Installation of Direct Conversion Center Tread Idlers {4159} Caterpillar

Track-Type Tractor

D6H (S/N: 4RC1-UP; 3ZF1-UP; 5HF1-UP; 6CF1-UP; 4LG1-4067; 1FJ1-UP; 6JJ1-UP)

D6H LGP (S/N: 6FC1-UP; 8FC4092-UP; 8YC1-UP; 3YG1-UP)

D6H STD (S/N: 8KB1-UP; 4RC1-UP; 7PC1-UP; 3ZF1-UP; 5HF1-UP; 6CF1-UP; 4LG1-4067; 1FJ1-UP)

D6H Series II (S/N: 4LG4068-UP; 8KK1-UP; 9LK1-UP)

D6H Series II LGP (S/N: 1KD1-UP; 2TG1-UP; 4GG1-UP)

D6H Series II STD (S/N: 2KD1-UP; 3ED1-UP; 4YF1-UP; 4LG4068-UP)

D6H Series II XL (S/N: 8ZJ1-UP; 9KJ1-UP; 8SK1-UP; 9RK1-UP)

D6R (S/N: 8TM1-UP; 7GR1-UP; 1RW1-UP)

D6R LGP (S/N: 4HN1-UP; 8LN1-UP; 9PN1-UP; 4TR1-UP; 7AR1-UP)

D6R STD (S/N: 2HM1-UP; 4FM1-UP; 2YN1-UP; 3ZN1-UP; 5PR1-UP; 6FR1-UP; 9ZS1-UP)

D6R XL (S/N: 9BM1-UP; 4MN1-UP; 5LN1-UP; 4JR1-UP; 4WR1-UP; 5RR1-UP; 6MR1-UP)

D6R XW (S/N: DMP1-UP)

D6R Series II (S/N: BNC1-UP; DAE1-UP; BPM1-UP; FDT1-UP)

D6R Series II LGP (S/N: AFD1-UP; ADE1-UP; ACJ1-UP; BPP1-UP; BPZ1-UP)

D6R Series II STD (S/N: BLE1-UP; BRJ1-UP; BMK1-UP; BNL1-UP; AEM1-UP; AFM1-UP; BLT1-UP; BMY1-UP)

D6R Series II XL (S/N: CAD1-UP; BMJ1-UP; AGM1-UP; BPS1-UP; AAX1-UP; BRZ1-UP)

D6R Series II XW (S/N: BRE1-UP; AEP1-UP)

D6R Series III (S/N: DMK1-UP; JEK1-UP; JDL1-UP; MRT1-UP)

D6R Series III LGP (S/N: WCB1-UP; WRG1-UP; DLM1-UP; LGP1-UP)

D6R Series III STD (S/N: TBC1-UP; HCD1-UP; GMT1-UP)

D6R Series III XL (S/N: GJB1-UP; RFC1-UP; HKE1-UP; EXL1-UP; LFM1-UP)

D6R Series III XW (S/N: HDC1-UP; MTJ1-UP; DPS1-UP; EXW1-UP)

Introduction

This Special Instruction provides the procedures for installing direct conversion center tread idlers on the undercarriages of the listed models of Caterpillar machines. The procedure requires separation of the track and removal of the idlers. The procedure requires some grinding and welding on the track roller frames.

To use center tread idlers on a machine, the machine must be equipped with the rotating bushing track or the SystemOne track.

The undercarriage arrangement with center tread idlers is different from a conventional undercarriage. The track links ride on the flanges of the idler in a conventional undercarriage. Scalloping of the center of the track links occurs between the track links and the idler. In an undercarriage arrangement with center tread idlers, a rotating bushing rides on a center tread idler with a larger diameter. The center tread idler eliminates contact between the track links and the idler. The rail surface of the track link remains relatively flat throughout the track wear life. Also, the rotating bushing causes less wear on the idler.

These procedures are separated according to the type of undercarriage on your machine. Follow the first procedure if your machine has a Standard undercarriage (STD undercarriage). Follow the second procedure if your machine has an Extra Long undercarriage (XL undercarriage), an Extra Wide undercarriage (XW undercarriage), or an Intermediate Gauge undercarriage (IG undercarriage). The IG undercarriage was a custom arrangement that did not have a separate serial number. The third procedure is for machines with a Low Ground Pressure undercarriage (LGP undercarriage).

Do not perform any procedure in this Special Instruction or order any parts until you read the information and you understand the information.

Reference: Refer to the Parts Manual, Disassembly and Assembly, and Operation and Maintenance Manual for your machine.

Safety

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Do not attempt to disassemble or assemble this machine until you read and understand the disassembly and assembly instructions. Improper disassembly and assembly procedures could result in injury or death.

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Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system. Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

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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.

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Personal injury or death can result from fumes, gases and ultraviolet rays from the weld arc. Welding can cause fumes, burn skin and produce ultraviolet rays. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing area. Wear eye, ear and body protection before working. 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 cause death. Read and understand the manufacturer's instructions and your employer's safety practices. Do not touch live electrical parts. See "American National Standard Z49.1, Safety in Welding and Cutting" published by the American Welding Society. American Welding Society 2501 N.W. 7th Street Miami, Florida 33125 See "OSHA Safety and Health Standards, 29 CFR 1910", available from U.S. Department of Labor. U.S. Department of Labor Washington, D.C. 20210

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Personal injury or death can result from improper lifting or blocking. When a hoist or jack is used to lift any part or component, stand clear of the area. Be sure the hoist or jack has the correct capacity to lift a component. Install blocks or stands before performance of any work under a heavy component. Approximate weights of the components are shown. Clean all surfaces where parts are to be installed.

Note: Do not use lifting tongs to lift the center tread idler. Use two nylon straps to lift the center tread idler. The weight of the idler is 145 kg (320 lb).

STD Undercarriage Arrangements

Necessary Parts

Illustration 1	g01293621
The Lower Scraper is installed.

Reference: Refer to Special Instruction, REHS2937, "Installation Of Lower Scrapers On Center Tread Idlers" for the installation of the lower scraper.

Note: STD undercarriage arrangements use the existing cap assemblies and the existing bearing blocks. If the cap assemblies and bearing blocks need replacement, 165-6946 Bearing Blocks and 152-3421 Cap Assemblies may be ordered. The existing adjustment shims for the front idler are not used.

Note: New longer bolts and new thicker washers are now used for mounting the cap assemblies and bearing blocks. Two sets of bolts and washers are included in the arrangement. For D6H, use English bolts and washers. For D6R, D6R Series II, and D6R Series III use Metric bolts and washers. Be careful to select the proper mounting hardware to avoid damage from cross threaded fasteners. Discard the unused set of hardware.

Preparation of the Undercarriage

1. Separate the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Separate" in the Service Manual for the proper procedure.

2. Remove the front and rear idlers from both sides of the machine. Remove the bearing blocks and shims. Refer to Disassembly and Assembly, "Idlers - Remove" in the Service Manual for the proper procedure.

