Weld Repair and Rework Procedures for the GLL Grapple Head {0679, 6307, 6700} Caterpillar

Introduction

The forestry products that are equipped with GLL grapples have a repair procedure to the cracks on the 208-8049 Plate . Follow the procedure that is described below in order to repair the GLL Grapple Head Assembly.

Do not perform any procedure in this Special Instruction until the information has been read and understood.

Repair the Cross Brace

Remove the Cross Brace

1. Attach supports (1) across the body of the grapple in order to prevent the misalignment of the pin bore.

2. Use a grinder or another appropriate cutting device in order to remove cross brace (2) .

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Illustration 1	g01938313

3. Chamfer a 45 degree angle to inside edge (3) and outside edge (3) of the grapple housing.

Illustration 2	g01938317

Fabricate the Cross Brace

1. Fabricate one cross brace (4). Use ASTM A572 Grade 50 or equivalent material. Refer to Illustration 3 for plate dimensions.

Illustration 3	g01938341

Install the Cross Brace

1. Prepare the area for welding. For information on welding, refer to Special Instruction, REHS1841, "General Welding Procedures".

2. Position cross brace (2) on the grapple housing. Tack weld cross brace (2) in place.

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Illustration 4	g01938753

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Illustration 5	g01938755

3. Attach cross brace (2) to the grapple housing. Refer to Illustration 5 for size of the weld and the location.

Note: Extra precautions should be taken in order to avoid the misalignment of the pin bore.

Reinforce the Pin Boss

Fabricate the Reinforcement Plate

1. Fabricate two reinforcement plates (5) of steel that meets ASTM A572 Grade 50 or equivalent material. Refer to Illustration 6 for plate dimensions. Larger images are available at the end of this document.

Illustration 6	g01939016

Install the Reinforcement Plate

1. Prepare the area for welding. For information on welding, refer to Special Instruction, REHS1841, "General Welding Procedures".

2. If necessary, align the pin boss of the cylinder barrel. Refer to Illustration 7.

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Illustration 7	g01939056

3. Align the hole in reinforcement plate (2) with the bolt hole of the cylinder pin. The 8T-6383 Bolt may be used to help align the holes. Align the end of reinforcement plate (2) with the side plate of the grapple. Tack weld the side plate in place. Refer to Illustration 7 and Illustration 8.

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Illustration 8	g01939074

4. Attach reinforcement plate (5). Use a bevel groove weld in four places (7). Refer to Illustration 8 for the weld location.

   Note: Extra precautions should be taken in order to avoid the misalignment of the pin bore.

5. If necessary, align the boss of the cylinder pin.

6. Repeat Steps 1 through 5 for the opposite cylinder mounting.