- Track-Type Tractor:
- D6H (S/N: 1KD1-UP; 2KD1-UP; 3ED1-UP; 3YG1-UP; 3ZF1-UP; 4YF1-UP; 2TG1-UP; 4GG1-UP; 4LG1-UP; 4RC1-UP; 8ZJ1-UP; 9KJ1-UP; 2DK1-UP; 5KK1-UP; 6CK1-UP; 8KK1-UP; 8SK1-UP; 9LK1-UP; 9RK1-UP; 1YL1-UP; 2BL1-UP; 2TL1-UP; 1FJ1-UP; 5HF1-UP; 6FC1-UP; 8FC1-UP; 6CF1-UP; 7PC1-UP; 7ZK1-UP; 8KB1-UP; 8YC1-UP)
- D6R (S/N: 2HM1-UP; 4FM1-UP; 8TM1-UP; 9BM1-UP; 2YN1-UP; 3ZN1-UP; 4HN1-UP; 4MN1-UP; 5LN1-UP; 6JN1-UP; 7KN1-UP; 8LN1-UP; 8XN1-UP; 9MN1-UP; 9PN1-UP; 4JR1-UP; 4TR1-UP; 4WR1-UP; 5PR1-UP; 5RR1-UP; 6FR1-UP; 6GR1-UP; 6HR1-UP; 6MR1-UP; 7AR1-UP; 7CR1-UP; 7DR1-UP; 7GR1-UP; 9ZS1-UP; 1RW1-UP)
- D7H (S/N: 5BF1-3999, 4000-UP; 4FG1-3999, 4000-UP; 79Z1-3999, 4000-UP; 80Z1-3999, 4000-UP)
- D7R (S/N: 9HM1-UP; 2EN1-UP; 3DN1-UP; 2HR1-UP; 3ZR1-UP; 4SR1-UP; 5MR1-UP; 6ER1-UP)
- D8L (S/N: 4FB1-UP; 7YB1-UP; 7JC1-UP; 53Y1-UP)
- D8N (S/N: 8WC1-UP; 9TC1-UP; 1XJ1-UP; 5TJ1-UP; 7TK1-UP)
- D9L (S/N: 14Y1-UP)
- D9N (S/N: 1JD1-UP; 6XJ1-UP)
- D9R (S/N: 7TL1-UP; 8BL1-UP)
- D10 (S/N: 84W1-UP; 76X1-UP)
- D10N (S/N: 2YD1-UP; 3SK1-UP)
- D11N (S/N: 4HK1-UP; 74Z1-UP)
- D6R (S/N: 2HM1-UP; 4FM1-UP; 8TM1-UP; 9BM1-UP; 2YN1-UP; 3ZN1-UP; 4HN1-UP; 4MN1-UP; 5LN1-UP; 6JN1-UP; 7KN1-UP; 8LN1-UP; 8XN1-UP; 9MN1-UP; 9PN1-UP; 4JR1-UP; 4TR1-UP; 4WR1-UP; 5PR1-UP; 5RR1-UP; 6FR1-UP; 6GR1-UP; 6HR1-UP; 6MR1-UP; 7AR1-UP; 7CR1-UP; 7DR1-UP; 7GR1-UP; 9ZS1-UP; 1RW1-UP)
- Pipelayer:
- 572R (S/N: 2HZ1-UP)
- 578 (S/N: 8HB1-UP)
- 589 (S/N: 31Z1-UP)
- 578 (S/N: 8HB1-UP)
Introduction
The procedure in this Special Instruction is for the disassembly of a front track roller frame with damaged guide key slot and/or weld connections.
Read this Special Instruction and understand the information in this Special Instruction before you perform any procedure in this publication and before you order any components.
Reference: Refer to the Disassembly and Assembly, "Track Roller Frame, Disassemble and Assemble" in the Service Manual for your machine. The additional information here includes procedures and a complete list of tools.
Warnings
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Personal injury can result from performing service on the track roller frame. Refer to Special Instruction, SMHS8273 for inspection and removal procedures before performing any service. |
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Personal injury or death can result from a compressed recoil spring being released suddenly using incorrect disassembly procedures. A recoil spring that is still held in compression can result in the recoil spring being released unexpectedly with extreme force which could cause serious injury or death. Make sure that the correct disassembly procedure is used, if a front track roller frame that has a crack in the parent metal or weld connection (or a tubular section that has separated from the front of the frame assembly) when the recoil spring is still held in compression. Refer to Special Instruction, SMHS8273 which contains the disassembly procedure that must be used to decrease the possibility of injury while performing service on the track roller frame. |
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Personal injury can result from the track coming off of the roller frame. The track can move off the track roller frame very quickly when a separation of the track is made. Keep away from the front of the machine when the track is removed from the track roller frame. |
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Stop disassembly if evidence of a crack exists in the tube or slot beneath this guide. A cracked tube can break suddenly expelling pieces with great force that could result in serious injury or death. Contact a Caterpillar dealer for special disassembly instructions. |
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Inspection
Perform the following inspection of the track roller frames:
- Release the pressure in the hydraulic track adjuster. Refer to the Operation and Maintenance Manual, "Track Adjustment - Adjust" in the Service Manual for your machine for this procedure. Make sure that all of the pressure has been released. Follow Steps 2 and 3 for a D8 machine or for a larger track-type machine. Follow Steps 4 and 5 for a medium track-type machine (D6 or D7).