3. Use a wire brush or a wire wheel to clean the bearing blocks, the caps, the dowels, and the mounting areas on the track roller frame.

Adjustment of the Dowel Pins

Perform the following procedure on all eight dowel pins.

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Illustration 2	g01003770

4. Inspect the dowel pins on the front and rear track roller frames. The dowel pins should be smooth with no visible wear or shear steps. The dowel pins should fit tightly in the track roller frame.

5. Measure height (A) of the dowel pins. Adjust the height, if necessary. The correct height for the dowel pins in both the front and the rear track roller frame is 28 ± 1 mm (1.10 ± 0.04 inch).

   Note: The dowel pins may be difficult to pull out. Only on the front track roller frame, you may drive the dowel pin completely into the frame. Then, insert a new 7T-5886 Dowel Pin.

Welding the Permanent Shims

Two different mounting shims for the idler are provided in the arrangement. The shims arevery similar in appearance, but the thickness differs. Shim (2) is 6 mm (0.24 inch) thick. Shim (3) is 10 mm (0.39 inch) thick. Both shims are installed in the mounting of the idlers. However, the thin shim (2) is welded to the front track roller frame. Shim (2) is also used as the adjustment shim on the rear track roller frame. The thick shim (3) is welded to the rear track roller frame. Shim (3) is also used as the adjustment shim for the front track roller frame. The adjustable shims may be removed as the undercarriage wears to adjust the height of the idler.

The shims must not be mixed during this procedure. Locate four thick shims (3) and put the shims aside for later use. Also, locate four thin shims (2) and put the shims aside for later use.

Perform the following procedure for all eight mounting blocks.

6. Use a wire brush or a wire wheel to clean the mounting surface for the bearing block on the track roller frame.
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   Illustration 3	g01291828

7. Install shim (2 or 3), bearing block (11), and cap assembly (12) with two bolts (4) and two washers (5). Do not install the idler now.

   Note: Be careful to use the correct bolts and washers. Tractors that are series H use English fasteners. Tractors that are series R use Metric fasteners.

   Note: Some block and cap assemblies have a gap (B) of 3 mm (0.12 inch) on one side only. See Illustration 3. If there is a gap on one side of the block and cap assembly, install the existing 5P-8248 Mounting Washer (D6H) or 8T-3282 Mounting Washer (D6R) in the gap. Install mounting bolt (4) through this washer. This will ensure that the permanent shim is tight against the frame when the idler assembly is not installed. Early block assemblies do not need a washer because the large one side gap does not exist.

8. Align shim (2) or shim (3) so that the shim is parallel with the rails of the track roller frame. Tighten bolts (4) so that the shim is held tightly to the track roller frame. There is no need to torque the bolts now.

9. Remove the paint from the welding area around the perimeter of the permanent shim.

10. Weld three butt welds on both the outside edge and the inside edge of the shim. Each weld should be 4 mm (0.16 inch) wide by 12 mm (0.47 inch) long . The welds are indicated in Illustration 3.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

11. Remove bolts (4), washers (5), and cap assembly (12). If you placed a washer in gap (B), discard the washer. Do not remove bearing block (11).

12. Repeat Steps 6 through 11 for all eight mounting blocks.

Installation of the Base Plates

Perform the following procedure for all four idlers.

Note: Step 13 through Step 19 is a test procedure. The test procedure is performed to identify proper clearance between the center tread idlers and the track roller frame. The test procedure is also performed to locate the base plates with the center tread idlers.

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Illustration 4	g00989272

13. Install idler (1) on bearing blocks (11). Only the permanent shims should be in place now.

14. Install cap assemblies (12). Align the holes in the idler shaft with the spring pins in the cap assemblies.

15. Install two bolts (4) and two washers (5) in each cap assembly.

16. Tighten the four bolts so the two bearing blocks are snug to the track roller frame. The bolts do not need torqued now.

17. Rotate the idler. The idler should rotate freely with no interference. On the top plate of the rear track roller frame, there may be a slight interference between the idler and the track roller frame. If interference exists, remove the idler and grind a clearance in this area. Install the idler. If the idler rotates freely, proceed to the next step.
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    Illustration 5	g00989276

18. Locate base plate (6) on the track roller frame. Refer to Illustration 5. Leave a clearance (C) of 6 mm (0.24 inch) between the inside edge of the base plate and the idler tread. The slot in the base plate should be centered and parallel with the idler tread.

19. Rotate the idler. There should be no interference between the base plate and the idler.

20. Remove the paint from the welding area.

21. Tack weld the base plate in place.

22. Remove the idler, the cap assemblies, and the bearing blocks.

23. Skip weld the base plate to the track roller frame with 8 mm (0.3 inch) by 50 mm (2 inch) long fillet welds with 1.5 mm (0.06 inch) penetration around the entire outside edge of the plate. Refer to Illustration 5.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

24. Repeat Steps 13 through 23 for all four idlers.

Installation of Adjustment Shims, Bearing Blocks, and Idlers

Perform the following procedure for all four idlers.

25. Apply 4C-5593 Anti-Seize Compound to the dowel pin holes in the bearing blocks.
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    Illustration 6	g01291850

26. Install one shim (3) or one shim (2) over each dowel pin.

27. Install two bearing blocks (11) on the dowel pins.

28. Install idler (1).

29. Install cap assemblies (12). Align the holes in the idler shaft with the spring pins in the cap assemblies.

30. Apply 4C-5593 Anti-Seize Compound to the threads on four bolts (4).

31. Install four bolts (4) and four washers (5) in cap assemblies (12).
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    Illustration 7	g01004229

    Note: For cap assemblies with a gap (B) on one side, tighten the bolt on the abutment side (D) first. "TIGHTEN FIRST" is stamped on the abutment side (D) of the cap assembly. See Illustration 7. For cap assemblies that do not have a gap on one side, there is no marking. The bolts are tightened by alternating evenly. A small gap results on both sides of the cap assembly.

32. Tighten bolts (4) to the specified torque. See Table 3.
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    Table 3

    Torque Specifications
    Model	Bolt Size	Torque
    D6H STD	3/4 inch	475 ± 60 N·m (350 ± 45 lb ft)
    D6R STD	20 mm	570 ± 80 N·m (420 ± 60 lb ft)

33. Repeat Steps 25 through 32 for all four idlers.

Installation of the Scrapers

Perform this procedure for all four idlers.

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Illustration 8	g01004230

34. Install two side scrapers (7) and one scraper (8) with eight bolts (9) and eight washers (10). Leave a minimum of clearance between the scrapers and the idler.

35. Rotate the idler by one full revolution. The idler should rotate freely. If the idler does not rotate freely, adjust the scrapers to eliminate the interference.

36. Tighten bolts (9).

37. Repeat Steps 34 through 36 for all four idlers.

Preparation for Service

38. Connect the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Connect" in the Service Manual for the proper procedure.

39. Adjust the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Adjust" in the Service Manual for the proper procedure.

