Procedure for Repairing Cracks in the Rear Track Roller Frame{4151} Caterpillar

Track-Type Tractor:

D10N (S/N: 2YD1-UP; 3SK1-UP)

D10R (S/N: 3KR1-UP; AKT1-UP)

Introduction

This procedure describes the repair process for track roller frames with cracks in tube welds, skirt welds, and castings. Cracks that occur can be repaired by welding and reinforcing in order to extend the life of the track roller frame. Use the parts from 212-3490 Reinforcement Arrangement that are listed in Table 4.

Do not perform any procedure in this special instruction until the information has been read and understood.

After the repair is complete, prepare the machine for service. Refer to the Operation and Maintenance Manual for your machine.

Safety

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Personal injury or death can result from improper assembly procedures. Do not attempt any assembly until you have read and understand the assembly instructions.

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The machine must be on a level, hard surface before a separation of the track is made. Any time a separation of both tracks is made, the machine must have blocks correctly positioned so the machine will not move.

• Permit only one operator on the machine. Keep all other personnel away from the machine.

• Move the machine to a smooth horizontal location. Move away from working machines and personnel. Lower the bulldozer blade to the ground.

• Engage the parking brake.

• Stop the engine.

• Remove the track roller frames. Refer to the Disassembly and Assembly Module for your machine.

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Grease is under high pressure. Grease coming out of the relief valve under pressure can penetrate the body causing injury or death. Do not watch the relief valve to see if grease is escaping. Watch the track or track adjustment cylinder to see if the track is being loosened. Loosen the relief valve only one turn.

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Keep away from the front of the machine when the track is pushed off the final drive. A minimum distance of 7.6 m (25 ft) is needed in front of the track to permit the track to move out onto the floor.

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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.

General Specifications for Welding

The following welding processes are preferred for this repair.

The following welding processes are acceptable for this repair.

Repairing Cracks in the Frame

Repairing Circular Welds

Note: Any repair of a circular weld is extremely dependent on making sure that the entire crack and the entire weld is removed. The crack and the weld must be removed from the top to the bottom and from one end to the other end. The surface for the new weld must be ground clean. The weld must be replaced with a high quality weld. Failure to remove all of the crack and failure to repair all of the crack will almost guarantee the return of the crack.

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Illustration 1	g01063479
(A) Casting (B) 19.3 mm (0.76 inch)

1. Use an air arc to gouge out the visible crack in the tube weld. Gouge out the crack from one skirt plate to the other skirt plate. It is extremely important to remove the entire crack. You may need to gouge the entire depth of the joint in order to make sure that the entire crack is removed. Grind the surface until the surface is smooth. Apply some dye penetrant in order to make sure that the entire crack has been removed.

   Note: The depth of the joint is the same depth for the joint for the pivot shaft casting and the joint for the equalizer bar casting.

2. Remove the slag from the joint. Use a grinder in order to clean the joint for preparation for welding. Use a rotary file at the intersection of the welds.

3. Use a dye penetrant in order to determine if the crack extends under the skirt plates on the inside or the outside of the frame. If the crack exists, perform Step 1 and Step 2 in ""Repairing Cracks Beneath the Skirt Plate" " section below.

4. Reweld the circular weld. Start at the intersection of the skirt plate and the circular weld. Weld one pass to the top of the tube by using a weaving technique. Repeat the process by starting on the opposite side of the frame. Repeat this sequence until the joint is completely welded. Use a grinder to blend in the toes.

Repairing Cracks Beneath the Skirt Plate

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Illustration 2	g01063489
(C) 150 mm (5.9 inch) (D) 150 mm (5.9 inch)

1. You can cut a window in the skirt plate in order to access the lower half of the circular weld after you weld the tube. See Illustration 2.

2. Remove the circular weld by gouging the weld with an air arc. Use a dye penetrant in order to verify that the end of the crack has been reached. If the crack extends beyond reach, perform the steps that are in ""Repairing Cracks That Are Out of Reach" ".

