Repair Procedure for Cracks on the Paddle Plate of the Rock Bucket on 988G and 988H Wheel Loaders{6102} Caterpillar

Wheel Loader:

988G (S/N: BNH1-UP; 2TW1-UP)

988H (S/N: BXY1-UP)

Introduction

This rework procedure contains the information that is needed to update the paddle plate design for the 265-8231 Rock Bucket As . There are two main sections in this Special Instruction. One section is for reworking buckets in which this is the first time for a failure. Another section is for replacing the paddle plate on buckets that have had repeat failures. This instruction will cover the following:

• Removal of the existing paddle plate and adjacent components.

• Installation of a new paddle plate, adjacent components, and internal gusset.

• Checking the B-pin and C-pin bore dimensions

The steps in this instruction help to protect the hinge plates and provide support to limit warping from heat during the cutting and rewelding processes. Support bars should be welded between the hinge plates to maintain the dimensional relationship. If the hinge width/bores are out of specification after the rework is complete, a machining operation will be required before reinstallation of the bucket.

The list of components provided includes replacement parts that may be required if damage occurs during weld removal. Use caution in order to salvage components and replace only as needed.

Inspect all welds for cracking or damage during the disassembly process. If a weld is damaged, document the weld location, weld size and take a photograph.

ReferenceRefer to Special Instruction, REHS0579 for general welding. Use 1.3 mm (0.051 inch) diameter weld wire for all welds.

Rework Procedure

Rework Procedure for First Time Failures

One-bend plate repair

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Illustration 1	g02310256

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Illustration 2	g02310258
One-Bend Weld (LH Side Shown)

1. Gouge out the weld from point (J) to (K) between parts (6) one-bend plates and part (15) shell. See Section A-A for weld detail. Reweld entire length with 20 mm (0.79 inch) fillet weld.

2. Gouge out the weld across entire length from point (L) to (M) between parts (6) and (5). See Section A-A for weld detail. Reweld entire length with a 14 mm (0.55 inch) fillet weld (completely fill weld shelf).

Table 1

Required Parts
	Current Parts		Replaced by Parts
ID No.	Part No	Qty	Part No	Qty	Description	Change
1	255-6710	1	361-6173	1	Front Bottom Wear Plate	New design part
2	255-6711	1	361-6174	1	Mid Bottom Wear Plate	New design part
3	255-6712	1	361-6175	1	Rear Bottom Wear Plate	New design part
4	236-7753	2	361-6176	2	Side Bottom Wear Plate	New design part
5	255-6696	1	361-6177	1	Paddle Plate	New design part
6a	255-6704 & 255-6705	1	361-6178	1	One Bend Plate RH	New design part
6b	255-6706 & 288-8192	1	361-6179	1	One Bend Plate LH	New design part
7	N/A	N/A	361-6182	2	Gusset	New design part
8	255-6697	2	255-6697	2	Wing Plate	Existing design - Replacement part
9	255-6702	1	255-6702	1	Mid Plate	Existing design - Replacement part
10	255-6708	1	255-6708	1	Heel Plate Left	Existing design - Replacement part
11	255-6709	1	255-6709	1	Heel Plate Center	Existing design - Replacement part
12	255-6707	1	255-6707	1	Heel Plate Right	Existing design - Replacement part
13	255-6689	6	255-6689	6	Wedges	Existing design - Replacement part
14	236-7759	1	236-7759	1	Edge Backup Strip	Existing design - Replacement part
15	Not Replaced - Protect part from damage during rework				Shell	No Change - Reference Only
16	Not Replaced - Protect part from damage during rework				Side Plate As	No Change - Reference Only
17	Not Replaced - Protect part from damage during rework				Hinges	No Change - Reference Only
18	Not Replaced - Protect part from damage during rework				Edge As	No Change - Reference Only
19	Not Replaced - Protect part from damage during rework				Dump Stop As	No Change - Reference Only

Note: The Replaced by Parts column represents (1) set of parts required to update (1) 265-8231 Rock Bucket As . Refer to Illustrations 5 and 6.

Rework Procedure for Repeat Failures

Illustration 3	g02218736
View is with the shell removed 265-8231 Rock Bucket As before rework

Illustration 4	g02218754
View is with the shell removed 265-8231 Rock Bucket As after rework

Illustration 5	g02219035

Illustration 6	g02219053

Bucket Disassembly

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Illustration 7	g02219073

1. Install the support bars before you disassemble the components of the bucket. The support bars should be welded perpendicular and approximately 75 mm (2.95 inch) X 20 mm (0.79 inch) X 1650 mm (64.96 inch).