40. Prepare the machine for operation. Refer to the Operation and Maintenance Manual for instructions.

XL, XW, and IG Undercarriage Arrangements

Steps For XL, XW, and IG Arrangements on D6H, D6H Series II, D6R, and D6R Series II Track-Type Tractor

Necessary Parts

Illustration 9	g01293621
The Lower Scraper is installed.

Reference: Refer to Special Instruction, REHS2937, "Installation Of Lower Scrapers On Center Tread Idlers" for the installation of the lower scraper.

Note: XL, XW, and IG undercarriage arrangements use the existing cap assemblies and the existing bearing blocks. If the cap assemblies and bearing blocks need replacement, 165-6946 Bearing Blocks and 152-3421 Cap Assemblies may be ordered. The existing adjustment shims for the front idler are not used.

Note: New longer bolts and new thicker washers are now used for mounting the cap assemblies and bearing blocks. Two sets of bolts and washers are included in the arrangement. For D6H, use English bolts and washers. For D6R and D6R Series II, use Metric bolts and washers. Be careful to select the proper mounting hardware to avoid damage from cross threaded fasteners. Discard the unused set of hardware.

Preparation of the Undercarriage

1. Separate the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Separate" in the Service Manual for the proper procedure.

2. Remove the front and rear idlers from both sides of the machine. Remove the bearing blocks and shims. Refer to Disassembly and Assembly, "Idlers - Remove" in the Service Manual for the proper procedure.

3. Use a wire brush or a wire wheel to clean the bearing blocks, the caps, the dowels, and the mounting areas on the track roller frame.

4. Tap holes for front idlers to 38.8 mm (1.5276 inch) with a flat bottom tap.

Adjustment of the Dowel Pins

Perform the following procedure on all eight dowel pins.

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Illustration 10	g01005305

4. Inspect the dowel pins on the front and rear track roller frames. The dowel pins should be smooth with no visible wear or shear steps. The dowel pins should fit tightly in the track roller frame. If any dowel pins need replacement, use a new 7T-5886 Dowel Pin.

5. Measure height (A) of the dowel pins. Adjust the height, if necessary. The correct height for the dowel pins in both the front and the rear track roller frame is 28 ± 1 mm (1.10 ± 0.04 inch).

Welding the Permanent Shims

Two different mounting shims for the idler are provided in the arrangement. The shims arevery similar in appearance, but the thickness differs. Shim (2) is 6 mm (0.24 inch) thick. Shim (3) is 10 mm (0.39 inch) thick. Both shims are installed in the mounting of the idlers. However, the thin shim (2) is welded to the front track roller frame. Shim (2) is also used as the adjustment shim on the rear track roller frame. The thick shim (3) is welded to the rear track roller frame. Shim (3) is also used as the adjustment shim for the front track roller frame. The adjustable shims may be removed as the undercarriage wears to adjust the height of the idler.

The shims must not be mixed during this procedure. Locate four thick shims (3) and put the shims aside for later use. Also, locate four thin shims (2) and put the shims aside for later use.

Perform the following procedure for all eight mounting blocks.

6. Use a wire brush or a wire wheel to clean the mounting surface for the bearing block on the track roller frame.
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   Illustration 11	g06058597

7. Install shim (2 or 3), bearing block (11), and cap assembly (12) with two bolts (4) and two washers (5). Do not install the idler now.

   Note: Be careful to use the correct bolts and washers. Tractors that are series H use English fasteners. Tractors that are series R use Metric fasteners.

   Note: Some block and cap assemblies have a gap (B) of 3 mm (0.12 inch) on one side only. See Illustration 11. If there is a gap on one side of the block and cap assembly, install the existing 5P-8248 Mounting Washer (D6H) or 8T-3282 Mounting Washer (D6R) in the gap. Install mounting bolt (4) through this washer. This will ensure that the permanent shim is tight against the frame when the idler assembly is not installed. Early cap assemblies do not need a washer because the large one side gap does not exist.

8. Align shim (2) or shim (3) so that the shim is parallel with the rails of the track roller frame. Tighten bolts (4) so that the shim is held tightly to the track roller frame. There is no need to torque the bolts now.

9. Remove the paint from the welding area around the perimeter of the permanent shim.

10. Weld three butt welds on both the outside edge and the inside edge of the shim. Each weld should be 4 mm (0.16 inch) wide by 12 mm (0.47 inch) long . The welds are indicated in Illustration 11.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

11. Remove bolts (4), washers (5), and cap assembly (14). If you placed a washer in gap (B), discard the washer. Do not remove bearing block (13).

12. Repeat Steps 6 through 11 for all eight mounting blocks.

Installation of the Base Plates on the Rear Track Roller Frame

Perform the following procedure for the two rear idlers.

Note: Step 13 through Step 19 is a test procedure. The test procedure is performed to identify proper clearance between the center tread idlers and the rear track roller frame. The test procedure is also performed to locate the rear base plates with the center tread idlers.

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Illustration 12	g06058604

13. On one of the rear track roller frames, install idler (1) on bearing blocks (11). Only the permanent shims should be in place now.

14. Install cap assemblies (12). Align the holes in the idler shaft with the spring pins in the cap assemblies.

15. Install two bolts (4) and two washers (5) in each cap assembly.

16. Tighten the four bolts so the bearing blocks are snug to the track roller frame. The bolts do not need torqued now.

17. Rotate the idler. The idler should rotate freely with no interference. There may be a slight interference between the idler tread and the top plate of the rear track roller frame. If interference exists, remove the idler and grind a clearance in this area. Install the idler. If the idler rotates freely, proceed to the next step.
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    Illustration 13	g06058624

18. Locate base plate (6) on the rear track roller frame. Refer to Illustration 13. Leave a clearance (C) of 6 mm (0.24 inch) between the inside edge of the base plate and the idler tread. The slot in the base plate should be centered and parallel with the idler tread.

19. Rotate the idler. There should be no interference between the base plate and the idler.

20. Remove the paint from the welding area.

21. Tack weld the base plate in place.

22. Remove the idler, the cap assemblies, and the bearing blocks.

23. Skip weld the base plate to the track roller frame with 8 mm (0.3 inch) by 50 mm (2 inch) long fillet welds with 1.5 mm (0.06 inch) penetration around the entire outside edge of the plate. The welds are indicated in Illustration 13.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

24. Repeat Steps 13 through 23 for the other rear idler.

Installation of the Base Plates on the Front Track Roller Frame

Perform the following procedure for the two front idlers.

Note: Step 25 through Step 31 is a test procedure. The test procedure is performed to check for interference between the idler and the front track roller frame. The test is also performed to locate the front base plates with the center tread idlers.

25. On one of the front track roller frames, install idler (1) on bearing blocks (11). Only the permanent shims should be in place now.

