Installation of Mechanically Attached Sidebar Protectors on Loader Bucket{6101, 6102, 6817} Caterpillar

Wheel Loader: All Medium Wheel Loaders

Introduction

This special instruction contains procedures and information for installation of Mechanically Attached Sidebar Protectors on loader buckets having sidebars with curved front (Performance Series).

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

Illustration 1	g03805685
Typical Wheel Loader Bucket with curved front on Sidebar (A) Sidebar with curved front (B) Mechanically Attached Sidebar Protector

Illustration 2	g03806029
Assembly of parts in Protector GP and Plug (C) Plug (E) Base (F) Protector (H) Retainer

Mechanically attached protectors are available in three different sizes based on thickness of sidebar. Refer to Table 1. A base welded on to the sidebar and compression retainer are used to mount a protector on the sidebar. A plug is used to protect the compression retainer from dust and debris.

Installation Instructions

1. Select the Protector GP part number for the bucket. Refer to Table 1.

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Illustration 3	g03806055
Rear view of Protector (R1) Rest pad (R2) Rest pad (G) Strap gap (D1) Dovetail-shaped projections

2. Attach 1 mm (0.04 inch) thick shim (maximum size of 20 mm (0.79 inch) x 16 mm (0.63 inch)) on each of two Rest pads (R1) and (R2) on the protector using tape or grease. Refer to Illustration 3.

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Illustration 4	g03806166
Bottom view of Base (J) J-groove for welding (P) Groove for fillet welding (D2) Dovetail-shaped grooves (S1) Contact surfaces on Base with Sidebar (M) Resting surface for Retainer on Base

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Illustration 5	g03806228
Assembling Protector on Base

3. Slide the protector into the base. Refer to Illustration 5.

   Note: Dovetail projections (D1) of protector seat on the dovetail recesses (D2) of the base. Refer to Illustration 3 and 4.

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Illustration 6	g03806239
Bottom view of Base, Protector, and Retainer in assembly

4. Insert the retainer into the base as shown in Illustration 6 such that two ends of the retainer rest on surfaces (M) in base. Refer to Illustration 4.

5. Locate the area on sidebar where Protector Gp will be installed. All mounting surfaces on sidebar and base should be free of dirt, paint, and debris.

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Illustration 7	g03806251
Side view of bucket installed with Protector GP (R3) Front surface on Sidebar which contacts rest pads on Protector (S2) Side surface of Sidebar which contacts Base at (S1) (A) Sidebar (F) Protector (X) Flush bottom of protector along this line (Y) Location for weld between sidebar plate and corner LH/RH (Z) Corner RH

6. Slide the assembly in Step 4 over the sidebar with the base on the outside of the bucket. The sidebar surface (R3) shown in Illustration 7 should make hard contact on the shims on protector rest pads (R1) and (R2). Contact surfaces ( (S1) shown in Illustration 4) on base has hard contact with sidebar side surface ( (S2) shown in Illustration 7). Adjust position of assembly to flush bottom surface of protector with bottom surface of sidebar (above the weld between sidebar and corner LH/RH). Refer to Illustration 7.

7. Preheat all locations to be welded on sidebar and base to a minimum temperature of 150° C (300° F). During welding, interpass temperature should be monitored and kept in the range of 150° C (300° F) to 232° C (450° F).

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Illustration 8	g03806279
Locations for tack welding Base to Sidebar (A) Sidebar

8. Tack weld base on sidebar at two ends in root of J-groove (shown in Illustration 8). If required, use a spacer / combination of spacers in between protector and corner LH/RH to support protector assembly during tack welding.

   Note: The gap between sidebar and base should be minimized

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Illustration 9	g03806298
Location to insert pry bar and direction of push to remove Retainer from Base

9. To remove retainer from base, insert a small pry bar between the base and retainer (location shown in Illustration 9). The width of the point of the pry bar should be 8 mm (0.31 inch). The curved portion of the pry bar should face toward the retainer. Push the pry bar away from retainer (note the direction of push shown in Illustration 9). Retainer will compress and go over the center of base such that one end portion of retainer comes out of base. After removing the retainer fully, remove protector from base. Prevent base from getting deformed / deflected from original position during removal of retainer and protector. Remove the shims from protector.

10. Inspect the surfaces to be welded on sidebar and base for availability of sufficient interpass temperature. The minimum interpass temperature is 150° C (300° F) and the maximum interpass temperature is 232° C (450° F). If required, preheat the surfaces again to achieve specified interpass temperature.

