Installation Procedure For Mounting Blocks{0679, 6502} Caterpillar

Excavator: All

Introduction

This Special Instruction provides the installation procedure for the mounting blocks for the auxiliary lines on 311-385 Caterpillar sticks. The following procedure describes the preferred welding procedure that should be used unless there is not enough area in order to perform the weld.

Reference

• Reference Service Guide, SEBD0512, "Caterpillar Service Welding Guide"

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

Welding Requirements

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Personal injury or death can result from fumes, gases and ultraviolet rays from the weld arc. Welding can cause fumes, burn skin and produce ultraviolet rays. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing area. Wear eye, ear and body protection before working. Protect yourself and others; read and understand this warning. Fumes and gases can be dangerous to your health. Ultraviolet rays from the weld arc can injure eyes and burn skin. Electric shock can cause death. Read and understand the manufacturer's instructions and your employer's safety practices. Do not touch live electrical parts. See "American National Standard Z49.1, Safety in Welding and Cutting" published by the American Welding Society. American Welding Society 2501 N.W. 7th Street Miami, Florida 33125 See "OSHA Safety and Health Standards, 29 CFR 1910", available from U.S. Department of Labor. U.S. Department of Labor Washington, D.C. 20210

Welding quality is critical to the success of the installation procedures. Welds must be smooth and continuous. Do not undercut the welds. Grind the ends of the welds to a smooth radius.

All electrodes must be completely dried. The electrodes can be dried by heating the electrodes to 300°C (572°F). The electrodes must be dried for at least 30 minutes.

Do not weld in windy conditions. Do not weld when temperatures are below 16°C (60°F).

Penetration characteristics may vary greatly depending on the following conditions:

• Electrode diameter

• Shielding gas

• Welding current

• Plate thickness

The following items also affect the welds:

• Geometry of welded joints

• Surface conditions

• Composition of the base metal and of the electrode

A root pass should be applied before each weld is finished.

Maintain a 3 mm (0.12 inch) minimum root opening on all cross welds and circle welds.

All welds to the stick must be welded in the direction from the rear of the stick toward the front of the stick.

For more welding information, consult the Caterpillar Service Welding Guide, SEBD0512.

Preparing the Metal for Welding

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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.

All grease, paint, and foreign objects must be removed before welding. Any of these materials will discharge gas which will cause porosity in the weld deposit. Water and rust will cause hydrogen embrittlement. Hydrogen embrittlement causes cracks in the weld deposit.

Remove foreign objects with a wire brush, a buffer, or a grinder. Shot blasting the appropriate areas will also remove foreign material.

Remove any oil or grease with a Caterpillar approved solvent.

Welding on Machines and Engines with Electronic Controls

Proper welding procedures are necessary in order to avoid damage to the electronic controls and to the bearings. The following steps should be followed in order to weld on a machine or an engine with electronic controls.

Note: If you are welding on a work tool, Caterpillar recommends removing the work tool from the host machine before welding.

1. Turn off the engine.

2. Turn the battery disconnect switch to the OFF position. If there is not a battery disconnect switch, then remove the negative battery cable at the battery.

3. Clamp the ground cable from the welder to the component that will be welded. Place the clamp as close as possible to the weld. Make sure that the electrical path from the ground cable to the component does not go through any bearing. Use this procedure in order to reduce the possibility of damage to the following components:

• Bearings of the drive train

• Hydraulic components

• Electrical components

• Other components of the machine

Protect any wiring harnesses from the debris which is created from welding. Protect any wiring harnesses from the splatter which is created from welding.

Installation Procedure

Use ASTM A572 Grade 42 or 50 steel, or equivalent steel with a minimum of 290 MPa (42000 psi) yield strength.

Note: All areas must be free of rust, clean and free of paint prior to any welding operation.

Note: It is not recommended to use stick welding (SMAW) near the foot casting due to higher carbon content.

Note: Use LB-26 (AWS E7016 or AWS E7018) Electrodes or equivalent electrodes. Basic welding wire ESAB OK tubrod 15.00 with a 1.2 mm (0.05 inch) diameter can also be used. The basic welding wire must be the equivalent to AWS A5.20 E71T-5 with negative polarity. The welding wire must be protected with CO2 or Argon/CO2 80/20 gas.

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Illustration 1	g01943582
(5) Tack weld

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Illustration 2	g01943608
No gap between block and plate

1. Place a tack weld (5) at the center of the block on each of the two longest opposite sides. See Illustration 1.

2. Make sure that there is no gap between the block and the plate. See Illustration 2.

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Illustration 3	g01943624
(1) Weld (2) Weld (3) Weld (4) Weld

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Illustration 4	g01943628
Weld 30 mm (1.18 inch) beyond the edge of the block.

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Illustration 5	g01943629
(6) Flare welds in order to avoid undercut at corners of the block.

3. Start weld (1) 5 mm (0.20 inch) to 10 mm (0.40 inch) away from the tack weld. Refer to Illustration 3 and Illustration 4. The weld should be a 7 mm (0.28 inch) fillet on the block. This tapers to a 3 mm (0.12 inch) flat weld at the corner of the block.

4. Run a continuous pass 30 mm (1.18 inch) past the edge of the block. When possible, flare the weld slightly 5 mm (0.20 inch) to 10 mm (0.40 inch) in order to help avoid undercut at the corners of the block. Refer to Illustration 5.

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Illustration 6	g01943630
Grind the edge of the welds 5 mm (0.20 inch).

5. Grind the end of the weld 5 mm (0.20 inch) flush with the plate in order to avoid a stress riser. Refer to Illustration 6.

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Illustration 7	g01943631
Weld (2)

6. Start weld (2) by overlapping weld (1) by 5 mm (0.20 inch) to 10 mm (0.40 inch). Refer to Illustration 7.

7. Run a continuous 7 mm (0.28 inch) fillet weld along the block. Taper the weld to a 3 mm (0.12 inch) flat weld at the corner of the block.

8. Weld 30 mm (1.18 inch) past the corner of the block. Refer to Illustration 5. When possible, flare the weld slightly 5 mm (0.20 inch) to 10 mm (0.40 inch) in order to help avoid undercut at the corners of the block. Refer to Illustration 5.

   Note: If the design prevents flaring of the weld, extend the weld 30 mm (1.18 inch) past the edge of the block. Keep the weld parallel to the edge of the block.

9. Grind the end of the weld 5 mm (0.20 inch) flush with the plate in order to avoid a stress riser. Refer to Illustration 6.

10. Repeat Steps 3 through 5 for weld (3) .

11. Repeat Steps 6 through 9 for weld (4) .