26. Install cap assemblies (12). Align the holes in the idler shaft with the spring pins in the cap assemblies.

27. Install two bolts (4) and two washers (5) in each cap assembly.

28. Tighten the four bolts so the bearing blocks are snug to the track roller frame. The bolts do not need torqued now.

29. Rotate the idler. The idler should rotate freely with no interference. If interference exists between the idler and the track roller frame, remove the idler. Grind a clearance to eliminate the interference. Install the idler. If the idler rotates freely, proceed to the next step.
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    Illustration 14	g01005669

30. Locate base plate (6) on the front track roller frame. Refer to Illustration 14. The curved front edge (D) of the plate should be against the curved front edge of the front track roller frame. The slot in the base plate should be centered and parallel with the idler tread.

31. Rotate the idler. There should be no interference between the base plate and the idler.

32. Remove the paint from the welding area.

33. Tack weld the base plate in place.

34. Remove the idler, the cap assemblies, and the bearing blocks.

35. Skip weld the base plate to the track roller frame with 8 mm (0.3 inch) by 50 mm (2 inch) long fillet welds with 1.5 mm (0.06 inch) penetration around the entire outside edge of the plate. The welds are indicated in Illustration 14.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

36. Repeat Steps 25 through 35 for the other front idler.

Installation of Adjustment Shims, Bearing Blocks, and Idlers

Perform the following procedure for all four idlers.

37. Apply 4C-5593 Anti-Seize Compound to the dowel pin holes in the bearing blocks.
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    Illustration 15	g06058626

38. Install one shim (3) or one shim (2) over each dowel pin.

39. Install bearing blocks (11) on the dowel pins.

40. Install idler (1).

41. Install cap assemblies (12). Align the holes in the idler shaft with the spring pins in the cap assemblies.

42. Apply 4C-5593 Anti-Seize Compound to the threads on four bolts (4).

43. Install four bolts (4) and four washers (5) in bearing cap assemblies (12).
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    Illustration 16	g01006462

    Note: For cap assemblies with a gap (B) on one side, tighten the bolt on the abutment side (E) first. "TIGHTEN FIRST" is stamped on the abutment side (D) of the cap assembly. See Illustration 16. For cap assemblies that do not have a gap on one side, there is no marking. The bolts are tightened by alternating evenly. A small gap results on both sides of the cap assembly.

44. Tighten bolts (4) to the specified torque. See Table 6.
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    Table 6

    Torque Specifications
    Model	Bolt Size	Torque
    D6H XL D6H XW D6H IG	3/4 inch	475 ± 60 N·m (350 ± 45 lb ft)
    D6R XL D6R XW	20 mm	570 ± 80 N·m (420 ± 60 lb ft)

45. Repeat Steps 37 through 44 for all four idlers.

Installation of the Rear Scrapers

Perform this procedure for both rear idlers.

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Illustration 17	g06058633

46. Install two side scrapers (7) and one scraper (8) with eight bolts (9) and eight washers (10). Leave a minimum of clearance between the scrapers and the idler.

47. Rotate the idler by one full revolution. The idler should rotate freely. If the idler does not rotate freely, adjust the scrapers to eliminate the interference.

48. Tighten bolts (9).

49. Repeat Steps 46 through 48 for the other rear idler.

Installation of the Front Scrapers

Perform this procedure for both front idlers.

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Illustration 18	g06058656

50. Install two side scrapers (7) and one scraper (8) with eight bolts (9) and eight washers (10). Leave a minimum of clearance between the scrapers and the idler.

51. Rotate the idler by one full revolution. The idler should rotate freely. If the idler does not rotate freely, adjust the scrapers to eliminate the interference.

52. Tighten bolts (9).

53. Repeat Steps 50 through 52 for the other front idler.

Preparation for Service

54. Connect the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Connect" in the Service Manual for the proper procedure.

55. Adjust the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Adjust" in the Service Manual for the proper procedure.

56. Prepare the machine for operation. Refer to the Operation and Maintenance Manual for instructions.

Steps For XL and XW Arrangements on D6R Series III Track-Type Tractor

Necessary Parts

Note: XL and XW undercarriage arrangements use the existing cap assemblies and the existing bearing blocks. If the cap assemblies and bearing blocks need replacement, 165-6946 Bearing Blocks and 152-3421 Cap Assemblies may be ordered. The existing adjustment shims for the front idler are not used.

Note: New longer bolts and new thicker washers are now used for mounting the cap assemblies and bearing blocks. For D6R Series III, use Metric bolts and washers.

Preparation of the Undercarriage

1. Separate the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Separate" in the Service Manual for the proper procedure.

2. Remove the front and rear idlers from both sides of the machine. Remove the bearing blocks and shims. Refer to Disassembly and Assembly, "Idlers - Remove" in the Service Manual for the proper procedure.

3. Use a wire brush or a wire wheel to clean the bearing blocks, the caps, the dowels, and the mounting areas on the track roller frame.

Adjustment of the Dowel Pins

Perform the following procedure on all eight dowel pins.

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Illustration 19	g01005305

4. Inspect the dowel pins on the front and rear track roller frames. The dowel pins should be smooth with no visible wear or shear steps. The dowel pins should fit tightly in the track roller frame. If any dowel pins need replacement, use a new 7T-5886 Dowel Pin.

5. Measure height (A) of the dowel pins. Adjust the height, if necessary. The correct height for the dowel pins in both the front and the rear track roller frame is 28 ± 1 mm (1.10 ± 0.04 inch).

Welding the Permanent Shims

Two different mounting shims for the idler are provided in the arrangement. The shims arevery similar in appearance, but the thickness differs. Shim (2) is 6 mm (0.24 inch) thick. Shim (3) is 10 mm (0.39 inch) thick. Both shims are installed in the mounting of the idlers. However, the thin shim (2) is welded to the front track roller frame. Shim (2) is also used as the adjustment shim on the rear track roller frame. The thick shim (3) is welded to the rear track roller frame. Shim (3) is also used as the adjustment shim for the front track roller frame. The adjustable shims may be removed as the undercarriage wears to adjust the height of the idler.

The shims must not be mixed during this procedure. Locate four thick shims (3) and put the shims aside for later use. Also, locate four thin shims (2) and put the shims aside for later use.

Perform the following procedure for all eight mounting blocks.

6. Use a wire brush or a wire wheel to clean the mounting surface for the bearing block on the track roller frame.
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   Illustration 20	g01291844

7. Install shim (2 or 3), bearing block (13), and cap assembly (14) with two bolts (4) and two washers (5). Do not install the idler now.

   Note: Some block and cap assemblies have a gap (B) of 3 mm (0.12 inch) on one side only. See Illustration 20. If there is a gap on one side of the block and cap assembly, install the existing 8T-3282 Mounting Washer in the gap. Install mounting bolt (4) through this washer. This will ensure that the permanent shim is tight against the frame when the idler assembly is not installed. Early cap assemblies do not need a washer because the large one side gap does not exist.

8. Align shim (2) or shim (3) so that the shim is parallel with the rails of the track roller frame. Tighten bolts (4) so that the shim is held tightly to the track roller frame. There is no need to torque the bolts now.