3. Remove the slag from the joint. Use a grinder to clean the joint in preparation for welding. Use a rotary file at the intersection of the welds.

4. Reweld the circular weld.

5. Reweld the skirt plate.

6. Repeat Steps 1 through Step 5 for the opposite side of the track roller frame, if necessary.

Repairing Cracks That Are Out of Reach

1. Remove major bogie "No. 2" and major bogie "No. 3". Also, remove the associated bogie pad assemblies in order to obtain clear access to the welds for the belly pad.

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Illustration 3	g01063531
(E) 75 mm (2.95 inch) (F) 200 mm (7.87 inch) (G) 200 mm (7.87 inch) (H) 196.7 mm (7.74 inch) (J) 150 mm (5.91 inch) (K) 245 mm (9.65 inch) (L) Weld (M) Weld (N) Circular Weld (P) Circular Weld

2. Use an air arc to remove the appropriate weld, either weld (L) or weld (M). These welds are between the belly plate and the steel casting. Also, use an air arc to remove the specified area of the belly plate. Make sure that the four vertical plates that are between the tube and the belly plate are not cut. See Illustration 3.

   Refer to the cutout areas that are shown in Illustration 3. These cutout areas will allow access to circular weld (N) and circular weld (P). At the same time, this will help avoid cutting the vertical plates. In addition, you must be careful not to cut into the tube when you gouge out the belly plate. The belly plate is 18 mm (0.71 inch) thick.

3. Remove the portion of the belly plate. In the area of the split in the belly plate, weld and grind any gouges in the surface of the tube.

4. Use an air arc in order to gouge out the circular welds on the bottom of the tube. Clean the slag from the groove.

5. Reweld the tube by using a weaving technique. In the areas of contact between the tube and the belly plate, grind the weld on the bottom of the tube smooth.

6. Replace the belly plate and tack weld the plate into position. Reweld the belly plate.

Identifying the Frame Configuration

There are three different configurations of track roller frames that are available. See the following illustrations and text in order to determine the configuration of the track roller frame that is on your machine. Refer to the reference number throughout the procedure.

Type 1

Illustration 4	g01063040
156-4203 Rear Frame As (Left Hand)

Illustration 5	g01063055
156-4204 Rear Frame As (Right Hand)

Type 2

Illustration 6	g01063836
147-5353 Frame As (Left Hand)

Illustration 7	g01063058
147-5352 Frame As (Right Hand)

Type 3

Illustration 8	g01063059
172-1643 Rear Frame As (Left Hand)

Illustration 9	g01063060
172-1642 Frame As (Right Hand)

Required Parts

Illustration 10	g01058080

Repair Procedure

Use an Air Arc to Remove the Hook and the Locator for the Pivot Shaft Casting.

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Illustration 11	g01058420
(Q) Vertical Center Line

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Illustration 12	g01058422

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Illustration 13	g01065420

1. Grind the previous area for the hook and grind the previous area for the locator for the pivot shaft casting flush. See Illustration 13 in order to see the locator.

2. Weld up the low spots and grind the area flush.

3. Needle grinding is optional.

   Determining the Vertical Center Line

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Illustration 14	g01058425
(Q) Vertical Center Line (R) Chalk Lines

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Illustration 15	g01058426
(R) Chalk Line (S) Center Punch

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Illustration 16	g01065426
Holes for the Track Adjuster and the Face for the Twister Resister (T) Holes for Track Adjuster (U) Face for Twister Resister

4. On current machines, use holes (T) for the track adjuster in order to determine the center point on the pivot shaft casting.

5. Use faces (U) for the twister resister in order to determine the center line for the rear track roller frame.

6. Use the midpoint on the casting skid plate for the equalizer bar in order to determine the centerline in the front of the rear track roller frame.

7. Apply a mark at the appropriate locations.

8. Create chalk line (R) by using the marks.

   Scribe Inside Edge for the 245-1682 Plate (5) .