- Remove cover (1) and guide (2) on each side of the track roller frame.
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| Illustration 1 | g00545033 |
Typical track roller frame of a large machine (D8L) (1) Cover (2) Guide | |
- Inspect guide slot (3) for cracks in the radial area at the front of the slot. Inspect both sides. Use these openings for the inspection for breaks in the track roller frame at location (A). Check for oil leaks from underneath bearing sleeve (4). A crack at location (B) may produce leaks from the bearing sleeve. A plate is welded to the track roller frame at location (B). Cracks may also develop at locations (C) and (D) (welds). D8L machines and earlier D9L machines are the machines with location (B) .
Note: The roller frame may be cracked at location (B), (C) or (D), even if oil is not visible. Another indication of a broken front track roller is tight track tension. Normally, when a track roller frame breaks, the recoil spring will expand the roller frame and this expansion will create a tight track.
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| Illustration 2 | g00545034 |
Typical front track roller frame of a large machine (D8L) (3) Guide slot (4) Bearing sleeve (A) Location to check for crack (B) Location to check for crack (weld) (C) Location to check for crack (weld) (D) Location to check for crack (weld) | |
- Remove guide assembly (5) on each side of the track roller frame.
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| Illustration 3 | g00544901 |
Typical track roller frame of a medium machine (D7R) (5) Guide assembly | |
- Inspect guide slot (6) for cracks in the radial area at the front of the slot. Inspect both sides. Use these openings for the inspection for breaks in the track roller frame at location (E). Check for oil leaks from underneath bearing sleeve (7). A crack in the track roller frame may produce leaks from the bearing sleeve. Cracks may also develop at location (F) (weld).
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| Illustration 4 | g00544886 |
Typical front track roller frame of a medium machine (D7R) (6) Guide slot (7) Bearing sleeve (E) Location to check for crack (tube connection) (F) Location to check for crack (weld) | |
Disassembly of Intact Front Track Roller Frame
Inspect the track roller frame and inspect the guide key slots. When no evidence of damage is found, follow the procedure in the Service Manual for your machine.
Reference: Refer to the Disassembly and Assembly (Power Train), "Disassembly and Assembly of Track Roller Frames" in the Service Manual for your machine.
If the condition of the front track roller frame cannot be determined, follow the procedure in ""Disassembly of Cracked Front Track Roller Frame" " in this Special Instruction.
Disassembly of Broken Front Track Roller Frame
Inspect the track roller frame and inspect the guide key slots. When the inspection indicates that the front track roller frame is broken into two pieces, use this procedure for disassembly of the front track roller frame:
- Start the engine. Position the machine so that the master link on the track is between the sprocket and the rear idler.
Note: Make sure that enough clear space is in front of the machine for a straight extension of the track.
- Put a support (heavy wood block) at the rear idler between a track grouser and the ground.
- With the engine at low idle, release the opposite steering clutch and engage the foot brake.
- Shift the transmission into the FIRST SPEED REVERSE position. Release the foot brake and slowly increase the engine speed until the track sags between the sprocket and the rear idler.
- Engage the foot brake. Shift the transmission into the NEUTRAL position. Engage the parking brake.
- If the machine is equipped with a bulldozer, move the blade to a full RAISE position. Support the blade in this position. Support of the blade allows a straight extension of the track. The front track roller frame may be removed more easily. Release the foot brake. Stop the engine.
- Remove the bolts that hold the master link together.
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Personal injury can result from the track coming off of the roller frame. The track can move off the track roller frame very quickly when a separation of the track is made. Keep away from the front of the machine when the track is removed from the track roller frame. |
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- Start the engine. With the transmission in the NEUTRAL position, engage the foot brake and release the parking brake. Slowly release the foot brake. The tension in the track turns the sprocket until all of the tension between the track and the front track roller frame is released. Pull the opposite steering control lever in order to keep the machine from moving. Move the transmission selector lever into a forward gear. Drive the track off the sprocket. Put the track in a straight out position in order to remove the front track roller frame. When the preload is released from a recoil spring, the front roller frame can usually be extended beyond the break at the weld. If the recoil spring will not move in the recoil spring housing, the preload will still be on the spring. If the recoil spring will not move in the recoil spring housing, follow the procedure in ""Disassembly of Cracked Front Track Roller Frame" " in this Special Instruction.
