Field Procedure to Install new Platform Assemblies on the 770 and 772 Off-Highway Trucks{1408, 1417, 1429, 7051, 7155, 7156, 7251, 7253, 7254, 7256, 7267, 7405, 7557} Caterpillar

Off-Highway Truck/Tractor:

770 (S/N: BZZ1-UP)

772 (S/N: RLB1-UP)

Introduction

ReferenceSpecial Instructions, REHS5504, "Rework Procedure for Headlight Wiring On Certain Off-Highway Trucks"

ReferenceDisassembly and Assembly, RENR8255, "770 and 772 Off-Highway Truck Engine Supplement", "Cowling (Radiator) Remove and Install"

This special instruction provides the information that is needed to update both platform assemblies to the current production configuration on the 770 and 772 Off-Highway Trucks. The instruction for the relocation of the headlamps on the front of the machines is also provided.

The new platform assemblies are narrower than the former platform assemblies. The new platform assemblies allow better approach angles on the machines during operation. The new position of the headlamps in the cowl assembly helps prevent damage to the headlamps during operation.

The rework procedure is adaptable to machines S/N:BZZ1-668, and ; S/N:RLB1-674. The new parts became effective in production with machines ; S/N:BZZ669-UP, and ; S/N:RLB675-UP.

Important Safety Information

Do not perform any procedure in this special instruction until you have read this special instruction and you understand this information. Use only proper tools and observe all precautions that pertain to the use of those tools. Failure to follow these procedures can result in personal injury. The following procedures should also be observed.

Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.

A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.

Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.

Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If the tools, the procedure, the work method, or your actions are not recommended by Caterpillar, ensure that the tools and your actions are safe for you and for others.

Ensure that the product will not be damaged or the product will be made unsafe by the operation, lubrication, maintenance, or the repair procedures.

Prepare the Machine for Maintenance

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Personal injury or death can result from machine movement. Place blocks in front of and behind the wheels to make sure the machine does not move while the parking brakes are disengaged.

1. Permit only one operator on the machine. Either keep other personnel away from the machine, or keep other personnel in the sight of the operator.

2. Move the machine to a smooth horizontal location. Move the machine away from any machines that are working and any personnel.

3. Move the transmission control to the PARK position.

4. Make sure that the transmission rotary selector spool is in the PARK position.

5. Activate the parking brakes. Stop the engine. Turn the battery disconnect switch to the OFF position.

6. Place blocks in front of the wheels and behind the wheels.

Required Parts

Rework Procedure

Removal and Installation of Support Assemblies

1. Before you begin the rework procedure for the platform assemblies, perform the updates specified in Special Instructions, REHS5504, "Rework Procedure for Headlight Wiring On Certain Off-Highway Trucks".

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Illustration 1	g02475440

2. Remove the 13 bolts (46) and 13 washers (47) that hold grill (48) in cowling assembly (49). Remove the grill from the cowling assembly. Save the bolts and washers. Discard the grill.

3. Remove cowling assembly (49) from the machine. Save the cowling assembly, and the hardware. For the proper procedure, refer to the above listed disassembly and assembly procedure.

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Illustration 2	g02475454

4. Remove the six bolts (50) and washers (51) from plate assembly (52) on the right side of the machine. Save the bolts, washers, and the plate assembly.

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Illustration 3	g02475456

5. Remove all of the parts from inside the right platform assembly. Save all of the parts.

6. Secure a lifting device that can lift 175 kg (386 lb) to the right platform group.

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Illustration 4	g02475460

7. Remove the six bolts (53) and hard washers (54) that hold the right platform group to the frame. Save the bolts and hard washers.

8. Remove the right platform group from the machine. Place the platform group in a position that allows you to work on the platform group.

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Illustration 5	g02475462

9. Remove the four bolts (55) and hard washers (56) that hold the 269-8710 Step Gp (57) to the right platform group. Remove plate (58) and plate (59) from the step group. Save the rest of the step group, the nuts, and bolts. Discard the two plates.

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Illustration 6	g02475463

10. Remove the eight bolts (64) and hard washers (65) that hold 276-3781 Handrail As (60) to the right platform group. Remove the handrail assembly from the platform group. Save the bolts and the hard washers. Discard the handrail assembly.

11. Remove the eight bolts (62) and hard washers (63 ) that hold 331-8158 Handrail As (61) to the right platform group. Remove the handrail assembly from the platform group. Save the bolts, and hard washers. Discard the handrail assembly.

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Illustration 7	g02475694

12. Position support assembly (1) in a location that allows you to work on the support assembly.

13. Use the eight bolts (62) and hard washers (63) that were saved in Step 11 to attach handrail assembly (2) to support assembly (1) .

14. Use the eight bolts (64) and hard washers (65) that were saved in Step 10 to attach one handrail assembly (3) to support assembly (1) .