9. Measure 110.5 mm (4.35 inch) from each side of vertical center line (Q) .

10. Create at least two marks on each side of vertical center line (Q) .

11. Create chalk line (R) on both sides of vertical center line (Q) .

12. Use center punch (S) to create two permanent marks on both chalk lines (R) .

    Grind All of the Areas.

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Illustration 17	g01058424

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Illustration 18	g01058462

13. Grind all of the painted areas on the frame for locating and welding the plates on the frame.

    Position Plate (5) to the Side of the Frame for the Track Adjuster.

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Illustration 19	g01058463
(R) Chalk Line (V) Level (5) 245-1682 Plate

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Illustration 20	g01058464
(5) 245-1682 Plate

14. Use level (V) to position plate (5). The plate should be perpendicular to the ground. Align the inside edge of plate (5) to chalk line (R) that was created in Step 11.

15. Check for the correct size for the weld joint.

16. Tack weld plate (5) to the frame. Make sure that the plate remains perpendicular to the ground.

    Position 245-1680 Plate (3) and 245-1681 Plate (4) on the Frame.

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Illustration 21	g01058465
(3) 245-1680 Plate (5) 245-1682 Plate

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Illustration 22	g01058467
(4) 245-1681 Plate (5) 245-1682 Plate

17. Align plate (3) so that the angled surface of plate (5) is flush with the angled surface of plate (3) .

18. Tack weld plate (3) in position.

19. Position plate (4) next to plate (5) by using the curved geometry of plate (5) as a guide.

20. Tack weld plate (4) in position.

    Position 245-1683 Plate (6) on the Frame.

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Illustration 23	g01058468
(3) 245-1680 Plate (6) 245-1683 Plate

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Illustration 24	g01058469
(4) 245-1681 Plate (5) 245-1682 Plate (6) 245-1683 Plate

21. Position plate (6) on the frame. Make sure that plate (6) is flush with the angle of plate (3). Make sure that plate (6) lines up with the curved geometry of plate (4) .

22. Use a C-clamp in order to hold plate (5) and (6) to plate (4) .

23. Use a C-clamp in order to hold plate (5) and (6) to plate (3) .

24. Tack weld plate (6) in position.

    Position 245-1679 Plate (2) on the Frame.

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Illustration 25	g01065445
(W) 514.5 mm (20.26 inch) (X) 99.5 mm (3.92 inch) (2) 245-1679 Plate (7) 245-1684 Hook

25. Position hook (7) on plate (2). Use dimension (W) and dimension (X) to locate hook (7) .

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Illustration 26	g01058530
(Y) Angle Iron (2) 245-1679 Plate (5) 245-1682 Plate (6) 245-1683 Plate (7) 245-1684 Hook

26. Weld hook (7) on plate (2) .

27. Weld two sections of angle iron (Y) on plate (2). This will allow you to position plate (2) so the plate is flush with plate (6) and plate (5) .

28. Position plate (2) between plate (5) and plate (6). Tack weld plate (2) in position.

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Illustration 27	g01060580
(Z) Location (AA) Location

29. Weld the side plates and the end plates to the frame from location (Z) to location (AA) on both sides of the frame.

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Illustration 28	g01060150
(3) 245-1680 Plate (5) 245-1682 Plate (6) 245-1683 Plate

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Illustration 29	g01060155
(4) 245-1681 Plate (5) 245-1682 Plate (6) 245-1683 Plate

30. Grind a chamfer on plate (3) and plate (4) in order to enlarge the chamfer. This will help ensure that the completed weld is the correct size.

31. Make sure that there is a 12 mm (0.47 inch) bevel between the plates. Use a 4 inch grinder to enlarge the bevel, if necessary.

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Illustration 30	g01060158
(3) 245-1680 Plate (5) 245-1682 Plate (6) 245-1683 Plate

32. Finish welding the plates with additional weld passes. Use three passes between plate (3) and the track roller frame. Use two passes between plate (3) and plate (5) and plate (6) .