Disassembly of Cracked Front Track Roller Frame
Inspect the track roller frame and inspect the guide key slots. When the inspection indicates that the front track roller frame is cracked, use this procedure for disassembly of the front track roller frame. If the condition of the front track roller frame cannot be determined, follow this procedure.
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| Illustration 5 | g00545188 |
Fabricated plates for disassembly of a cracked front track roller frame See Table 1 for dimensions of plates. | |
| Dimensions of Fabricated Plates | |||||
| A | B | C | D | E | |
| D6H / D6R |
50 mm (2.0 inch) | 13 mm (0.5 inch) |
1000 mm (39.4 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D7H / D7R |
50 mm (2.0 inch) |
13 mm (0.5 inch) |
1300 mm (51.1 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D8L | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1176 mm (46.3 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D8N | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1085 mm (42.7 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D9L | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1458 mm (57.4 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D9N/D9R | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1268 mm (49.9 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D10 | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1676 mm (66.0 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D10N | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1555 mm (61.2 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D10N | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1446 mm (56.9 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| D11N | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1840 mm (72.4 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| 572R | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1300 mm (51.1 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| 578 | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1369 mm (53.9 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
| 589 | 50 mm (2.0 inch) |
13 mm (0.5 inch) |
1518 mm (59.8 inch) |
102 mm (4.0 inch) |
28 mm (1.125 inch) |
- Fabricate two plates (1) according to Illustration 5.
- Separate the track from the machine. Follow the procedure in ""Disassembly of Cracked Front Track Roller Frame" " in this Special Instruction.
- Connect a chain or a cable to the front track roller frame. A ratchet puller, a lift truck or another machine can be used to pull apart the track roller frame. Partially separate the front track roller frame from the rear track roller frame. Stop pulling when only the guide key slots are in the rear track roller frame. Inspect weld (2) between the rear casting and the recoil spring housing. Inspect the length of the weld around the front track roller frame. The location of the weld is distance (H) from location (G) in Illustration 6 or in Illustration 7.
Show/hide table
Table 2 Disassembly of Front Track Roller Frame H J D6H
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D6R
398 mm (15.7 inch)
100 mm (3.9 inch)D6H XL
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D6R XL
601 mm (23.7 inch)
100 mm (3.9 inch)D7H
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D7R
912 mm (35.9 inch)
100 mm (3.9 inch)D8L
793 mm (31.2 inch)
100 mm (3.9 inch)D8N
669 mm (26.3 inch)
100 mm (3.9 inch)D9L
938 mm (36.9 inch)
100 mm (3.9 inch)D9N/D9R
782 mm (30.8 inch)
100 mm (3.9 inch)D10
1083 mm (42.6 inch)
100 mm (3.9 inch)D10N
943 mm (37.1 inch)
100 mm (3.9 inch)D10N
834 mm (32.8 inch)
100 mm (3.9 inch)D11N
1139 mm (44.8 inch)
100 mm (3.9 inch)572R
912 mm (35.9 inch)
100 mm (3.9 inch)578
793 mm (31.2 inch)
100 mm (3.9 inch)589
938 mm (36.9 inch)
100 mm (3.9 inch)
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| Illustration 6 | g00545353 |
Typical front track roller frame of a large machine (D8L) See Table 2 for dimensions. | |
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| Illustration 7 | g00545354 |
Typical front track roller frame of a medium machine (D7R) See Table 2 for dimensions. | |
| NOTICE |
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If cracks are found in the weld joints or the guide key slots, immediately push the front track roller frame back into the rear track roller frame until the weld is 100 mm (4 inch) into the rear track roller frame. This precautionary step will keep the broken section inside the rear track roller frame if the front track roller frame breaks. |
- Follow Steps 5 and 6 for large track-type machines. Follow Steps 7 and 8 for medium track-type machines.
- Install one fabricated plate (1) on each side of the track roller frames with four 5B-9385 Bolts and four 3K-5234 Hard Washers . Adjust the position of the front track roller frame until the holes in the plates are in alignment with the mounting holes in the frames. The fabricated plates will keep the roller frames together if the front track roller frame breaks.
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| Illustration 8 | g00545455 |
Typical track roller frame of a large machine (D8L) (1) Fabricated plates on both sides | |
- Use a cutting torch to separate bearing sleeve (3) from the front track roller frame. Make a longitudinal cut on each side of the bearing in line with the tube. Remove the bearing in two sections. Inspect the front track roller frame for cracks at locations (K) and (L) .
