the backing strip should be 12 mm (0.47 inch) wider than the root opening (to provide 6 mm (0.24 inch) overlap on each side), 12 mm (0.47 inch) longer than the prepared length (to provide a 6 mm (0.24 inch) overlap at each end), and thick enough to prevent burning through. A 6 mm (0.24 inch) thickness works fine, but a 4 mm (0.16 inch) could be used to minimize grinding/sanding time.

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   Illustration 105	g06229323
   View of marking and inserting the steel backing

9. Illustration 105 shows marking the appropriate length to cut and then the steel backing in place.
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   Illustration 106	g06229325
   View of tacking and welding the root passes

10. Apply preheat. Tack the steel backing in place, sand (feather) tack welds and then weld the root passes. Refer to Illustration 106.
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    Illustration 107	g06229326
    View of finish welding and sanded flush

11. Weld complete and then sand off excess weld metal on the outside surface. Refer to Illustration 107.
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    Illustration 108	g06229327
    View of the inside surface sanded flush

12. Internally grind/sand of the steel backing strip.

    Note: It took approximately 15 minutes to grind off the steel backing strip shown in Illustration 108. The steel backing strip was approximately 150 mm (6.0 inch) long by 38 mm (1.50 inch) wide and 6 mm (0.24 inch) thick.

1. Horizontal welding can accommodate larger root openings than vertical welding, however single pass welding in horizontal position is typically limited to less than 4 mm (0.16 inch) root opening.

   After 4 mm (0.16 inch) the weld starts to get too large to achieve proper fusion of the top weld toe, and the weld will generally result in underfill or undercut on the back bead. This weld is the same as when welding multi-pass root passes. The final or top root opening must be reduced to 2 mm (0.08 inch) to 3 mm (0.11 inch) to result in a good back bead profile.

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   Illustration 109	g06229329
   View of the prepared weld

2. Illustration 109 shows the weld preparation with a root opening of approximately 10 mm (0.40 inch).
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   Illustration 110	g06229330
   View of the first pass completed and the ends ground

3. Weld the first pass and grind the ends. Refer to Illustration 110
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   Illustration 111	g06229331
   View of second pass complete

4. Weld the second root pass complete and grind the ends. The remaining root opening is approximately 4 mm (0.16 inch) plus. Refer to Illustration 111.
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   Illustration 112	g06229332
   View of the third and final pass complete

5. Weld the third and final pass complete. Refer to Illustration 112.
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   Illustration 113	g06229592
   View of the back bead profile

6. Illustration 113 shows the resulting back bead(s) profile.
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   Illustration 114	g06229597
   View of the repair completed

7. A weld repair was made internally to the casting before sanding flush. Refer to Illustration 114.
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   Illustration 115	g06229617
   View of ceramics

8. In addition, the selection of ceramics is important in achieving the correct back bead profile. Flat ceramics do not allow enough weld metal to protrude through to the back side when welding in the horizontal position resulting in underfill. Therefore, ceramics with some recess or concavity are the best choice. Illustration 115 shows two profiles that work well.

   Note: There is also the option to use steel backing and then grind/sand the steel backing flush.

Key Concepts for Welding Large Root Openings

• Vertical - use steel backing for root openings larger than 8 mm (0.31 inch).

• Horizontal - do not use flat backing ceramics as the flat backing ceramics can result in underfill or undercut.

• Horizontal - stack welds until the top root opening is 2 mm (0.08 inch) to 3 mm (0.12 inch).

• Vertical/Horizontal - minor repair welding to the root or back bead side is possible.

Reasons for Recommending Steel Backing

• Seldom did a repair using ceramic backing result in a back bead profile that did not require some minor additions of weld metal internally.

• Steel backing strips usually guarantee consistent quality root passes that do not require any further addition of weld metal.

• Welding of the root passes for the larger root opening is easier than with ceramic backing.

• Removal of the steel backing by grinding/sanding does not take any longer than removal of the back bead excess weld metal.

