Modification to Body Avoids Deforming of the Base Plate.{6203, 6208, 6229, 7050} Caterpillar

Articulated Truck:

D400E Series II (S/N: APF1-UP)

Introduction

This Special Instruction contains information on identifying deformation of the plates of the ejector rollers. The Special Instruction outlines rework that is suggested in order to resolve the problem. The information in this Special Instruction can be applied to the listed machines in order to prevent the possible deformation.

Before performing the rework that is outlined in this Special Instruction, ensure that you understand the information that is contained in the Special Instruction.

References

Reference: Parts Manual, SEBP3025, "D400E Series II Ejector Truck".

Deformation of the Plates for the Ejector Rollers

Illustration 1	g01046384
Typical Example

In some cases, the plates of the ejector rollers deform under the weight of the ejector blade. Illustration 1 shows typical signs of such deformation.

Suggested Rework of the Machine

Illustration 2	g01046386

In order to avoid deformation of the plates for the ejector rollers, weld supports to the outside of both channels under the base plate for the ejector roller. Refer to Illustration 2 for an example of a suitable installation of a support. Repeat the installation for the other channel.

For details of the support plate, refer to ""Details of Support Plate" ". For details on welding the support plates to the machine, refer to ""Welding Details" ".

Weld 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: OHSA Safety and Health Standards, 29 CFR 1910, available from U.S. Dept. of Labor, Washington D.C. 20210.

Welders must be qualified for fillet welding and groove welding. The welder must be qualified in different welding angles. The angles are vertical, horizontal, etc. The welders should be qualified in the use of the welding processes that follow: Shielded Metal Arc Welding (SMAW), Flux Cored Arc Welding (FCAW) and Gas Metal Arc Welding (GMAW). Refer to ISO 9606 or "American National Standards Institiute (ANSI)/American Welding Society (AWS) Specification D1.1, or Specification D14.3" for information that regards the qualifications for the processes that follow: SMAW process, FCAW process and GMAW process. The welders must have used the process at some time within the last six months. The welders must complete the process of certification if the welders have not used the welding processes for six 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. Connect the ground cable for the welder directly to the actual machine component that will be welded. Place the clamp for the ground cable as close as possible to the welding area. This will reduce the chance of damage from welding current to the components that follow: bearings, hydraulic components and electrical components.

   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. Do NOT use hoses as a ground point for the welder. Do NOT use the ground pole on the batteries as a ground point for the welder.

4. Protect the wiring harnesses from the weld splatter.

Prepare the Area for Welding

Clean the area that will be welded. Make sure that the substances that follow are removed from the area that will be welded.

• Oil

• Grease

• Paint

• Dirt

If the temperature of the base metal is below 0 °C (32 °F), heat the base metal to a temperature of at least 21 °C (70 °F). Maintain the temperature of the base metal at 21 °C (70 °F) during the welding process.

Note: Heat distortion of the base metal is possible when you weld. Avoid excessive heating of the base metal. A maximum interpass temperature of 260 °C (500 °F) should be observed.

Attach the welding ground cable directly to the base metal. Protect machined surfaces from sparks. Protect the machined surfaces from the weld splatter.

Weld Specifications

Low Hydrogen Electrodes for the SMAW Process

The tables that follow list the mechanical properties of welds that are deposited by low hydrogen electrodes.

Low hydrogen electrodes must be stored in an electrode oven at 120 °C (250 °F). If low hydrogen electrodes get damp, scrap the low hydrogen electrodes or recondition the low hydrogen electrodes to the manufacturer's specifications.

The table that follows shows setting for the welding current for the electrode diameter.

Use a polarity setting of DC reverse polarity. Remove the slag after each pass of the welding electrode. The width of the weld should not exceed two times the electrode diameter.

Flux Cored Welding Electrode for the FCAW Process

The table that follows lists the mechanical properties of welds that are deposited by the flux cored welding electrode.

The table that follows shows setting for the welding current for the flux cored welding electrode that has a diameter of 1.3 mm (.052 inch).

Note: The settings for the welding current can vary due to the position of the weld. Also, the settings for the welding current can vary with the manufacturer of the welding electrode.

Use a polarity setting of DC reverse polarity. Remove the slag after each pass of the welding electrode. 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 in order to reduce the possibility of evolving gas that is trapped in the weld. The volume of the fillet weld should not exceed 8.0 mm (.315 inch).

Arc Welding Electrodes for the GMAW Process

The table that follows lists the mechanical properties of welds that are deposited by the GMAW Process.

The welding parameters will vary with the position of the weld and with different electrode manufacturers.

Weld Inspection

The weld should not have any of the conditions that follow:

• Cracks

• Porosity

• Undercut

• Incomplete Fusion

In order to verify the quality of the weld, refer to"American National Standards Institiute (ANSI)/American Welding Society (AWS) Specification D14.3" and ISO 6520.

Details of Support Plate

Fabricate the following components from either ASTM A572 grade 50 structural steel or ASTM A656 grade 50 structural steel.

Manufacture two support plates per machine.

Illustration 3	g01059276

Fabricate two support plates from 15 mm (0.6 inch) thick structural steel. Refer to Illustration 3 and Table 7.

Welding Details

When you install the fabricated components to your machine, please note that you must tailor the fit of the fabricated components in order to conform to any deformation of the body that may have occurred because of use of the machine.

Illustration 4	g01059275

Refer to Illustration 4 and Table 8 for information on welding the support plates to the machine. Refer to ""Weld Specifications and Qualifications" ".