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| Illustration 9 | g00545456 |
Typical front track roller frame of a large machine (D8L) (3) Bearing sleeve (K) Location to check for cracks (L) Location to check for cracks | |
- Weld four bolts (4) on the sides of the track roller frame. Position the bolts with threads outward according to Illustration 10. Use four nuts with four 3K-5234 Hard Washers to install one fabricated plate (1) on each side of the track roller frame. Adjust the position of the front track roller frame until the holes in the plates are in alignment with the bolts on the frames. The fabricated plates will keep the roller frame together if the front track roller frame breaks.
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| Illustration 10 | g00545521 |
Typical track roller frame of a medium machine (D7R) (1) Fabricated plates on both sides (4) Bolts are welded to the track roller frame. The plate is attached with hardened washers and nuts. | |
- Use a cutting torch to separate bearing sleeve (5) from the front track roller frame. Make a longitudinal cut on each side of the bearing in line with the tube. Remove the bearing in two sections. Inspect the front track roller frame for cracks at location (M) .
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| Illustration 11 | g00545522 |
Typical front track roller frame of a medium machine (D7R) (5) Bearing sleeve (M) Location to check for cracks | |
- Follow Steps 10 through 12 for large track-type machines. Follow Steps 13 through 15 for medium track-type machines.
- Cut a slot in the front track roller frame in order to expose the coils in the recoil spring. See Table 3 for dimensions.
| NOTICE |
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In this procedure, the coils in the recoil spring will be cut to release the preload. The first few coils of the spring will break before they are completely cut through. Some small particle may be thrown from the groove when a spring coil breaks. The breaking will result in a loud noise. The spring will move in the front track roller frame. |
Note: The radial position of the slot is not important. The slot can be on the top, on the inside, or on the outside.
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| Illustration 12 | g00545979 |
Typical front track roller frame of a large machine (D8L) See Table 3 for dimensions of the slot. | |
- Start at the front of the recoil spring and cut each coil separately until the preload in the recoil spring has been released.
- When the preload is released, the front track roller frame can be removed from the rear track roller frame. The front track roller frame can now be disassembled.
Show/hide table
Table 3 Dimensions of the Slot for the Release of the Preload in the Recoil Spring J N P Q D6H
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D6R
100 mm (3.9 inch)
75 mm (3.0 inch)
260 mm (10.2 inch)
60 mm (2.4 inch)D6H XL
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D6R XL
100 mm (3.9 inch)
75 mm (3.0 inch)
260 mm (10.2 inch)
240 mm (9.5 inch)D7H
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D7R
100 mm (3.9 inch)
75 mm (3.0 inch)
350 mm (13.8 inch)
60 mm (2.4 inch)D8L
100 mm (3.9 inch)
75 mm (3.0 inch)
593 mm (23.4 inch)
90 mm (3.5 inch)D8N
100 mm (3.9 inch)
75 mm (3.0 inch)
469 mm (18.5 inch)
90 mm (3.5 inch)D9L
100 mm (3.9 inch)
75 mm (3.0 inch)
738 mm (29.1 inch)
90 mm (3.5 inch)D9N/D9R
100 mm (3.9 inch)
75 mm (3.0 inch)
582 mm (22.9 inch)
90 mm (3.5 inch)D10
100 mm (3.9 inch)
75 mm (3.0 inch)
883 mm (34.7 inch)
90 mm (3.5 inch)D10N
100 mm (3.9 inch)
75 mm (3.0 inch)
743 mm (29.3 inch)
90 mm (3.5 inch)D10N
100 mm (3.9 inch)
75 mm (3.0 inch)
634 mm (25.0 inch)
90 mm (3.5 inch)D11N
100 mm (3.9 inch)
75 mm (3.0 inch)
939 mm (37.0 inch)
90 mm (3.5 inch)572R
100 mm (3.9 inch)
75 mm (3.0 inch)
350 mm (13.8 inch)
60 mm (2.4 inch)578
100 mm (3.9 inch)
75 mm (3.0 inch)
593 mm (23.4 inch)
90 mm (3.5 inch)589
100 mm (3.9 inch)
75 mm (3.0 inch)
738 mm (29.1 inch)
90 mm (3.5 inch)
- Cut a slot in the front track roller frame in order to expose the coils in the recoil spring. See Table 3 for dimensions.
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| Illustration 13 | g00545980 |
Typical front track roller frame of a medium machine (D7R) See Table 3 for dimensions of the slot. | |
- Start at the front of the recoil spring and cut each coil separately until the preload in the recoil spring has been released.
- When the preload is released, the front track roller frame can be removed from the rear track roller frame. The front track roller frame can now be disassembled.