11. Complete welding on base at locations (J) and (P) shown in Illustration 4. The J-groove weld and fillet weld on base (weld size: 15 mm (0.59 inch)) must be achieved in 3 passes at each location to ensure that proper weld strength is achieved. Make one pass at a time in each location in order to avoid excess heat build-up. If required, use C-clamp to hold base to sidebar during welding.

12. Allow all finished welds to slow cool.

13. Mount protector on base as in Step 3.

14. Install one end of the retainer under the resting surface (M) (shown in Illustration 4) on base.

15. Insert the pry bar in between base and retainer with curved portion facing toward the retainer. Push the pry bar toward the retainer. After the retainer compresses and the loaded end of retainer goes over center, the retainer will expand and fully snap into position.

16. Assemble the plug on the retainer. Refer to Illustration 2.

    Note: Shims are used in between protector and sidebar before tack welding of base to ensure repeatability of assembly of protector and retainer on base.

    Note: 138-0006 Retainer cannot be reused if out of flatness by more than 2 mm (0.08 inch) or if there is any plastic deformation.

    Note: 138-0006 Retainer cannot be reused if the retainer measures less than 87 mm (3.43 inch).

    Note: Do not weld on sides of base as any welds in these locations would interfere with the protector during assembly.

Weld Information

1. Read and understand the instructions from the supplier and the safety practices of your employer. Provide fresh air circulation to the welding helmet in order to avoid any illnesses that can be caused by long-term exposure to the welding fumes. The fresh air circulation will also remove any exhaled carbon dioxide that may be trapped by the welding helmet. Use proper eye protection, ear protection, and body protection while preparing the surfaces and while you are welding on the surfaces. Do not touch live electrical parts. Use a welding helmet with a filter plate that is at least Shade-11. Auto-darkening helmets are recommended as these helmets eliminate neck-strain from "helmet flipping" while greatly increasing the accuracy of electrode placement.

2. All welders must be qualified for fillet welding that is outlined in the current ANSI/AWS D14.3. The process of qualification for the Shielded Metal Arc Welding (SMAW) should be done in the vertical position. Prior to welding, the process must have been used during the last 6 months. Welding qualifications must be documented and current. The alternate process could be Flux Cored Arc Welding (FCAW).

3. Cleanliness: Areas that will be subject to welding must be free of paint, rust, grease, oil, scale, and slag. Contamination by these components can cause weld cracking, weld porosity and lower weld strength. Remove the slag and impurities after every pass.

4. Low hydrogen weld consumables: Use low hydrogen weld consumables with a diffusible hydrogen rating of no more than 5 ml/100 grams of weld deposit to prevent cracking due to hydrogen embrittlement. (Hydrogen embrittlement is a failure mode of steels caused by the introduction of hydrogen gasses into the steel at high temperatures, such as when welding. Hydrogen can be introduced due to the presence of moisture, high humidity, or incorrect weld consumables. The hydrogen infiltrates the steel, creating internal stresses, which lowers the strength and ductility of the steel) Recommended stick electrode for SMAW is E7018 (ANSI/AWS A5.1) and recommended wire electrode for FCAW is E71T-1 or E70T-5 (ANSI/AWS A5.20).

5. Preheat temperature: Apply proper amount of preheat before welding to ensure a good weld. Preheat helps to prevent distortion of the part due to uneven heating and helps welding by requiring less heat input from the welder. Preheating is critical on larger parts, where the large mass can rapidly remove heat from the welding area. A more uniform heat application can be obtained if the preheating is applied on the side opposite of the side to be welded. On large plates, preheat should extend 50-75mm (2 – 3 inch) beyond the weld.

6. Interpass temperature: Maintain an even temperature distribution while welding to help prevent distortion and improve weld quality. Inter-pass temperatures should be monitored and kept in the same temperature range as preheating. Care should be taken with large parts which could take longer to get up to temperature during preheat and may hold more heat once the parts are hot.

7. Slow cooling after welding: After welding is completed, the parts should be allowed to slow cool to prevent distortion and cracking. Slow cooling helps prevent distortion by eliminating uneven temperature distributions and allows internal stresses developed by weld shrinkage to dissipate. Additionally, slow cooling the parts gives a greater amount of time for hydrogen to escape from the steel, which helps to prevent hydrogen embrittlement. All welded components should be kept out of cool ambient air and drafts caused by fans, which can increase the cooling rate. Thermal blankets can also be used to ensure slow cooling.

8. The welds shall be free from cracks, porosity, undercut, and incomplete fusion. All weld quality should conform to ANSI/AWS D14.3.