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Illustration 8	g02219094

2. Insert a 75 mm (2.95 inch) X 75 mm (2.95 inch) X 16 mm (0.63 inch) angle iron or similar material across the center hinge plates. Weld the ends of tie bars to the inside surfaces of the outer hinge plates. Weld the tie bar to the rear curved surface of each inner hinge plate. The length of the tie bar is approximately 675 mm (26.57 inch).

3. Install 2 75 mm (2.95 inch) X 75 mm (2.95 inch) X 16 mm (0.63 inch) angle iron or similar material across the hinge plates. The length of the tie bar is approximately 735 mm (28.94 inch). Weld the tie bars to each hinge plate.

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Illustration 9	g02219139
(15) Shell - bottom surfaces (17) Hinge - inside and outside surfaces

4. Review the locations of the surfaces shown in Illustration 9. Use caution when you cut the parts that are connected to these surfaces. Damage to these surfaces may result in premature failure of the bucket structure. Any damage will need to be weld repaired and ground flush before the new components are installed.

Bucket Position for Paddle Plate Rework

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Illustration 10	g02219181

1. Position the bucket as shown to provide access to the areas that are indicated by the arrows.

Bottom Wear Plate and Plug Weld Removal

1. Remove the bucket from the machine. Confirm B-pin and C-pin dimensions. Use the checking tool.

   Note: Refer to Appendix B.

2. Install the hinge support bars and shell support bars as shown in Illustrations 7 and 8.

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Illustration 11	g02219314

3. Position the bucket so that the paddle plate (5) faces upward as shown in Illustration 10.

4. Use carbon arc to remove the weld from point (A) to point (B). Remove the weld from point (C) to (D) between the wear plate (1) and the paddle plate (5). Remove the weld from five slots that are marked (E) and remove the plate (1) from the bucket.

5. Remove the weld from point (F) around the perimeter of the wear plate (3). Remove part (3) from the bucket

6. Remove the weld from the two slots that are marked (G). No parts will be removed from the bucket following this step. Use caution when you remove the weld in order to prevent damage to the stop dump weldment (19) .

7. Remove the weld from the six slots that are marked (H). No parts will be removed from the bucket following this step.

One Bend Plate Removal

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Illustration 12	g02219413

1. Remove the weld from point (J) to (K) between the one-bend plates (6) and the shell (15). Use caution when you remove the weld to prevent the damage to the shell. Excess weld that remains on the shell will be ground flush before installation of the new part (6). Refer to section A-A in Illustration 12.

2. Remove the weld from point (J) to (L) between plate (8), one bend plate (6), and the paddle plate (5). Damage to the paddle plate (5) and plate (8 ) is acceptable because these plates will be replaced during reassembly.

3. Remove the weld from point (K) to (M) between the paddle plate (5) and the side plate (16). Use caution when you remove the weld to prevent damage to the side plate. Excess weld remaining on the side plate will be ground flush before reassembly.

4. (Optional) Remove the weld from point (L) to (M) between part (6) and part (5). Damage to the paddle plate (5) is acceptable because this plate will be replaced during reassembly. Refer to section A-A for weld detail.

5. Remove parts (6) from the bucket.

6. Complete steps 1 to 5 for both LH and RH sides of the bucket.

Hinge Gusset and Plate Removal

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Illustration 13	g02236018

1. Remove weld from point (N) to point (P) between the gusset (8) and the shell (15). Use caution when you remove the weld to prevent damage to the shell (15). Excess weld remaining will be ground flush before reassembly.

2. Remove the weld from point (N) to point (R) between part (8) and the hinge (17). Use caution when you remove the weld to prevent damage to the hinge (17). Excess weld that remains will be ground flush before reassembly.

3. Remove the weld from point (S) to point (R). Damage to the plate (8) and the paddle plate (5) is acceptable because these parts will be replaced during reassembly.

4. Remove part (8) from the bucket. Complete steps 1 through 3 for both the left-hand side and right-hand side of the bucket.

Heel Plate Removal

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Illustration 14	g02236297

1. Remove the weld from point (T) to point (U) between the heel plate (12) and the paddle plate (5). Repeat similar weld removal for each part (11) and (10) .

2. Remove the weld from point (V) to point (W) between the heel plate (10) and the hinge (17). Repeat similar weld removal from four locations for parts (11) and (12). Use caution when you remove the weld to prevent damage to the hinges (17). Excess weld that remains will be ground flush before reassembly.