9. Remove the paint from the welding area around the perimeter of the permanent shim.

10. Weld three butt welds on both the outside edge and the inside edge of the shim. Each weld should be 4 mm (0.16 inch) wide by 12 mm (0.47 inch) long . The welds are indicated in Illustration 20.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

11. Remove bolts (4), washers (5), and cap assembly (14). If you placed a washer in gap (B), discard the washer. Do not remove bearing block (13).

12. Repeat Steps 6 through 11 for all eight mounting blocks.

Installation of the Base Plates on the Rear Track Roller Frame

Perform the following procedure for the two rear idlers.

Note: Step 13 through Step 23 is a test procedure. The test procedure is performed to identify proper clearance between the center tread idlers and the rear track roller frame. The test procedure is also performed to locate the rear base plates with the center tread idlers.

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Illustration 21	g01005638

13. On one of the rear track roller frames, install idler (1) on bearing blocks (13). Only the permanent shims should be in place now.

14. Install cap assemblies (14). Align the holes in the idler shaft with the spring pins in the cap assemblies.

15. Install two bolts (4) and two washers (5) in each cap assembly.

16. Tighten the four bolts so the bearing blocks are snug to the track roller frame. The bolts do not need torqued now.

17. Rotate the idler. The idler should rotate freely with no interference. There may be a slight interference between the idler tread and the top plate of the rear track roller frame. If interference exists, remove the idler and grind a clearance in this area. Install the idler. If the idler rotates freely, proceed to the next step.
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    Illustration 22	g01005640

18. Locate base plate (7) on the rear track roller frame. Refer to Illustration 22. Leave a clearance (C) of 6 mm (0.24 inch) between the inside edge of the base plate and the idler tread. The slot in the base plate should be centered and parallel with the idler tread.

19. Rotate the idler. There should be no interference between the base plate and the idler.

20. Remove the paint from the welding area.

21. Tack weld the base plate in place.

22. Remove the idler, the cap assemblies, and the bearing blocks.

23. Skip weld the base plate to the track roller frame with 8 mm (0.3 inch) by 50 mm (2 inch) long fillet welds with 1.5 mm (0.06 inch) penetration around the entire outside edge of the plate. The welds are indicated in Illustration 22.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

24. Repeat Steps 13 through 23 for the other rear idler.

Installation of the Base Plates on the Front Track Roller Frame

Perform the following procedure for the two front idlers.

Note: Step 25 through Step 35 is a test procedure. The test procedure is performed to check for interference between the idler and the front track roller frame. The test is also performed to locate the front base plates with the center tread idlers.

25. On one of the front track roller frames, install idler (1) on bearing blocks (13). Only the permanent shims should be in place now.

26. Install cap assemblies (14). Align the holes in the idler shaft with the spring pins in the cap assemblies.

27. Install two bolts (4) and two washers (5) in each cap assembly.

28. Tighten the four bolts so the bearing blocks are snug to the track roller frame. The bolts do not need torqued now.

29. Rotate the idler. The idler should rotate freely with no interference. If interference exists between the idler and the track roller frame, remove the idler. Grind a clearance to eliminate the interference. Install the idler. If the idler rotates freely, proceed to the next step.
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    Illustration 23	g01005669

30. Locate base plate (6) on the front track roller frame. Refer to Illustration 23. The curved front edge (D) of the plate should be against the curved front edge of the front track roller frame. The slot in the base plate should be centered and parallel with the idler tread.

31. Rotate the idler. There should be no interference between the base plate and the idler.

32. Remove the paint from the welding area.

33. Tack weld the base plate in place.

34. Remove the idler, the cap assemblies, and the bearing blocks.

35. Skip weld the base plate to the track roller frame with 8 mm (0.3 inch) by 50 mm (2 inch) long fillet welds with 1.5 mm (0.06 inch) penetration around the entire outside edge of the plate. The welds are indicated in Illustration 23.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

36. Repeat Steps 25 through 35 for the other front idler.

Installation of Adjustment Shims, Bearing Blocks, and Idlers

Perform the following procedure for all four idlers.

37. Apply 4C-5593 Anti-Seize Compound to the dowel pin holes in the bearing blocks.
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    Illustration 24	g01291855

38. Install one shim (3) or one shim (2) over each dowel pin.

39. Install bearing blocks (13) on the dowel pins.

40. Install idler (1).

41. Install cap assemblies (14). Align the holes in the idler shaft with the spring pins in the cap assemblies.

42. Apply 4C-5593 Anti-Seize Compound to the threads on four bolts (4).

43. Install four bolts (4) and four washers (5) in bearing cap assemblies (14).
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    Illustration 25	g01006462

    Note: For cap assemblies with a gap (B) on one side, tighten the bolt on the abutment side (E) first. "TIGHTEN FIRST" is stamped on the abutment side (D) of the cap assembly. See Illustration 25. For cap assemblies that do not have a gap on one side, there is no marking. The bolts are tightened by alternating evenly. A small gap results on both sides of the cap assembly.

44. Tighten bolts (4) to 570 ± 80 N·m (420 ± 60 lb ft).

45. Repeat Steps 37 through 44 for all four idlers.

Installation of the Rear Scrapers

Perform this procedure for both rear idlers.

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Illustration 26	g01005686

46. Install two side scrapers (9) and one scraper (10) with eight bolts (11) and eight washers (12). Leave a minimum of clearance between the scrapers and the idler.

47. Rotate the idler by one full revolution. The idler should rotate freely. If the idler does not rotate freely, adjust the scrapers to eliminate the interference.

48. Tighten bolts (11).

49. Repeat Steps 46 through 48 for the other rear idler.

Installation of the Front Scrapers

Perform this procedure for both front idlers.

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Illustration 27	g01005729

50. Install two side scrapers (8) and one scraper (10) with eight bolts (11) and eight washers (12). Leave a minimum of clearance between the scrapers and the idler.

51. Rotate the idler by one full revolution. The idler should rotate freely. If the idler does not rotate freely, adjust the scrapers to eliminate the interference.

52. Tighten bolts (11).

53. Repeat Steps 50 through 52 for the other front idler.

Installation of Front Lower Scrapers

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Illustration 28	g01284407
Right Front Track Roller Frame that is shipped from the factory

54. Create a paper template for 283-5250 Plate As.

55. Align the top edge (A) and outside edge (B) of the paper template for 283-5250 Plate As with the existing outside scraper plate (C). Then tape the paper template to the existing plate.

    Note: The position of 283-5250 Plate As (15) must allow clearance for the removal of the idler.

    Note: If the frames are bent, align the plates to accommodate the best fit for the scraper and provide clearance for the removal of the idler.

56. Mark the center locations on the existing outside scraper plate (C) with a center punch for three 30 mm (1.181 inch) hole diameters (E).

57. Remove the paper template from the track roller frame.
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    Illustration 29	g01284428
    The Right Front Track Roller Frame with three 30 mm (1.181 inch) burnt holes

58. Outline a 30 mm (1.181 inch) hole (E) around each of the locations that were marked with the center punch. By using a punch, make four marks. Make sure that the marks are every ninety degrees around the outside of the 30 mm (1.181 inch) holes.

