Installation and Removal Of The Mechanically Attached Wear Plate System Caterpillar

Caterpillar Products: All

Introduction

This Special Instruction contains the procedures and the information for the installation and removal of the Mechanically Attached Wear Plate System.

The Mechanically Attached Wear Plate System is available in four sizes. The system has a range of thickness from 35 mm (1.38 inch) to 100 mm (3.94 inch). The Mechanically Attached Wear Plate System provides a hammerless means of installation and of removal of wear plates. The system is intended to protect the areas that were previously unprotected or the areas that were protected by weld-on wear plates or by bolt-on wear plates. The Mechanically Attached Wear Plate System is available for a large variety of applications on Caterpillar and on non-Caterpillar equipment.

The wear plates are available for standard applications and for heavy-duty applications. The wear plates are made from Caterpillar formulated DH-2 steel. To obtain optimum strength and optimum wear life, a through hardened steel is used. The base plate is made from slightly softer steel but the steel is a tough weldable steel in order to withstand the high forces. The base plate is not subject to wear under normal conditions since the base plate is entirely covered by the wear plate. The patented compression retainer is investment cast from a spring steel material. The retainer acts as a spacer when the retainer is located in the holding position. As a system, the Mechanically Attached Wear Plate System will accept loads from any direction. The Mechanically Attached Wear Plate System does not require specific orientation when the wear plates are compared with competitive wear plates. The only requirement for the system is approximately 50 mm (2 inch) of space from adjacent objects in order to facilitate replacement.

The Mechanically Attached Wear Plate System can be installed on most flat surfaces or on moderately curved surfaces. Refer to ""Parts List" " for the limitations of the radius. The following list is the possible applications for protection by use of wear plates: bucket bottoms and bucket sides, bulldozer push arms, excavator bucket ski runners, excavator bucket sides, truck body duck tails, Tiger bulldozer blades and crusher hoppers. The system has the following features: long life, ability to customize the protection and ease of use. These features help the system to become a popular alternative to bolt-on wear plates or to weld-on wear plates.

The wear plate has recessed holes (blind holes) that are cast into each corner. The holes serve as a wear indicator that makes inspection quick and easy. When the holes become exposed in one or more of the corners, the wear plate must be changed. If the wear plate is allowed to wear beyond the wear indicator, damage to the base plate may occur.

Read the entire special instruction. Understand the information before you perform any of the procedures. Understand the information before you order any of the parts.

The suggested tools and equipment should be readily available. If the tools are not available, assembly will be more difficult and more time will be necessary to complete the assembly.

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Personal injury can result from not following the specified procedure. To avoid personal injury, follow the procedure as specified.

Reference: Special Instruction, REHS0260, "Removal and Installation of 138-0006 Retainer and 138-0007 Retainer".

Features and Benefits

Mechanical Hammerless Installation - The Mechanically Attached Wear Plate System consists of a through hardened DH-2 wear plate. The wear plate slides onto a permanent weld-on base plate and the wear plate is held in place with a new retainer. Worn wear plates can be quickly replaced by using a common prybar without hammering or without welding. This makes removal and installation quick and easy.

Reduced Downtime and Maintenance - The wear plate can usually be changed in two minutes or less. Because the wear plate can be changed quickly, downtime is reduced and the time for maintenance is reduced when the wear plates are compared to weld-on wear plates or bolt-on wear plates.

Long Wear Life - The retainer is positioned low in the base plate. This allows a greater percentage of the wear plate to be worn away before replacement. Competitive wear plates position the retainer higher in the wear plate. Therefore, this reduces the amount of wear material that is available. This is a more efficient use of the total material that lengthens the replacement intervals. This also provides less additional bucket weight for comparable protection.

Flexible Application - The weld-on base plate can be welded on most flat surfaces or on moderately curved surfaces. Refer to the notes that are above each of the Tables for information on the radius that requires wear protection. The system is designed to take loads from any direction so the orientation of the wear plate to the direction of the load is not important. The Mechanically Attached Wear Plate System can easily be used to customize a wide variety of wearing surfaces.

Weld Information

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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.

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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.

Read the instructions from the manufacturer and understand the instructions from the manufacturer. 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 in the welding helmet. Use proper eye protection, ear protection, and body protection while you are preparing the surfaces and while you are welding on the surfaces. Use a welding helmet with a filter plate that is at least Shade-11.

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 six months. Welding qualifications must be documented and welding qualifications must be current. The alternate process for this repair could be Flux Cored Arc Welding (FCAW).

Preheat the mounting area for the wear plate bases prior to welding. Refer to the table below preheating specifications. The preheat should extend 50 - 75 mm (2 - 3 inch) beyond the weld. The wear plate bases should be preheated to the same temperature as these areas.

The proper stick welding electrode for Shielded Metal Arc Welding (SMAW) is E7018 American National Standards Institute (ANSI)/American Welding Society (AWS) A5.1. The finished weld will have the following minimum mechanical properties:

• 500 MPa (72519 psi) Tensile Strength

• 420 MPa (60916 psi) Yield Strength

• 22 percent elongation in 50 mm (2 inch)

• 27 N·m (20 lb ft) Notch Thickness at -18 °C (-0.0 °F)

The E7018 electrodes must be stored in a electrode oven at 121 °C (250 °F). Scrap the E7018 electrodes or recondition the E7018 electrodes if the E7018 electrodes get damp. Recondition the E7018 electrodes to the manufacturer's recommendations. The following table is the electrode's current settings in relation to the electrode's diameters:

Set the polarity to direct electrode positive (reverse polarity). Use the direct current. Remove the slag after every pass. The width of the weld should not exceed two times the electrode diameter.

