Installing Additional Gussets and Improved Support Plate on Certain Quick Couplers{6129} Caterpillar

Introduction

This special instruction outlines the procedure to install additional gussets and an improved support plate on the 315-6334 Quick Coupler Gp on the above listed machines.

Do not start any work or order any parts until you have read the material and understand the procedure.

Reference

For general welding procedures reference Special Instruction, REHS1841, "General Welding Procedures".

Required Parts

The following repair parts for this repair must be fabricated:

• (1) Plate fabricated from ASTM A514 or equivalent. Refer to Illustration 1.

• (2) Long tubes made from structural tubing. Refer to Illustration 2.

• (1) Short tube made from structural tubing. Refer to Illustration 3.

• (1) Plate fabricated from ASTM A514 or equivalent. Refer to Illustration 4.

Note: Some machines may have had the parts in Illustrations 1, 2, and 3 previously installed. If you are only installing the doubler plate in Illustration 4, refer to the note following Step 5 in the ""Repair Procedure" ".

Illustration 1	g03737403
(R1) 20 mm (0.79 inch) radius (R2) 125 mm (4.92 inch) radius (R3) 25 mm (0.98 inch) radius (R4) 5 mm (0.20 inch) radius (R5) 24 mm (0.94 inch) radius (R6) 24 mm (0.94 inch) radius (R7) 8 mm (0.31 inch) radius (A) 597 mm (23.5 inch) (B) 307 mm (12.1 inch) (C) 247.6 mm (9.75 inch) (D) 35.4 mm (1.39 inch) (E) 64.9 mm (2.56 inch) (F) 30.9 mm (1.217 inch) (G) 48 mm (1.9 inch) (H) 71.4 mm (2.81 inch) (J) 126.1 mm (4.96 inch) (K) 388 mm (15.3 inch) (L) 305.5 mm (12.03 inch) (M) 67 mm (2.6 inch) (N) 12.1 mm (0.48 inch) (P) 8 mm (0.31 inch)

Illustration 2	g03737409
(R) 264 mm (10.39 inch) (S) 101.6 mm (4.00 inch) (T) 10 mm (0.40 inch)

Illustration 3	g03737416
(S) 101.6 mm (4.00 inch) (T) 10 mm (0.40 inch) (U) 101 mm (3.98 inch)

Illustration 4	g03737428
(AA) 20 mm (0.80 inch) diameter hole (two places) (BB) 127.1 mm (5.00 inch) (CC) 10 mm (0.40 inch) radius (DD) 83.6 mm (3.30 inch) (EE) 45.8 mm (1.80 inch) (FF) 28.5 mm (1.12 inch) (GG) 40 mm (1.60 inch) (HH) 197.3 mm (7.77 inch) (JJ) 225.8 mm (8.89 inch) (KK) 254.2 mm (10.00 inch) (LL) 8 mm (0.31 inch) (MM) 20 mm (0.77 inch)

Repair Procedure

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Personal injury can result from flame cutting or welding on painted areas. The effect of gasses from burned paint is a hazard to the person doing the cutting or welding. Do not flame cut or weld on painted areas.

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Illustration 5	g03716864

1. Use a suitable cutting method to remove the existing plate from the coupler. Remove any burrs or slag produced from cutting.

2. Gouge and reweld all cracks 100%. Refer to Special Instruction, REHS1841, "General Welding Procedures" for welding procedures.

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Illustration 6	g03716865

3. The illustration above shows where the structural tubing will be attached. Clean areas to be welded to remove paint and dirt. Clean areas where cutting and repairing was performed.

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Illustration 7	g03716866
(W1) 12 mm (0.5 inch) fillet weld (2) Long tube fabricated as in Illustration 2 (3) Short tube fabricated as in Illustration 3

4. Bevel both ends of plates (2) and plate (3). Install the tubes as shown in Illustration 7. Ensure that each piece fits tightly between the plates before welding. (Grind to fit.)

5. Finish weld tubes (2) and (3) as shown in Illustration 7.

   Apply a 12 mm (0.5 inch) fillet weld all around both ends of all three tubes.

   Apply a 12 mm (0.5 inch) fillet weld along the bottom of each tube on both sides.

   Note: If the tubes were previously installed with 8 mm (0.31 inch) fillet welds, upsize the welds to 12 mm (0.5 inch). For up sizing existing welds, if there is no cracks in or around the weld, add 2 or 3 more passes of weld to build up to 12 mm (0.5 inch). If cracks are present, then gouge out and re-weld completely. Do Not cut off plate (1) shown in Illustration 8 to upsize the welds covered by the plate. Only upsize the welds on the accessible parts of the tubing. Continue to Step 10 for installation of the doubler plate.

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Illustration 8	g03716868
(1) Plate fabricated as in Illustration 3 (W2) J Groove weld flush with surface of plate (1) (W3) 8 mm (0.31 inch) fillet weld

6. Locate plate (1) by centering the plate side to side as shown in Illustration 8. Tack weld plate (1) into position.

7. Finish weld plate (1) as shown in Illustration 8.

   Finish weld the top and bottom with a J-Groove weld. Finish the weld flush with the surface of the plate.

   Apply an 8 mm (0.31 inch) fillet weld along the improved radius on both edges of the plate securing the plate to tubes (2) .

   Apply an 8 mm (0.31 inch) fillet weld along both straight edges of plate (1). Repeat this weld on the inside edge of plate (1) also. Refer to Illustration 8.

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Illustration 9	g03716869
View using hidden lines to show plates on other side of plate (1) (W3) 8 mm (0.31 inch) fillet weld

8. Finish weld two gussets to plate (1) as shown in Illustration 9. Apply an 8 mm (0.31 inch) fillet weld on both sides of two gussets.

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Illustration 10	g03719955
Location of weld that is under the new doubler plate before installing doubler plate (W3) 8 mm (0.31 inch) fillet weld

9. Finish weld the plate below the steel tubing to plate (1) as shown in Illustration 10 before installing the doubler plate. This weld will be an 8 mm (0.31 inch) fillet weld. The length of this weld is dependent on how far the weld equipment will allow the welder to reach.

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Illustration 11	g03730428
Location of doubler plate (W3) 8 mm (0.31 inch) fillet weld

10. Install the doubler plate as shown in Illustration 11. Position the bevel to clear the weld performed in Step 9.

11. Finish weld the doubler plate as shown in Illustration 11.

    Apply an 8 mm (0.31 inch) fillet weld around all sides of the doubler plate.

    Apply an 8 mm (0.31 inch) fillet weld around the inside of three holes/slots.