The Cutting Edge has Been Improved on Certain 623H and 623K Wheel Tractor-Scraper {6212} Caterpillar

Wheel Tractor Scraper

623H (S/N: EJD1-UP; DBF1-UP)

623K (S/N: WTB1-UP; WTM1-UP)

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

Reference: Refer to Disassembly and Assembly, KENR8884, "Floor - Remove and Install" for the 623H Machine serial number prefix DBF.

Reference: Refer to Disassembly and Assembly, KENR9489, "Floor - Remove and Install" for the 623H machine serial number prefix EJD.

Reference: Refer to Disassembly and Assembly, UENR3465, "Floor - Remove and Install" for the 623K machine serial number prefix WTB

Reference: Refer to Disassembly and Assembly, UENR4603, "Floor - Remove and Install" for the 623K machine serial number prefix WTM

Reference: Refer to Tool Operating Manual, NEHS0701, "Using 149-0174 Non-Choker Style Fabric Baskets to Install or Remove Bucket or Blade Cutting Edges" for the 623H Machine serial number prefix DBF.

Description Of Change: The contour of the mounting plate and the gusset locations on the floor assembly have changed. This new design improves the wear life of the cutting edge.

Refer to the procedure below for instructions for performing this rework.

Adaptable To: This rework procedure is adaptable to and effective with the serial numbers in the following table:

Safety

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Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manual. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your Caterpillar dealer for replacement manuals. Proper care is your responsibility.

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Personal injury or death can result from improper troubleshooting and repair procedures. The following troubleshooting and repair procedures should only be performed by qualified personnel familiar with this equipment.

Required Tools

Parts Required

Preparation for Rework

Refer to the Tool Operating Manual to prepare to remove the cutting edges.

Refer to the Disassembly and Assembly Manual for your machine to prepare to remove the bowl floor assembly.

1. Place the machine in PARK

2. Stop the engine and chock the wheels.

3. Turn off the electrical disconnect switch.

Rework the Floor Assembly

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Illustration 1	g03884310

1. Remove 4T-2887 Cutting Edge (A) located at each end of the cutting edge. Retain the parts and hardware for reassembly. The approximate weight of one part is 33 kg (75 lb). Retain cutting edges and hardware for reassembly.

   Refer to the Disassembly and Assembly Manual shown above for your Machine.

2. Remove the 4T-6612 Cutting Edge (B). Retain the part and hardware for reassembly. The approximate weight of one part is 99 kg (220 lb).Retain cutting edge and hardware for reassembly.

   Refer to the Disassembly and Assembly Manual shown above for your Machine.

3. Remove the floor assembly of your machine by referring to the Disassembly and Assembly Manual for your machine. Retain all parts and hardware for reassembly.
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   Illustration 2	g03885003
   View of the scraper floor assembly seen from below the machine looking up.

4. Use an air arc to remove two existing 342-4971 Reinforcements (C). Use a grinder to clean and smooth the area. Fill any under cuts in the floor assembly and grind smooth.
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   Illustration 3	g03884308
   View of the 372-6128 Plate right of center and the floor assembly seen from below. Typical to both sides of the stinger. (D) 147.6 mm (5.81 inch)

5. Locate each new reinforcement (1) using dimension (D) and prepare for welding.

6. Tack weld each new reinforcement (1) into place using several 3 mm (0.12 inch) tack welds.

7. Skip weld each reinforcement (1) from (E) to (F) using 10 mm (0.39 inch) skip welds on each side.

8. Skip weld each reinforcement (1) from (F) to (G) using 6 mm (0.24 inch) skip welds on each side.

9. Clean and paint the welded areas.

Rework 372-6128 Plate

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Illustration 4	g03884389
View of the 372-6128 Plate right of center. Seen from above shown with the cutting edges removed.

1. Mark the location of the new radius as shown in the following step.
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   Illustration 5	g03884280
   View of the 372-6128 Plate right of center. Seen from above shown with the cutting edges removed. (H) 632 mm (24.9 inch) (J) 25 ± 5 mm (1.0 ± 0.2 inch) (K) Point to which radius (L) is blended (L) Radius 51 mm (2.0 inch) (M) Point to which radius (L) is blended

2. Draw the radius (L) for the new contour of the 372-6128 Plate using the dimensions shown above.

3. Use an air arc to rough cut the new radius (L) to within 3.2 mm (0.125 inch) of the finish size.

4. Use a grinder to conform the newly formed radius to the finish dimension. Blend the radius to point (K) and point (M).

   Note: The new smooth edge will prevent stress risers from being generated, which would cause cracks over time.

5. Repeat Step 1 through Step 4 on the left end of the center cutting edge.

6. Clean and paint the affected areas.

7. Reassemble the floor assembly onto scraper bowl. Refer to the appropriate Disassembly and Assembly Procedure Use all retained parts and hardware.

8. Reassemble two retained cutting edges (A) and one retained cutting edge (B) using the existing hardware. Refer to the appropriate Disassembly and Assembly Procedure.