Repair of Location 2

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Illustration 116	g06229644
View of Location 2

1. Access to the root or inside is not possible for this location. Cracking in this area will have to be completed from the outside only. Refer to , REHS7193 Special Instruction , "Procedure for the Inspection, Repair, and Component Replacement on the Frame of the 793F and the 793F Command For Hauling Off-Highway Trucks" for details.

Repair of Location 3

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Illustration 117	g06229649
View of Location 3

1. Access to the root or inside is not possible for this location. Cracking in this area will have to be completed from the outside only. Refer to , REHS7193 Special Instruction , "Procedure for the Inspection, Repair, and Component Replacement on the Frame of the 793F and the 793F Command For Hauling Off-Highway Trucks" for details.

Repair of Location 4

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Illustration 118	g06229658
View of Location 4 limits of accessibility (AA) 300 mm (12.0 inch)

1. Illustration 118 depicts a cross section of the RH FSSC showing the limits of reach and visibility for repair from both sides. From the edge of the cast-in brackets, visibility and reach is approximately 300 mm (12.0 inch) on the internal surface the same as for Location 1. The view shows the front half of the casting towards the front of the machine.

2. For any repairs in this area refer to the methodology outlined in the "Repair of Location 1" Section.

Appendix A - Tools

Note: Personal Protective Equipment (PPE) suitable for the work being performed during this repair must be worn.

Illustration 119	g06229700
View of Pneumatic Needle Peening Tool (Bundle)

Illustration 120	g06229704
View of Tungsten Carbide Bur Bit (PFERD Brand) Good for preparing the ends of the weld repair area

Illustration 121	g06229706
View of 7" 36 Grit Flexible Sanding Disc (3M Brand)

Illustration 122	g06229710
View of 5" 36 Grit Flexible Sanding Disc (3M Brand)

Illustration 123	g06229713
View of 4.5" Hard Aluminum Oxide Grinding Disc

Illustration 124	g06229715
View of Large Pneumatic Die Grinder with cutoff Wheel

Illustration 125	g06229722
View of cutoff Wheel 4.5" OD 1.5 mm (0.06 inch) thick

Illustration 126	g06229725
View of cutoff Wheel 3" OD 3.2 mm (0.13 inch) thick

Illustration 127	g06229726
View of 2" 36 Grit Flexible Sanding Disc (3M Brand)

Illustration 128	g06229737
View of 5" (PFERD Brand) Good for curved surfaces and corners.

Illustration 129	g06229739
View of Miscellaneous Stones (1/4" shank) Good for apex area and corners

Illustration 130	g06343393
View of long reach grinder 557-8548 Grinder

Illustration 131	g06343399
View of 557-8549 Collet (accessory for long reach grinder)

Illustration 132	g06343428
View of 557-8552 Abrasive Plug (accessory for long reach grinder)

Illustration 133	g06343443
View of 557-8553 Abrasive Cone(accessory for long reach grinder)

Illustration 134	g06229741
View of Reciprocating Saw Good for curves (where cutoff wheel will not work).

Appendix B - Ceramics

Check with local welding supplier for ceramics procurement options.

Note: The ceramics in the following Illustrations were purchased from Cerbaco, Ltd in New Jersey, USA (908–996–1333).

Illustration 135	g06229747

Illustration 136	g06229748

Illustration 137	g06229750

Illustration 138	g06229751

Illustration 139	g06229753

Illustration 140	g06229754

Illustration 141	g06229757
EW-105–4" x 500' High Temperature Tape

Note: The high temperature tape used was 4" wide and a 500' roll.

Appendix C - Fatigue Concepts

Illustration 142	g06229760

Illustration 142 identifies the various letter designations that represent the various weld joints and their fatigue classification. Weld class B is the best or highest class, which represents the highest number of cycles (or life) for a given stress range. Weld class W is the worst or lowest class, which represents the lowest number of cycles (or life) for a given stress range.

For this repair, weld classification C, E, F, and F2 are of particular importance.