3. Remove the weld from point (X) to point (Y) between the heel plate (12) and the hinge (17). Repeat a similar weld removal in four locations for parts (11) and (10). Use caution when you remove the weld to prevent damage to the hinges (17). Excess weld that remains will be ground flush before reassembly.

4. Remove parts (10), (11) and (12) from the bucket.

Mid-plate Removal

1. Remove the weld from point (AA) to point (BB) between the mid plate (9) and the shell (15). Use caution when you remove the weld to prevent damage to the shell (15). Excess weld remaining will be ground flush before reassembly.

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Illustration 15	g02236654

2. Remove the weld from point (AA) to point (CC) and (BB) to point (DD) between the mid plate (9) and the hinges (17). Use caution when you remove the weld to prevent damage to the hinges (17). Excess weld remaining will be ground flush before reassembly.

3. Remove the weld from point (CC) to point (DD) between the mid plate (9) and the paddle plate (5). Damage to the mid plate (9) and the paddle plate (5) is acceptable because these parts will be replaced during reassembly.

4. Remove the mid plate (9) from the bucket.

Paddle Plate Removal

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Illustration 16	g02237635

1. Remove the weld from four locations from point (EE) to point (FF) between the paddle plate (5) and the hinge (17). Use caution when you remove the weld to prevent damage to the hinges (17). Excess weld remaining will be ground flush before reassembly.

2. Remove the weld from point (JJ) to (KK) and (MM) to (LL) between the side plate (16) and the paddle plate (5). Use caution when you remove the weld to prevent damage to the side plate (16). Excess weld that remains will be ground flush before reassembly. Damage to part (5) paddle plate is acceptable because this part will be replaced during reassembly.

3. Remove the weld from point (KK) to point (LL) between the paddle plate (5) and the edge (18). Refer to the detailed section view for weld detail.

4. Remove the weld between part (5) paddle plate and part (17) hinge by cutting through the bottom surface of the paddle plate.

5. Remove the paddle plate (5) from the bucket.

Illustration 17	g02237674

Wedge Removal

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Illustration 18	g02237833

1. Remove the weld from eight locations from point (NN) to point (PP) between the wedge (13) and the shell (15). Use caution when you remove the weld to prevent damage to the shell (15). Excess weld that remains will be ground flush before reassembly.

2. Remove the weld from the four locations from point (RR) to point (SS) between the wedge (13) and the shell (15). Use caution when you remove the weld to prevent damage to the shell (15). Excess weld remaining will be ground flush before reassembly.

3. Remove six wedges (13) from the bucket.

Prepare the Bucket for Component Installation

1. Inspect and clean all the surfaces on the bottom of the bucket. Weld repair and grind smooth any damaged surfaces. Grind smooth any existing weld protrusions.

Illustration 19	g02237879

Bucket Assembly Position

Do not proceed without reviewing first

Illustration 20	g02237983

Position the bucket as shown with the top surface of the shell floor parallel to the ground and facing upwards.

Paddle Plate Modification to Add Eight Slots

Illustration 21	g02238021

Wedge and Gusset Installation

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Illustration 22	g02238115

1. Position the six 255-6689 Plates (13) .

2. Weld a 12 mm (0.47 inch) fillet weld with a 1.5 mm (0.06 inch) penetration from point (NN) to point (PP) between part (13) wedges and part (15) shell. Repeat the weld eight times for similar weld joints on all six wedges.

3. Weld a 12 mm (0.47 inch) fillet weld with a 1.5 mm (0.06 inch) penetration from point (RR) to point (SS) between part (13) wedges and part (15) shell. Repeat the weld a total of four times for similar weld joints on four center wedges.

4. Position the two 361-6182 Gussets (7) .

5. Weld a 10 mm (0.39 inch) fillet weld from point (TT) to point (UU) between part (7) gusset and part (15) shell. Weld on both sides of the part on the inside and outside surfaces. Repeat the welding for both the parts on the left-hand side and the right-hand side.

6. Position the backup strip (14) to contact the rear surface of part (18) cutting edge and the bottom surface of part (15) shell. Tack weld into place.

Paddle Plate Installation

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Illustration 23	g02238594

1. Position and tack weld the (5) 361-6177 Paddle Plate to the bucket. Ensure proper fit of part (6) one bend LH/RH before you begin the final weld. Refer to the section on ""One Bend Plate Installation" ".