Use the Flux Cored Arc Welding (FCAW) with a E71T-1 (ANSI/A5.20) welding electrode and with the manufacturer's shielding gases that are specified for inside welding. The weld that is deposited by the electrodes will have the following minimum mechanical properties:

• 500 MPa (72519 psi) Tensile Strength

• 420 MPa (60916 psi) Yield Strength

• 22 percent elongation in 50 mm (2 inch)

• 27 N·m (20 lb ft) Notch Thickness at -18 °C (-0.0 °F)

Note: This type of electrode has limitations if the electrode is used to carry larger weld pass volumes in the flat position. The slag system of the electrode has fast freezing characteristics. There is a chance of trapping evolving gases in the weld melt. The weld pass volume should be controlled with caution.

Welding parameters will vary due to the position and due to the manufacturer of the welding electrode. A 1.30 mm (0.052 inch) electrode should have the following properties:

Set the polarity to direct electrode positive (reverse polarity). Use the direct current. Remove the slag after every pass. The width of the weld should not exceed 8 mm (0.31 inch) of the volume of the fillet.

Clean the area of oil, of grease, of paint, and of dirt. Attach the welding ground cable to the area. Protect all of the machined surfaces from the sparks or from the splatter that is produced by welding, by chipping, and/or by grinding.

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

Parts List

Note: The retainers CAN NOT be reused if the retainers are out of flatness by more than 2 mm (0.08 inch) or if there is any plastic deformation.

20 Series of the Mechanically Attached Wear Plate System for 980 Wheel Loaders, for 988 Wheel Loaders, for 345B Excavators, and for Other Similarly Sized Machines

Note: The minimum radius for the 20 Series of the Mechanically Attached Wear Plate System is 200 mm (7.9 inch).

Note: 138-0006 Retainer CAN NOT be reused if the retainers measure less than 87 mm (3.43 inch).

30 Series of the Mechanically Attached Wear Plate System for 990 Wheel Loaders, for 992 Wheel Loaders, for 375 Excavators, for 5080 Excavators, and for Other Similarly Sized Machines

Note: The minimum radius for the 30 Series of the Mechanically Attached Wear Plate System is 400 mm (15.8 inch).

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

40 Series of the Mechanically Attached Wear Plate System for 5130 Excavators, for 5130B Excavators, and for Other Similarly Sized Machines

Note: The minimum radius for the 40 Series of the Mechanically Attached Wear Plate System is 800 mm (31.5 inch).

Note: 138-0007 Retainer CAN NOT be reused if the retainer measures less than 97 mm (3.82 inch).

50 Series of the Mechanically Attached Wear Plate System for the 994 Wheel Loaders, for the 5230 Excavators, and for Other Similarly Sized Machines

Note: The minimum radius for the 50 Series of the Mechanically Attached Wear Plate System is 1200 mm (47.2 inch).

Note: 138-0007 Retainer CAN NOT be reused if the retainer measures less than 97 mm (3.82 inch).

Installation Instructions

1. Locate the area that will be protected. Clean the area free of dirt, of paint, and of debris. Be sure to leave a minimum of 50.8 mm (2 inch) clearance from adjacent objects for removal and for installation of the wear plate.

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Illustration 1	g00830781
Typical base plate for the Mechanically Attached Wear Plate System

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Illustration 2	g00830782
Bottom view of the base plate for the 50 series Note the J-Groove at locations "B" and "C".

2. Position the base plate in the desired location. Weld the base plate in position at the locations "A" and "B". Location "C" is used only for the base plate of the 50 Series. Make one pass at a time in each location in order to avoid excess heat buildup. The base plate will require several passes at each location in order to ensure that the proper strength is achieved. Use Table 8 in order to determine the sizes of the fillet welds and the J-groove welds and the number of passes for the base plate of each series.

   Note: The gaps between the base material and the base plate should be minimized. If necessary, tack welds can be used.

   Note: Do not weld along the sides of the base plate. The wear plate will slide over the base plate and any welds in these locations may interfere with the installation of the wear plate.

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   Table 8

   The Sizes of Welds and The Number of Required Passes
   Series of Base Plate	Fillet And/Or J-Groove Weld	Passes	Location of Welds
   20 Series	15 mm (0.6 inch)	3	A & B
   30 Series	15 mm (0.6 inch)	3	A & B
   40 Series	18 mm (0.7 inch)	6	A & B
   50 Series	20 mm (0.8 inch)	8	A, B, & C

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Illustration 3	g00830783
Installation of the wear plate on the base plate

3. Position the wear plate over the base plate. Slide the wear plate onto the base plate.

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Illustration 4	g00830784
Bottom view of the wear plate that is assembled on the base plate

Note: The dovetail on the wear plate seats in the groove in the base plate.

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Illustration 5	g00830786
The bottom view of the assembled wear plate and base plate that is showing the rest point of the retainer.

4. Install one end of the retainer under the point.

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Illustration 6	g00830787
Top view of the assembled base plate, the wear plate, and the retainer showing the position to install the prybar.

5. Insert a small prybar between the base plate and the wear plate. The point of the prybar should be 8 mm (0.31 inch). The curved portion of the prybar should face toward the retainer. Push the prybar toward the retainer. The retainer will snap into position. After the retainer compresses and the retainer goes over center, the retainer will snap into position and the retainer will expand.