Illustration 143	g06229768

Welded from one side only (open root or onto temporary backing such as ceramics) is shown in Illustration 143. The weld classification for this weld is F2 if the root or back side of the weld cannot be inspected or verified for quality. If the weld can be inspected and verified (and even repaired), then the weld classification is increased to an E. The reason for the down grade is that if the weld cannot be inspected and verified to be a quality root pass, then the weld is assumed to contain one or more defects (for example lack of fusion, lack of penetration, undercut, overlap). The highest stress concentration is at the weld root due to the presence of a defect or poor profile, therefore failure will come from the root.

Illustration 144	g06229771

A common root defect example is for this type of welding is shown in Illustration 144. You can see the difference in the root versus the cap profile. The small flank angle at the root causes a stress concentration that leads to crack initiation.

Illustration 145	g06229772

A second common root defect for this type of welding is lack of penetration. Refer to Illustration 145. Likewise a stress concentration is present at the notch in the root leading to crack initiation.

Illustration 146	g06229781

Welded from one side onto a permanent or steel backing is shown in Illustration 146. The weld classification for this weld is F. The stress concentration at the weld root is higher than at the weld toes, therefore failure will come from the root.

Illustration 147	g06229783

Welded from both sides, back welded from the opposite side, or welded from one side with a quality root pass is shown in Illustration 147. The weld classification for these welds is E. The main reason for class E is that there is accessibility to both sides to inspect, verify and repair (if needed). The stress concentrations are equal at all weld toes (both sides), so failure could come from any of the weld toes (either side).

Illustration 148	g06229788

Full penetration groove weld sanded flush on both sides is shown in Illustration 148. The weld classification for these welds is a C. This would include welding from one side onto a steel backing strip and then sanding the steel backing flush.

Note: The key to this classification is that all "geometric" stress concentrations like weld toes and weld roots have been removed because both sides are accessible and it is looking and behaving like a steel plate or a steel casting wall.

Illustration 149	g06229801

The graph in Illustration 149 shows the number of cycles (life) for each of the four weld classifications at a stress range of 150 MPa (21755 psi).

• Class F2 = ~375,000 cycles to failure

• Class F = ~525,000 cycles to failure

• Class E = ~1,000,000 cycles to failure

• Class C = ~2,750,000 cycles to failure

Clearly, access to both sides of the repair yields a better life.

Recent fatigue tests of class C welded coupons resulted in most of the failures occurring in the parent material outside of the weld.

Procedure for Front Suspension Support Material Build UP on 793 Off-Highway Trucks

The intent of this procedure is to reduce maintenance on location 1 of FSSC. This procedure is not recommended for all machines. If your machine is operating in a severe application and/or has experienced multiple repairs in location 1, then this procedure should be considered to reduce future maintenance on the casting at this location. This procedure is only to be performed by certified welders who have been trained on the use of the required tooling. This procedure provides an increase in material thickness on the front suspension support casting (FSSC).

This procedure should only be used after a crack has been identified during inspection at location 1. If a crack is identified the crack should first be repaired, refer to casting repair recommendations in , REHS7193 for partial through thickness repair or repair on location 1 for a through thickness repair located within this document.

If this procedure is performed pro-actively, without a crack present, the desired results may not be realized.

Note: If the aforementioned recommendation of this procedure being carried out after a crack identified is not followed and is instead performed pro-actively, it is recommended that the front suspension cylinder be removed so that the inside surface can be visually inspected. Utilize MT to verify or validate indications that are found during visual inspection. Any defects and/or weld repairs identified should be repaired and/or ground/sanded flush.

The cast steel material for 8X-3566 Support and 8X-3567 Support is a low carbon/manganese steel type that is readily weldable.

The cast steel material for 464-1100 Support and 464-1101 Support is a low carbon/manganese/vanadium steel type that is also readily weldable.

No preheat (above ambient temperature) is required for either material when welding in ideal conditions such as in a factory setting on new shot or sand blasted material. As a precaution a preheat/inter-pass will be required to offset field conditions.