2. Weld 25 mm (0.98 inch) V groove weld with a 4 mm (0.16 inch) root gap from (KK) to (LL) between part (5) paddle plate and part (18) edge. Refer to Section J-J of Illustration 23 for the welding detail.

   Note: Preheat the weld area to 177° C (350° F). Weld from inside to the outside. Cool with blankets.

3. Weld an 8 mm (0.31 inch) fillet weld with a 1.5 mm (0.059 inch) weld penetration from (JJ) to (KK) between part (5) paddle plate and the side plate (16). Repeat for both LH/RH sides.

4. Weld a 10 mm (0.39 inch) fillet weld with a 1.5 mm (0.059 inch) weld penetration from (EE) to (FF) between the paddle plate (5) and the hinge (17) in four locations.

5. Weld a 12 mm (0.47 inch) bevel weld in two locations from (GG) to (HH) between the paddle plate (5) and the dump stop assembly (19).

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Illustration 24	g02240453

6. Weld a 10 mm (0.39 inch) fillet weld with a 1.5 mm (0.059 inch) weld penetration from (VV) to (WW) and from (XX) to (YY) between the paddle plate (5) and the gusset (7). Weld along both the inside and the outside edges for each LH/RH gusset.

Mid Plate Installation

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Illustration 25	g02240693

1. Position the 255-6702 Mid Plate (9) and tack weld as shown in Illustration 25.

2. Weld a 12 mm (0.47 inch) fillet weld with a 1.5 mm (0.059 inch) penetration from point (AA) to (BB) between the mid plate (9) and the shell (15) .

3. Weld a 10 mm (0.39 inch) fillet weld with a 1.5 mm (0.059 inch) penetration from point (AA) to (CC) and (BB) to (DD) between the mid plate (9) and the hinge (17). Blend the weld into the existing hinge welds at the corners (AA) and (BB) .

4. Weld a 10 mm (0.39 inch) fillet weld with a 1.5 mm (0.059 inch) penetration from point (CC) to (DD) between the mid plate (9) and the paddle plate (5) .

Heel Plate Installation

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Illustration 26	g02240907

1. Position the 255-6708 Heel Plate (10), 255-6709 Wear Plate (11), and 255-6707 Wear Plate (12) according to Illustration 26 and tack weld each.

2. Weld a 25 mm (0.98 inch) V groove weld from point (T) to (U) between parts (12) heel plate and part (5) paddle plate. Repeat similar weld for each part (11) and (10) .

3. Weld a 12 mm (0.47 inch) bevel from point (V) to (W) between the heel plate (10), paddle plate (5), and the hinge (17). Blend the weld into the existing welds at point (W). Repeat a similar weld four times for parts (11) and (12) .

4. Weld a 10 mm (0.39 inch) fillet weld with 1.5 mm (0.059 inch) penetration from point (X) to (Y) between the heel plate (12) and hinge (17). Blend the weld into the existing weld at point (Y). Repeat a similar weld four times for parts (10) and (11) .

Wing Plate Installation

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Illustration 27	g02241633

1. Position the 255-6697 Wing Plate (8) and tack weld as shown in the illustrations.

2. Weld a 16 mm (0.63 inch) bevel weld from point (N) to (P) between the gusset (8) and the shell (15) .

3. Weld a 10 mm (0.39 inch) fillet weld with a 1.5 mm (0.059 inch) penetration from point (N) to (R) between the wing plate (8) and the hinge (17) .

4. Weld a 10 mm (0.39 inch) fillet weld with a 1.5 mm (0.059 inch) penetration from point (R) to (S) between the wing plate (8) and the paddle plate (5) .

5. Weld a 10 mm (0.39 inch) fillet weld with a 1.5 mm (0.059 inch) penetration from point (AB) to (AC) between the wing plate (8) and the gusset (7) .

6. Complete Steps 4 of ""Wing Plate Installation" " for both LH/RH sides of the bucket.

One Bend Plate Installation

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Illustration 28	g02241853

1. Position the 361-6178 RH and the 361-6179 LH (6) as shown in the Illustration.

2. Weld a 12 mm (0.47 inch) fillet weld over a 10 mm (0.39 inch) bevel weld from point (J) to (K) between the one bend plate (6) and the shell (15). Due to the complex shape of the one bend parts, the bevel weld size will start at a minimum of 10 mm (0.39 inch) at point (K) but increase in size as point (K) approaches point (J). When you apply the bevel weld, be sure to fill the bevel between the one bend plate (6) and the shell (15). Refer to the section view for details.