    Note: One of the 30 mm (1.181 inch) holes (E) will not be a complete hole.

    Note: The 30 mm (1.181 inch) holes (E) will provide clearance for the weld nuts on the 283-5250 Plate As.

59. Use the marked holes as a reference and burn three 30 mm (1.181 inch) holes (E) with a torch in the existing scraper plate (C).

60. Grind a 6 mm (0.236 inch) bevel on the outside edge (B) and the bottom edge (G) of the scraper plate (C) from point (D) to point (F).

61. Remove paint and debris from welding surfaces.
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    Illustration 30	g01293629
    The Right Front Track Roller Frame after 283-5250 Plate As is installed.

62. Locate 283-5250 Plate As (15) by aligning the top (A) and outside (B) edges of the plate (15) with the existing outside scraper plate (C). Tack weld the plate in place with a 25 mm (0.984 inch) weld length at the bottom (G) and outside (B) edges.

63. Complete two 8 mm (0.315 inch)plug welds in the two larger holes (H) of the 283-5250 Plate As (15).

64. Complete an 8 mm (0.315 inch) groove weld at a 45 degree angle completely across the bottom edge (G) of the plate (15) to the beginning of notch (AA) without making contact with the track link.

65. Complete an 8 mm (0.315 inch) fillet weld completely across the top edge (A) of the plate (15).

    Note: To perform this weld, stick welding will be required as this is the only method that will allow access to the top edge of the plate.

66. Complete an 8 mm (0.315 inch) groove weld across the complete outside edge (B) of the plate (15) starting at the bottom (G) and welding upward toward the top (A).

67. Remove any weld splatter and debris from all mating surfaces.
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    Illustration 31	g01293686
    The Right Front Track Roller Frame after 282-4017 Scraper Plate is installed.

68. Assemble the 282-4017 Scraper (13) to the 283-5250 Plate As (15) with three 8T-4194 Bolts (18) and three 5P-1076 Hard Washers (10). Torque the bolts to 100 ± 20 N·m (75 ± 15 lb ft).

    Note: After the scraper plate is installed, slide the scraper plate against the side of the idler. Move the scraper away from the idler 5 mm (0.197 inch) to allow clearance of the raised letters.

69. Repeat steps 54 through 68 in "Installation of Front Lower Scrapers" for the inside scraper plate that will use 283-5249 Plate As (14) instead of the 283-5250 Plate As (15).

    Note: The inside scraper will use the following parts: 282-4017 Scraper Plate (13), three 8T-4194 Bolts (18) and three 5P-1076 Hard Washers (10).

70. Repeat steps 54 through 69 for the other front lower scraper.

    Note: To install the left front scraper, use 283-5249 Plate As (14) instead of 283-5250 Plate As (15) for the outside. Then use 283-5250 Plate As (15) instead of 283-5249 Plate As (14) for the inside.

Installation of Rear Lower Scrapers

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Illustration 32	g01284503
Right Rear Track Roller Frame that is shipped from the factory

71. Create a paper template for the part number 283-5251 Plate As (16).

72. Align the top edge (A) and outside edge (B) of the paper template for 283-5251 Plate As with the existing outside scraper plate (C). Then tape the paper template to the existing plate.

    Note: The position of 283-5251 Plate As (16) must allow clearance for the removal of the idler.

    Note: If the frames are bent, align the plates to accommodate the best fit for the scraper and provide clearance for the removal of the idler.

73. Mark the center locations on the existing outside scraper plate (C) with a center punch for three 30 mm (1.181 inch) diameter holes (E).

74. Remove the paper template from the track roller frame.
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    Illustration 33	g01284513
    Right Rear Track Roller Frame with three burnt 30 mm (1.181 inch) holes

75. Outline a 30 mm (1.181 inch) hole (E) around each of the locations that were marked with the center punch. By using a punch, make four marks. Make sure that the marks are every ninety degrees around the outside of the 30 mm (1.181 inch) hole.

    Note: One of the 30 mm (1.181 inch) holes (E) will not be a complete hole.

    Note: The 30 mm (1.181 inch) hole diameter (E) will provide clearance for the weld nuts on the 283-5251 Plate As.

76. Use the marked holes as a reference and burn three 30 mm (1.181 inch) holes with an oxyacetylene torch in the existing scraper plate (C).

77. Grind a 6 mm (0.236 inch) bevel on the outside edge (B) and the bottom edge (G) of the scraper plate (C) from point (D) to point (F).

78. Remove paint and debris from welding surfaces.
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    Illustration 34	g01293698
    The Right Rear Track Roller Frame after 283-5251 Plate As is installed.

79. Locate 283-5251 Plate As (16) by aligning the top (A) and outside (B) edges of the plate with the existing outside scraper plate (C). Tack weld the plate (16) in place with a 25 mm (0.984 inch) long weld at the bottom (G) and outside (B) edges.

80. Complete two 8 mm (0.315 inch)plug welds in the two larger holes (H) of the 283-5251 Plate As (16).

81. Complete an 8 mm (0.315 inch) groove weld at a 45 degree angle completely across the bottom edge (G) of the plate (16) to the beginning of notch (AA) without making contact with the track link.

82. Complete an 8 mm (0.315 inch) fillet weld completely across the top edge (A) of the plate (16).

    Note: To perform this weld, stick welding will be required as this is the only method that will allow access to the top edge of the plate.

83. Complete an 8 mm (0.315 inch) groove weld across the complete outside edge (B) of the plate (16) starting at the bottom (G) and welding upward toward the top (A).

84. Remove any weld splatter and debris from all mating surfaces.
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    Illustration 35	g01293701
    The Right Rear Track Roller Frame after 282-4017 Scraper Plate is installed.

85. Assemble the 282-4017 Scraper Plate (13) to the 283-5251 Plate As (16) with three 8T-4194 Bolts (18) and three 5P-1076 Hard Washers (10). Torque the bolts to 100 ± 20 N·m (75 ± 15 lb ft).

    Note: When the scraper plate is installed, slide the scraper plate against the side of the idler. Move the scraper away from the idler 5 mm (0.197 inch). This will allow clearance for the raised letters that are on the idler.

86. Repeat steps 71 through 85 in "Installation of Rear Lower Scrapers" for the inside scraper plate that will use 283-5252 Plate As (17) instead of the 283-5251 Plate As (16).

    Note: The inside scraper will use the following: 282-4017 Scraper Plate (13), three 8T-4194 Bolts (18) and three 5P-1076 Hard Washers (10).

87. Repeat steps 71 through 86 for the other rear lower scraper.

    Note: To install the left rear scraper, use 283-5252 Plate As (17) instead of 283-5251 Plate As (16) for the outside. Then use 283-5251 Plate As (16) instead of 283-5252 Plate As (17) for the inside.

Preparation for Service

88. Connect the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Connect" in the Service Manual for the proper procedure.