Note: A 125° C (257° F) minimum preheat/inter-pass temperature is required for any welding on the locations identified in this procedure. Maximum inter-pass is 300° C (572° F).

When preheating by flame, the heat source should be removed for at least 1 min/inch of thickness and the temperature should be measured 75 mm (3.0 inch) from the center of the weld joint.

Weld starts/stops within a multi-pass weld shall be staggered and ground.

Inspection methods: Visual Testing (VT) and Magnetic Particle Testing (MT).

Note: Store all tooling inside and out of the elements. Proper storage will allow for the tooling to be used many times without the need to replace.

Illustration 150	g06271997
View of the front suspension support casting locations on the frame

The specific location where required material build-up is shown on the RH Front Suspension Support Casting (FSSC).

Note: Both the RH and LH FSSC can be completed. This document provides the steps to perform the material buildup procedure on the RH FSSC. The LH side material buildup will be the same as the RH side with two exceptions, the outline template and profile template. Each FSSC has an RH and LH outline template. The profile gages will fit into both the RH and LH profile template (only need one set of profile gages).

Right-Hand Side Front Suspension Support Casting

Illustration 151	g06272008
View of the specific location on the RH FSSC

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Illustration 152	g06272011
View of the area prepared (RH FSSC)

1. Make necessary repairs to location 1. Remove the paint and other foreign substances from the surface. Refer to Illustration 152.

   Note: For best results, if there has been a previous through thickness repair or it is suspected that a through thickness repair may have been done on the casting in this area, the front suspension cylinder should be removed so that the inside surface can be visually inspected. Utilize MT to verify or validate indications that are found during visual inspection. Any visible defects and/or weld repairs identified should be repaired and/or ground/sanded flush before proceeding.

   Note: Repair cracks per the casting repair recommendations in REHS7193 for partial through thickness repair or repair on location 1 for a through thickness repair located within this document.

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   Illustration 153	g06277642
   View of the outline template replica of material build-up required (T1) Outline template (RH)

   Note: The outline templates will not fit perfectly, due to casting profile tolerances. The goal is to find the best fit.

2. Outline template (RH) (T1) shown in Illustration 153 represents the thickness and profile of the material required to build up the surface. The front and back of outline template (RH) (T1) shown for reference.
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   Illustration 154	g06272774
   View of the outline template (RH) (T1) Outline template (RH)

3. Orient outline template (RH) (T1) on the RH FSSC as shown in Illustration 154.
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   Illustration 155	g06272776
   View of the traced outline

4. Trace the outline of outline template (RH) (T1) and remove the template. Refer to Illustration 155.
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   Illustration 156	g06272808
   View of the profile template and profile gages (T3) Profile template (RH) (T4) Profile gages

   Note: The profile template and profile gages are numbered to assist with assembly and identification.

5. Assemble profile gages (T3) into profile template (RH) (T3) as shown in Illustration 156.
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   Illustration 157	g06272818
   View of the profile template and profile gages in position

6. Fit assembled profile template (T3) onto the area as shown in Illustration 157.
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   Illustration 158	g06272822
   View of the ends of the profile gages marked

7. Mark each of the ends of the profile gages. Refer to Illustration 158.
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   Illustration 159	g06272826
   View of the profile gage ends marked onto the casting

8. Remove the profile template (RH). Illustration 159 depicts the markings after the plastic box fixture is removed.
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   Illustration 160	g06272844
   View of MT inspection

9. If not previously performed after crack repair was completed, MT inspect the area to ensure that no defects are present on the surface or near the surface. If unsure MT inspect the area to ensure that no defects are present. Make repairs as needed.
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   Illustration 161	g06273034
   View of a bur bit used to identify the outline

10. Use a rotary bur bit to trace over the outline marking. The grinding does not need to be deep, but shallow 0.5 mm (0.02 inch) to 1.0 mm (0.04 inch). The ground line will be a reference to guide the welder. Refer to the example in Illustration 161.
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    Illustration 162	g06273071
    View of surface welds