3. Weld a 12 mm (0.47 inch) fillet weld over a 5 mm (0.19 inch) bevel weld from point (L) to (M) between the one bend plate (6) and the paddle plate (5). Refer to the section view for details.

4. Weld a 12 mm (0.47 inch) bevel weld from point (J) to (L). Fill the entire bevel between the one bend plate (6) and the wing plate (8) with weld.

5. Weld a 12 mm (0.47 inch) fillet weld with a 1.5 mm (0.059 inch) penetration from point (M) to (K). Fill the entire bevel between the one bend plate (6) and the side plate (16) with weld.

6. Complete Steps 1 to 5 under ""One Bend Plate Installation" " for both the LH and RH sides.

Paddle Plate Plug Welding

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Illustration 29	g02245337

1. Weld a 10 mm (0.39 inch) fillet weld with 1.5 mm (0.06 inch) of penetration around the inside perimeter of two slots that are marked (G). This weld is required to connect the internal gussets of the dump stop weldment (19) to the paddle plate (5) .

2. Weld a 10 mm (0.39 inch) fillet weld with 1.5 mm (0.06 inch) of penetration around the inside perimeter of six slots marked (H). This weld is required to connect the wedges (13) to the paddle plate (5) .

3. Weld a 10 mm (0.39 inch) fillet weld with 1.5 mm (0.06 inch) of penetration around the inside perimeter of eight slots marked (Z). This weld is required to connect the paddle plate (5) to the hinges (17) .

Bottom Wear Plate Installation

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Illustration 30	g02245397

1. Position the 361-6173 Wear Plate (1), 361-6174 Wear Plate (2), 361-6175 Wear Plate (3), and the two 361-6176 Wear Plate (4) as shown in Illustration 30. Refer to Illustration 31 for location dimensions.

2. Weld a 12 mm (0.47 inch) fillet weld with 1.5 mm (0.06 inch) penetration around the perimeter of wear plate (2) and wear plate (3). Weld an 8 mm (0.32 inch) fillet weld around the perimeter of part (4) for both the LH/RH sides. Refer to the locations marked (F) .

3. Weld a 10 mm (0.39 inch) fillet weld with 1.5 mm (0.06 inch) penetration from point (A) to point (B) and point (C) to (D) between the wear plate (1) and paddle plate (5) .

4. Weld a 10 mm (0.39 inch) fillet weld with a 1.5 mm (0.06 inch) penetration around the inside perimeter of the six slots marked (E) .

Support Bar Removal

1. Remove the support bars that were installed in the Bucket Disassembly section.

2. Recheck the pin dimensions for (B) and (C) with the checking tool that is shown in appendix B.

3. If bores are out of line, weld up bores and line the bore to 167 ± 0.08 mm (6.57 ± 0.003 inch) for the pin B and 120 ± 0.08 mm (4.72 ± 0.003 inch) for the pin C.

Bottom Wear Plate Installation (Location Dimensions)

Illustration 31	g02245633

Appendix A Component Shipping Dimensions

Table 2

Part No	Qty	Part Description	Weight (kg ea)	Weight (kg total)	Shipping Dimensions (mm ea)
361-6173	1	Front Bottom Wear Plate	73.4	73.4	2453 X 430 X 12
361-6174	1	Mid Bottom Wear Plate	35.4	35.4	1812 X 170 X 16
361-6175	1	Rear Bottom Wear Plate	43.1	43.1	1400 X 240 X 20
361-6176	2	Side Bottom Wear Plate	10.0	20.0	2453 X 430 X 10
361-6177	1	Paddle Plate	441.0	441.0	3796 X 1025 X 25
361-6178	1	One Bend Plate RH	11.6	11.6	1318 X 771 X 240
361-6179	1	One Bend Plate LH	11.6	11.6	1318 X 771 X 240
361-6182	2	Gusset	7.7	15.5	440 X 210 X 25
255-6697	2	Wing Plate	7.7	15.4	420 X 230 X 16
255-6702	1	Mid Plate	9.0	9.0	258 X 271 X 44
255-6708	1	Heel Plate Left	14.4	14.4	230 X 215 X 25
255-6709	1	Heel Plate Center	26.1	26.1	530 X 347 X 25
255-6707	1	Heel Plate Right	14.4	14.4	230 X 215 X 25
255-6689	6	Wedges	8.1	48.5	565 X 70 X 40
236-7759	1	Edge Backup Strip	6.1	6.1	20 X 10 X 3800

Appendix B Hinge Bore Checking Tool (B-pin and C-pin Dimensions)

Illustration 32	g02246346