33. Remove the cover on the hole for the track adjuster. This will allow access for welding.

34. Before welding around the hole for the track adjuster, make sure that you protect the hole and the threaded holes.

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Illustration 31	g01060159
(4) 245-1681 Plate

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Illustration 32	g01058536
(4) 245-1681 Plate (6) 245-1683 Plate

35. Start welding on the side of the frame with the track adjuster. Weld around the corner of plate (4) for a distance of one inch. See Illustration 31. Repeat for the other side of the track roller frame that is shown in Illustration 32.

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Illustration 33	g01060161
(4) 245-1681 Plate (5) 245-1682 Plate (6) 245-1683 Plate

36. Apply the second vertical weld pass (final pass) between plate (4), plate (5), and plate (6) .

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Illustration 34	g01060162
(4) 245-1681 Plate (5) 245-1682 Plate

37. Apply a second pass between the plate (5) and the track adjuster. Continue the weld around the corner of plate (4). Repeat for the other side.

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Illustration 35	g01060164
(4) 245-1681 Plate (5) 245-1682 Plate

38. Complete welding plate (4) to the track roller frame with a total of three weld passes.

39. Fill the joint between the edge of the track adjuster surface and plate (5) with three weld passes. Complete the weld with one full fillet weld pass. Grind the welds flush. See Illustration 35.

    Note: A total of nine weld passes are required between plate (4) and the hole for the track adjuster. A total of six to seven weld passes are required between plate (5) and the hole for the track adjuster.

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Illustration 36	g01060163

40. Check and chase the 1/2 inch holes with a tap, as required.

    Weld 245-1682 Plate (5) and 247-5486 Plate (8) .

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Illustration 37	g01060166
(AB) Cover on Hole for Track Adjuster

41. Roll over the track roller frame on the side, as shown. The ears on the equalizer bar should be pointing toward the ground. The outboard side should be pointing upward.

    Position the track roller frame on blocks. Do not position the blocks under the retainer assembly.

42. Reinstall cover (AB) on the holes for the track adjuster.

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Illustration 38	g01060167
(4) 245-1681 Plate (5) 245-1682 Plate

43. Start a root weld pass between the frame and plate (5). Apply a 6 to 8 mm (0.24 to 0.32 inch) fillet weld. Add the final two passes so that the passes overlap the start areas and the stop areas.

    Weld 247-5486 Plate (8) to the track roller frame.

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Illustration 39	g01060168
(8) 247-5486 Plate

44. Position plate (8) for the best location between the following components: existing skirt plate weld, twister resister weld, weld on side plate and wall of the track adjuster. Carry the weld pass around the corners as much as possible. Carry the weld pass for a minimum distance of 25 mm (0.98 inch).

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Illustration 40	g01060329
(8) 247-5486 Plate

45. Apply the weld so that the weld is flush around plate (8) .

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Illustration 41	g01060331

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Illustration 42	g01060332

46. Grind the welds in order to remove any weld splatter or high spots. See Illustration 41 and Illustration 42.

    Weld 245-1683 Plate (6) and 247-5487 Plate (9) .

47. Position the track roller frame so that the ears for the equalizer bar are pointed upward.

    Position the track roller frame on blocks. Do not position the blocks under the machined surface on the pivot shaft casting.

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Illustration 43	g01060333
(4) 245-1681 Plate (6) 245-1683 Plate

48. Start a root weld pass between the frame and plate (6). Apply a 6 to 8 mm (0.24 to 0.32 inch) fillet weld. Add the final two passes so the passes overlap any start areas and stop areas.

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Illustration 44	g01060334
(9) 247-5487 Plate

49. Position plate (9) for the best location between the following components: existing skirt plate weld, twister resister weld, weld on side plate and wall of the track adjuster. Carry the weld pass around the corners as much as possible. Carry the weld pass for a minimum distance of 25 mm (0.98 inch).

50. Apply the Weld so that the weld is flush around plate (9). Grind the welds in order to remove any weld splatter or high spots.