11. Build up the surface of the casting by applying surface welds. Surface welds can be applied in the vertical up or horizontal positions. The amount of material added per layer is approximately 3 mm (0.12 inch). Refer to Illustration 162.
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    Illustration 163	g06273075
    View of the weld vertical up pass

12. Weld vertical up pass in the shallow groove produced by the rotary bur bit. Refer to Illustration 163.
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    Illustration 164	g06273079
    View of the first layer welded

13. Weld horizontal surfacing welds from bottom to top for the outlined area. Refer to Illustration 164.

    Note: Welding shown in Illustration 164 was from right to left. Welding was started on the line produced by the rotary bur bit and welding was ended on top of the completed vertical weld.

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    Illustration 165	g06273092
    View of the welded outline of the first layer compared to the outline template (RH) (T1) Outline template (RH)

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    NOTICE
    Ensure that the area has cooled before placing the outline template (RH) on top of the first weld layer. Do not place the outline template (RH) over a hot surface or outline template will melt.

14. The first weld layer will likely extend slightly past the outline template (RH) as shown in Illustration 165.

    Note: This step is not required, but shows desired result after first weld layer is completed.

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    Illustration 166	g06273156
    View of measuring from the top and bottom (D1) 55 mm (2.20 inch) up from the bottom (D2) 10 mm (0.40 inch) down from the top

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    Illustration 167	g06273172
    View of measuring in from each side (D3) 30 mm (1.20 inch) from the right side (D4) 5 mm (0.20 inch) from the left side

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    Illustration 168	g06273174
    View of the outline for the second weld layer

15. For the second weld layer, use the dimensions in Illustration 166 and Illustration 167. Measure in from each edge of the first weld layer to create the required outline. Refer to Illustration 168 for resulting outline for second weld layer.
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    Illustration 169	g06273188
    View of the outline identified using a bur bit

16. Use the rotary bur bit to grind a trace line over the marked outline for the second weld layer.
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    Illustration 170	g06273202
    View of the vertical up pass for second layer

17. Repeat the same steps as for the previous layer. Weld a vertical up pass in the shallow groove produced by the rotary bur bit.
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    Illustration 171	g06273582
    View of the horizontal welding for second weld layer

18. Weld horizontal surfacing welds from bottom to top for the outlined area. Refer to Illustration 171.
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    Illustration 172	g06273595
    View of dimensions for the third weld layer outline (D1) 10 mm (0.40 inch) measure from the outside edge of the First weld layer (D2) 10 mm (0.40 inch) measure from the outside edge of the First weld layer (D3) 15 mm (0.60 inch) measure from the outside edge of the Second weld layer (D4) 75 mm (3.0 inch) measure from the outside edge of the First weld layer

19. For the third weld layer, use the dimensions in Illustration 172 and measure in and mark the four sides to create the required outline.
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    Illustration 173	g06273599
    View of the outline identified using a bur bit

20. Use rotary bur bit to trace over the outline markings for third weld layer.
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    Illustration 174	g06273630
    View of the vertical up weld pass

21. Repeat the same steps as for the previous layer. Weld a vertical up pass in the shallow groove produced by the rotary bur bit.
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    Illustration 175	g06273650
    View of the horizontal welding of third weld layer

22. Weld horizontal surfacing welds from bottom to top for the outlined area. Refer to Illustration 175.
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    Illustration 176	g06273655
    View of dimensions for the fourth weld layer outline (D1) 5 mm (0.20 inch) measure from the outside edge of the Third weld layer (D2) 10 mm (0.40 inch) measure from the outside edge of the Third weld layer (D3) 40 mm (1.60 inch) measure from the outside edge of the Third weld layer (D4) 20 mm (0.80 inch) measure from the outside edge of the Third weld layer

23. For the fourth weld layer, use the dimensions in Illustration 176 and measure in and mark the four sides to create the required outline.
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    Illustration 177	g06273701
    View of the outline identified using a bur bit