89. Adjust the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Adjust" in the Service Manual for the proper procedure.

90. Prepare the machine for operation. Refer to the Operation and Maintenance Manual for instructions.

LGP Undercarriage Arrangements

Necessary Parts

Illustration 36	g01293621
The Lower Scraper is installed.

Reference: Refer to Special Instruction, REHS2937, "Installation Of Lower Scrapers On Center Tread Idlers" for the installation of the lower scraper.

Note: New longer bolts are now used for mounting the cap assemblies and bearing blocks. Also, note that the mounting bolts for the rear idler are longer than the mounting bolts for the front idler. Two sets of bolts and washers are included in the arrangement. For D6H, use English bolts and washers. For D6R, D6R Series II , and D6R Series III, use Metric bolts and washers. Be careful to select the proper mounting hardware to avoid damage from cross threaded fasteners. Discard the unused set of hardware.

Preparation of the Undercarriage

1. Separate the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Separate" in the Service Manual for the proper procedure.

2. Remove both track roller frames from the machine. Refer to Disassembly and Assembly, "Track Roller Frames - Remove" for the proper procedure.

3. Position the track roller frames upside-down.

4. Remove the front and rear idlers from the track roller frames. Refer to Disassembly and Assembly, "Idlers - Remove" in the Service Manual for the proper procedure.

5. Remove the bearing blocks from the front and rear track roller frames. Also, remove the adjustment shims for the front idlers.

6. Clean the track roller frame under the bearing blocks and around the dowel pins with a wire brush or a wire wheel. The mounting surface must be clean and flat.

Drilling and Tapping of the Rear Track Roller Frame

This procedure adds two additional threaded mounting holes to each rear track roller frame. These holes are used for mounting the new longer bearing blocks. The new bearing blocks locate the shaft of the rear center tread idler in an offset position.

This procedure requires welding and machining on the track roller frame. Do not attempt to perform this procedure without a drill with a magnetic base.

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Illustration 37	g00989265

7. On one of the rear track roller frames, install one rear shim (3) on each dowel pin. The shims must be positioned correctly. One end of the shim is longer from the center of the dowel hole. Position the long end of the shim toward the end of the rear track roller frame.

8. Install one rear bearing block (5) on each dowel pin. The bearing blocks aredesigned to be installed in one direction only. The bearing blocks must be positioned correctly. The end that is marked "UP" (D) is positioned toward the end of the track roller frame.

9. Install rear idler (1) on the bearing blocks.

10. Place a transfer punch or a center punch (E) in the rear holes of the bearing blocks (near end "D"). Mark the new hole locations on the track roller frame. Punch (E) must be centered in the bolt hole. See Illustration 37.

11. Remove the idler assembly, the bearing blocks, and the shims.

12. Center punch the marks for the new hole locations.
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    Illustration 38	g00989267

13. Weld a suitable plate (F) on the track roller frame to support the portable magnetic drill. Plate (F) should span both supports on the track roller frame. Support plate (F) with a brace (N) to avoid deflecting the plate.

14. Install center drill (G) in portable magnetic drill (A). See Illustration 38.

15. Locate portable magnetic drill (A) on plate (F) on the track roller frame. Center drill (G) must be perpendicular to the track roller frame.

16. Use portable magnetic drill (A) and center drill (G) to drill a pilot hole.

17. Remove the center drill from the portable magnetic drill.
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    Illustration 39	g00989268

18. Install drill bit (B) in portable magnetic drill (A). Make sure that drill bit (B) is perpendicular to the track roller frame.

19. Use portable magnetic drill (A) and drill bit (B) to drill the new hole. Do not drill through the top plate on the rail of the track roller frame.

20. Repeat Steps 14 through 19 for the other frame rail of the rear track roller frame.
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    Illustration 40	g00989270

21. Use tap (C) to tap the new holes. Use a combination square (H) to make sure that the tap is perpendicular to the track roller frame.

    Note: If the portable magnetic drill has a torque limiter, use the portable magnetic drill to start the tap.

22. Remove support plate (F) and brace (N) from the track roller frame.

23. Clean the surface under the bearing blocks. The surface must be clean and flat.

24. Repeat Steps 7 through 23 for the other rear track roller frame.

25. Position the track roller frames upright.

26. Install the track roller frames on the machine. Refer to Disassembly and Assembly, "Track Roller Frames - Install" for the proper procedure.

Adjustment of the Dowel Pins

Perform the following procedure on all eight dowel pins.

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Illustration 41	g01005926

27. Inspect the dowel pins on the front and rear track roller frames. The dowel pins should be smooth with no visible wear or shear steps. The dowel pins should fit tightly in the track roller frame.

28. Measure height (J) of the dowel pins. Adjust the height, if necessary. The correct heights for the dowel pins are shown in Table 12.

    Note: The dowel pins may be difficult to pull out. If necessary, you may drive the dowel pin completely into the frame. Then, insert a new 7T-5886 Dowel Pin.

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    Table 12

    Heights of the Dowel Pins for LGP Undercarriages
    Location	Height
    Front	19 ± 1 mm (0.75 ± 0.04 inch)
    Rear	29 ± 1 mm (1.14 ± 0.04 inch)

Welding the Permanent Shims on the Rear Track Roller Frame

For the rear center tread idlers, two mounting shims (3) are used under each bearing block to properly position the idler. One permanent shim is welded to the track roller frame. One adjustment shim is not welded. The adjustment shim may be removed as the undercarriage wears to adjust the height of the idler.

Note: No shims are welded on the front track roller frames.

Perform the following procedure on the rear idlers only.

29. Use a wire brush or a wire wheel to clean the mounting surface for the bearing block on the rear track roller frame.
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    Illustration 42	g01005965

30. On one of the rear track roller frames, install one rear shim (3) and bearing block (5) on each dowel pin. Position the bearing blocks and the shims correctly. The longer end of the shim goes toward the end of the track roller frame. The end of the bearing block that is marked "UP" goes toward the end of the track roller frame.

31. Install cap assembly (7) on each bearing block with two bolts (9) and two washers (10). Do not install the idler now.

    Note: The existing mounting bolts and washers are not reused. Be careful to use the correct new bolts and new washers. Tractors that are series H use English fasteners. Tractors that are series R use Metric fasteners. Also, the rear mounting bolts are longer than the front mounting bolts.

    Note: The block and cap assemblies have a gap (K) of 3 mm (0.12 inch) on one side only. Install the existing 5P-8248 Mounting Washer (D6H) or 8T-3282 Mounting Washer (D6R) in the gap. Install mounting bolt (9) through this washer. This will ensure that the permanent shim is tight against the frame when the idler assembly is not installed. See Illustration 42.

32. Align shims (3) so that the shims are parallel with the rails of the track roller frame. Tighten bolts (9) so that the shims are held tightly to the track roller frame. There is no need to torque the bolts now.