24. Use a rotary bur bit to trace over the outline marking for the fourth weld layer.
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    Illustration 178	g06273713
    View of the vertical up weld pass

25. Repeat the same steps as for the previous layer. Weld a vertical up pass in the shallow groove produced by the rotary bur bit.
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    Illustration 179	g06273737
    View of the horizontal welding of fourth weld layer

26. Weld horizontal surfacing welds from bottom to top for the outlined area. Refer to Illustration 179

27. The bulk of the welding is now complete, but minor additions may be required as sanding/grinding occurs.
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    Illustration 180	g06273753
    View of profile template (RH) (T3) and profile gages (T4) ( T3) Profile template (T4) Profile gages

28. Before starting sanding/grinding to profile, it is necessary to understand the identification and position of each profile gage (T4). There are two vertical gages 9–10 and 11–12 and four horizontal gages 1–2, 3–4, 5–6 and 7–8.
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    Illustration 181	g06274263

29. The final shape will be controlled by four main profile gages. Both vertical and horizontal gages 3–4 and 5–6 are critical. Refer to Illustration 181.
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    Illustration 182	g06274270
    View of aluminum profile gages 9–10 and 11–12

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    Illustration 183	g06274272
    View of aluminum profile gages 3–4 and 5–6

30. All six of the profile gages can be removed from the profile template (RH). The six profile gages can be used independently to determine where and how much material to sand/grind. The four critical profile gages are shown in Illustration 182 and Illustration 183.
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    Illustration 184	g06274473
    View of a high spot for profile gage 9–10

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    Illustration 185	g06274497
    View of a high spot for profile gage 11–12

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    Illustration 186	g06274507
    View of a high spot for profile gage 3–4

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    Illustration 187	g06274520
    View of a high spot for profile gage 5–6

31. Using the four profile gages, individually place the gages in the appropriate position (using previous marks) and check for high spots. Refer to Illustration 184 through Illustration 187.

    Note: Identify high spots with a black permanent marker.

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    Illustration 188	g06274551
    View of sanding in process

32. Illustration 188 demonstrates the goals for the initial sanding operation in process.

    Note: In general, the initial goal of sanding is to blend all four weld layers into one layer. Afterward, the aluminum profile gages can be used to identify the high and low spots.

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    Illustration 189	g06274556
    View of manipulating the profile gage for best fit on the 3D printed profile

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    Illustration 190	g06274558

33. Before removing too much material, it is important to emphasize that profile gages (T4) requires some knowledge of orientation. Profile template (T3) places each of the profile gages at certain angles. It is necessary to understand how each of the profile gages should be held when judging where and how much to grind. The easiest way is to utilize the original outline templates (T1) and (T2)) which represents the material build-up and see how the profile gages best fit the outline templates based on orientation. Then use that orientation on the actual part to judge the profile.

    Illustration 189 demonstrates the difference in gap when orienting the profile gage perpendicular versus the angle that the profile template would provide.

    Illustration 190 shows the same comparison for the actual part. Notice the large difference in gap.

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    Illustration 191	g06274586
    View of area of profile gage that is not part of the desired profile

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    Illustration 192	g06274609
    View of the areas of the profile gage that is not part of the desired profile

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    NOTICE
    Illustration 191 indicates an area near the end that is only for clearance for the cast flange. This area is not to be built up by welding.

34. Another important concept is that there are areas of profile gages (T4) that do not represent the desired profile.

    In addition, the profile gages are intended to check the profile of the weld build-up, not beyond. As Illustration 192 indicates, the ends of the profile gages beyond the weld build-up do not apply.

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    Illustration 193	g06274627
    View of checking and marking the profile

35. Continuously use the different profile gages to check your progress as material is removed, ensuring that material is being removed in the correct places. Refer to Illustration 193.
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    Illustration 194	g06274652
    View of a small addition of material required

36. On occasion it may be that some additional material is needed to reduce gaps. Adding material is acceptable, Illustration 194 shows an area where more material was necessary.
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    Illustration 195	g06274653
    View of radii that require curved flap disc

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    Illustration 196	g06274658
    View of the curved flap discs

37. When sanding the radii shown in Illustration 195, it is necessary to use the recommended sanding discs.

    Note: Preferred Polifan Flap Discs (part# EDP 67216 and EDP 67359) for use with a 4.5 inch to 5 inch angle grinder.

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    Illustration 197	g06274857
    View of aluminum profile gages 9–10 and 11–12

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    Illustration 198	g06274860
    View of aluminum profile gages 3–4 and 5–6

38. Continue the process of evaluating the profile using profile gages (T4), marking the high spots and sanding to profile until the desired overall profile has been achieved.

    Note: The main objective is to achieve the approximate profile for the four critical profile gages. A gap of 2 mm (0.08 inch) or less is sufficient as long as the profile has no abrupt high or low spots.

    Illustration 197 and Illustration 198 show the final profiles that were achieved in the preparation of this procedure.

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    Illustration 199	g06274926
    View of MT inspection

39. Once the desired profile has been achieved, check the surface area using magnetic particle (MT). Refer to Illustration 199.

40. If required, make any necessary repairs and recheck until no rejectable indications are present.
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    Illustration 200	g06274963

41. Needle peen the entire surface similar to what is shown in Illustration 200.

Left-Hand Side Front Suspension Support Casting

Illustration 201	g06275044

The LH side weld build-up will be the same as the RH side with two exceptions, the outline template (T2) and the profile template (LH) (T3). Each FSSC has an RH and LH outline template. The profile gages will fit in both the right and left-hand profile templates (only need one set).

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Illustration 202	g06275040

Note: The instructions for the LH side are the same as the RH side but will not be as detailed. If anything is not clear, refer to the RH side FSSC for more specific details.

1. The specific location for the LH side is shown in Illustration 202.
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   Illustration 203	g06275047
   View of the area prepared (LH FSSC)

2. Make necessary repairs to location 1. Remove the paint and other foreign substances from the surface. Refer to Illustration 203.

   Note: Repair cracks per the casting repair recommendations in , REHS7193 for partial through thickness repair or repair on location 1 for a through thickness repair located within this document.

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   Illustration 204	g06275294
   View of the 3D printed profile in place (T2) 3D printed profile

   Note: The plastic replicas will not fit perfectly, due to casting profile tolerances. The goal is to find the best fit.

3. Orient outline template (LH) (T2) on the LH FSSC as shown in Illustration 204.
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   Illustration 205	g06275306
   View of the traced outline

4. Trace the outline of the outline template (LH). Refer to Illustration 205.
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   Illustration 206	g06275346
   View of the plastic box fixture and gages in position (T3) Profile template (T4) Profile gages

5. Assemble profile gages (T4) in profile template (T3) and fit profile template to the area as shown in Illustration 206.

6. Mark each end of the profile gages and remove the profile template.

7. If not previously performed after crack repair was completed, MT inspect the area to ensure that no defects are present on the surface or near the surface. Make repairs as needed.
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   Illustration 207	g06275376
   View of a bur bit used to identify the outline for weld first weld layer

8. Use a rotary bur bit to trace over the outline marking. The grinding does not need to be deep, but shallow 0.5 mm (0.02 inch) to 1.0 mm (0.04 inch). The ground line will be a reference to guide the welder. Refer to the example in Illustration 207.