33. Remove the paint from the welding area around the perimeter of the permanent shims.

34. Weld three butt welds on both the outside edge and the inside edge of each shim. Each weld should be 4 mm (0.16 inch) wide by 12 mm (0.47 inch) long . The welds are indicated in Illustration 42.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

35. Remove bolts (9), washers (10), and cap assemblies (7). If you placed a washer in gap (K), discard the washer. Do not remove bearing blocks (5).

36. Repeat Steps 29 through 35 for the other rear track roller frame.

Installation of the Base Plates

37. On both of the front track roller frames, install bearing blocks (4) on the dowel pins. Position the bearing blocks correctly. The end of the bearing block that is marked "UP" goes toward the end of the track roller frame. Do not install the adjustment shims on the front track roller frame now.

    Note: Step 38 through Step 50 is a test procedure. The test procedure is performed to identify proper clearance between the center tread idlers and the track roller frame. The test procedure is also performed to locate the base plates with the center tread idlers.

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    Illustration 43	g01006080

38. On one of the front track roller frames, install idler (1) on bearing blocks (4).

39. Install cap assemblies (6). Align the holes in the idler shaft with the spring pins in the cap assemblies.

40. Install two bolts (8) and two washers (10) in each cap assembly.

    Note: The existing mounting bolts and washers are not reused. Be careful to use the correct new bolts and new washers. Tractors that are series H use English fasteners. Tractors that are series R use Metric fasteners. Also, the front mounting bolts are shorter than the rear mounting bolts.

41. Tighten bolts (8) so the two bearing blocks are snug to the track roller frame. The bolts do not need torqued now.

42. Repeat Steps 38 through 41 for the other front track roller frame.
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    Illustration 44	g01006083

43. On one of the rear track roller frames, install idler (1) on bearing blocks (5).

    Note: Only welded shims (3) should be in place now.

44. Install cap assemblies (7). Align the holes in the idler shaft with the spring pins in the cap assemblies.

45. Install two bolts (9) and two washers (10) in each cap assembly.

46. Tighten bolts (9) so the two bearing blocks are snug to the track roller frame. The bolts do not need torqued now.

47. Repeat Steps 43 through 46 for the other rear track roller frame.

48. Rotate all four idlers. The idlers should rotate freely with no interference. If interference exists between the idler tread and the track roller frame, remove the idler and grind a clearance. Install the idler. When all the idlers rotate freely, proceed to the next step.
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    Illustration 45	g01006091

49. Locate base plate (11) on the track roller frame for each of the four idlers. Refer to Illustration 45. Leave a clearance (L) of 6 mm (0.24 inch) between the inside edge of the base plate and the idler tread. The slot in the base plate should be centered and parallel with the idler tread.

50. Rotate each of the four idlers. There should be no interference between the base plates and the idlers.

51. Remove the paint from the welding area around all four base plates.

52. Tack weld the four base plates in place.

53. Remove the idlers, the cap assemblies, and the bearing blocks.

54. Skip weld the four base plates to the track roller frame with 8 mm (0.3 inch) by 50 mm (2 inch) long fillet welds with 1.5 mm (0.06 inch) penetration around the outside edges of the plates. The welds are indicated in Illustration 45.

    Note: Use a dry low hydrogen E7018 welding rod or E70T-5 cored wire with CO2 gas shielding. Do not use E70T-1 cored wire with CO2 gas shielding.

Installation of Adjustment Shims, Bearing Blocks, and Idlers on the Front Track Roller Frames

Perform the following procedure for both front idlers.

55. On one of the front track roller frames, apply 4C-5593 Anti-Seize Compound to the dowel pin holes in the bearing blocks.
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    Illustration 46	g01006101

56. Install one adjustment shim (2) over each dowel pin.

57. Install bearing blocks (4) on the dowel pins. Position the bearing blocks correctly. The end of the bearing block that is marked "UP" goes toward the end of the track roller frame.

58. Install front idler (1).

59. Install cap assemblies (6). Align the holes in the idler shaft with the spring pins in the cap assemblies.

60. Apply 4C-5593 Anti-Seize Compound to the threads of four bolts (8).

61. Install four bolts (8) and four washers (10) in cap assemblies (6).
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    Illustration 47	g01006106

    Note: The block and cap assemblies have a gap (K) on one side only. Tighten the bolt on the abutment side (M) first. "TIGHTEN FIRST" is stamped on the abutment side (M) of the cap assembly. See Illustration 47.

62. Tighten the bolts to the specified torque. See Table 13.
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    Table 13

    Torque Specifications
    Model	Bolt Size	Torque
    D6H LGP	3/4 inch	475 ± 60 N·m (350 ± 45 lb ft)
    D6R LGP	20 mm	570 ± 80 N·m (420 ± 60 lb ft)

63. Repeat Steps 55 through 62 for the other front track roller frame.

Installation of Adjustment Shims, Bearing Blocks, and Idlers on the Rear Track Roller Frames

Perform the following procedure for both rear idlers.

64. On one of the rear track roller frames, apply 4C-5593 Anti-Seize Compound to the dowel pin holes in the bearing blocks.
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    Illustration 48	g01006107

65. Place one adjustment shim (3) over each dowel pin next to the welded permanent shim.

66. Install bearing blocks (5) on the dowel pins. Position the bearing blocks correctly. The end of the bearing block that is marked "UP" goes toward the end of the track roller frame.

67. Install rear idler (1).

68. Install cap assemblies (7). Align the holes in the idler shaft with the spring pins in the cap assemblies.

69. Apply 4C-5593 Anti-Seize Compound to the threads of four bolts (9).

70. Install four bolts (9) and four washers (10) in cap assemblies (7).
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    Illustration 49	g01013717

    Note: The block and cap assemblies have a gap (K) on one side only. Tighten the bolt on the abutment side (M) first. "TIGHTEN FIRST" is stamped on the abutment side (M) of the cap assembly. See Illustration 49.

71. Tighten the bolts to the specified torque. See Table 14.
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    Table 14

    Torque Specifications
    Model	Bolt Size	Torque
    D6H LGP	3/4 inch	475 ± 60 N·m (350 ± 45 lb ft)
    D6R LGP	20 mm	570 ± 80 N·m (420 ± 60 lb ft)

72. Repeat Steps 64 through 71 for the other rear track roller frame.

Installation of the Scrapers

Perform this procedure for all four idlers.

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Illustration 50	g01006108

73. Install two side scrapers (12) and one scraper (13) with eight bolts (14) and eight washers (15). Leave a minimum of clearance between the scrapers and the idler.

74. Rotate the idler by one full revolution. The idler should rotate freely. If the idler does not rotate freely, adjust the scrapers to eliminate the interference.

75. Tighten bolts (14).

76. Repeat Steps 73 through 75 for all four idlers.

Preparation for Service

77. Connect the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Connect" in the Service Manual for the proper procedure.

78. Adjust the track on both sides of the machine. Refer to Disassembly and Assembly, "Track - Adjust" in the Service Manual for the proper procedure.

79. Prepare the machine for operation. Refer to the Operation and Maintenance Manual for instructions.