9. The procedure for building up the area of the casting will be identical to the procedure for the RH side. Build up the surface of the casting by applying several layers of surface welds.
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   Illustration 208	g06275377
   View of the first weld layer

10. Weld a vertical up pass in the shallow groove produced by the rotary bur bit. Then weld horizontal surfacing welds from the bottom to the top for the outlined area. When completed the first layer should appear similar to the weld shown in Illustration 208.
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    Illustration 209	g06275421
    View of the marked outline for second weld layer (D1) 10 mm (0.40 inch) down from the top (D2) 30 mm (1.20 inch) in from the left (D3) 55 mm (2.20 inch) up from the bottom (D4) 5 mm (0.20 inch) in from the right

11. Use the dimensions shown in Illustration 209 to measure and mark for the second layer of weld.
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    Illustration 210	g06275443
    View of a bur bit used to identify the outline for weld second weld layer

12. Use a rotary bur bit to identify outline marking.
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    Illustration 211	g06275680
    View of the second weld layer

13. Weld a vertical up pass in the shallow groove produced by the rotary bur bit. Then weld horizontal surfacing welds from the bottom to the top for the outlined area. When completed the first layer should appear similar to the weld shown in Illustration 211.
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    Illustration 212	g06275709
    View of the marked outline for third weld layer (D1) 10 mm (0.40 inch) down from the top (D2) 10 mm (0.40 inch) in from the left (D3) 75 mm (3.00 inch) up from the bottom (D4) 15 mm (0.60 inch) in from the right

14. Use the dimensions shown in Illustration 212 to measure and mark for the second layer of weld.
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    Illustration 213	g06275712
    View of a bur bit used to identify the outline for weld third weld layer

15. Use a rotary bur bit to identify outline marking.
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    Illustration 214	g06275716
    View of the third weld layer

16. Weld a vertical up pass in the shallow groove produced by the rotary bur bit. Then weld horizontal surfacing welds from the bottom to the top for the outlined area. When completed the first layer should appear similar to the weld shown in Illustration 214.
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    Illustration 215	g06275732
    View of the marked outline for fourth weld layer (D1) 10 mm (0.40 inch) down from the top (D2) 40 mm (1.60 inch) in from the left (D3) 20 mm (0.80 inch) up from the bottom (D4) 5 mm (0.20 inch) in from the right

17. Use the dimensions shown in Illustration 215 to measure and mark for the second layer of weld.
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    Illustration 216	g06275745
    View of a bur bit used to identify the outline for welding the fourth weld layer

18. Use a rotary bur bit to identify outline marking.
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    Illustration 217	g06275806
    View of the fourth weld layer

19. Weld a vertical up pass in the shallow groove produced by the rotary bur bit. Then weld horizontal surfacing welds from the bottom to the top for the outlined area. When completed the first layer should appear similar to the weld shown in Illustration 217.
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    Illustration 218	g06275813
    View of low spots identified

20. Once the four layers of welding have been completed, sand and blend all four weld layers into one layer. Some additional welding may be required prior to using the aluminum profile gages.

    Illustration 218 is an example of the four weld layers blend sanded into one layer, but some low spots have been identified.

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    Illustration 219	g06275815
    View of low spots filled by welding

21. Instead of continuing to blend sand, fill in the low spots by welding to avoid removing too much material. Refer to Illustration 219.

22. Blend sand the additional weld metal and then use the aluminum profile gages to determine high and low spots.

    Note: Refer to the RH FSSC section for detailed instructions on how to use the aluminum profile gages.

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    Illustration 220	g06275893
    View of using the vertical aluminum profile gage 9–10 to identify a high spot

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    Illustration 221	g06275897
    View of the horizontal profile gage 5–6 used to identify high spots

23. Illustration 220 and Illustration 221 show using the vertical and horizontal profile gages to identify a high spot requiring more sanding.

    Note: The high spot is identified by both gages in the vertical and horizontal directions.

24. Continue the process of evaluating the profile using profile gages, marking the high spots and sanding to profile until the desired overall profile has been achieved.

    Note: The main objective is to achieve the approximate profile for the four critical profile gages. A gap of 2 mm (0.08 inch) or less is sufficient as long as the profile has no abrupt high or low spots.

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    Illustration 222	g06275923
    View of the completed profile on the LH FSSC

25. Once the desired profile has been achieved, check the surface area using MT. If required, make the necessary repairs and recheck until no rejectable indications are found.
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    Illustration 223	g06275924

26. Needle peen the entire surface similar to what is shown in Illustration 223.