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Illustration 8	g02475705

15. Use the nuts and bolts that were saved in Step 9 to attach one plate (4), and one plate (5) to step group (57). Attach plate (4) to the left side of the step group. Attach plate (5) to the right side of the plate group.

16. Use the four bolts (55) and hard washers (56) that were saved in Step 9 to attach step group (57) to support assembly (1) .

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Illustration 9	g02475710

17. Place one washer (6) each on four bolts (7). Use the four bolts and washers to attach step assembly (8) to support assembly (1) .

18. Secure a lifting device that can lift 175 kg (386 lb) to support assembly (1). Use the lifting device to position the support assembly to the machine.

19. Use the six bolts (53) and hard washers (54) that were saved in Step 7 to attach support assembly (1) to the machine.

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Illustration 10	g02475456

20. Install all of the parts inside support assembly (1) that were removed in Step 5.

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Illustration 11	g02475742

21. Use the six bolts (50) and six washers (51) that were saved in Step 4 to attach plate assembly (52) to the right side of the machine. Plate assembly (52) was also saved in Step 4.

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Illustration 12	g02475720

22. Install film (9), film (10), and film (11) to support assembly (1) as shown in Illustration 12.

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Illustration 13	g02475884

23. Remove the six bolts (66) and washers (67) that hold plate assembly (68) on the left side of the machine. Save the bolts, washers, and plate assembly.

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Illustration 14	g02475906

24. Remove all of the parts from inside the left platform group. Save all of the parts.

25. Secure a lifting device that can lift 175 kg (386 lb) to the left platform group.

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Illustration 15	g02475912

26. Remove the six bolts (69) and hard washers (70) that hold the left platform group to the machine. Save the bolts and hard washers.

27. Remove the left platform group from the machine. Place the platform group in a position that allows you to work on the platform group.

28. Remove latch (71) from the left platform group.

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Illustration 16	g02475918

29. Remove the four bolts (72) and hard washers (73) that hold the 269-8710 Step Gp (75) to the left platform group. Remove plate (74) and plate (76) from the step group. Save the step group, the nuts, and bolts. Discard the two plates.

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Illustration 17	g02475928

30. Remove the eight bolts (81) and hard washers (82) that hold handrail assembly (77) to the left platform group. Remove the handrail assembly from the platform group. Save the bolts and the hard washers. Discard the handrail assembly.

31. Remove the eight bolts (79) and hard washers (80) that hold handrail assembly (78) to the left platform group. Remove the handrail assembly from the platform group. Save the bolts, and hard washers. Discard the handrail assembly.

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Illustration 18	g02475931

32. Position support assembly (12) in a location that allows you to work on the support assembly.

33. Use the eight bolts (81) and hard washers (82) that were saved in Step 30 to attach one handrail assembly (3) to support assembly (12) .

34. Use the eight bolts (79) and hard washers (80) that were saved in Step 31 to attach handrail assembly (13) to support assembly (12) .

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Illustration 19	g02476059

35. Use the nuts and bolts that were saved in Step 29 to attach one plate (4), and one plate (5) to step group (75). Attach plate (4) to the left side of the step group. Attach plate (5) to the right side of the step group.

36. Use the four bolts (72) and hard washers (73) that were saved in Step 29 to attach step group (75) to support assembly (12) .

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Illustration 20	g02476068

37. Place one washer (6) each on four bolts (7). Use the four bolts to attach step assembly (8) to support assembly (12) .

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Illustration 21	g02476075

38. Install latch assembly (14), and latch cam (15) to support assembly (12) .

39. Secure a lifting device that can lift 175 kg (386 lb) to support assembly (12). Use the lifting device to position the support assembly to the machine.

40. Use the six bolts (69) and hard washers (70) that were saved in Step 26 to attach support assembly (12) to the machine.

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Illustration 22	g02475906

41. Install all of the parts inside support assembly (12) that were removed in Step 24.

42. Use the six bolts (66) and washers (67) to attach plate assembly (68) to the right side of the machine. All three items were saved in Step 23.

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Illustration 23	g02476197

43. Install film (16), film (17), film (18), and film (19) to support assembly (12) .

Fender Modification

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Illustration 24	g02506264
(A) 113.9 mm (4.48 inch) (B) 79.8 mm (3.14 inch) (C) 45.7 mm (1.80 inch) (D) 164.2 mm (6.47 inch) (E) 203.6 mm (8.02 inch) (F) Two holes at 223.2 mm (8.79 inch) (G) Three holes with a diameter of 4.3 mm (0.17 inch) (H) Diameter of 70.0 mm (2.76 inch) (J) 102 mm (4.0 inch)

1. For both fenders, use the dimensions in Illustration 24 to lay out the one hole (H) and three holes (G) for the marker lamp group. The right fender is shown. Reverse the image for the left fender.

2. Drill the four holes into each fender.

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Illustration 25	g02476659

3. Assemble one lockwasher (20) each three screws (21) .

4. Use three screws (21) to install one marker lamp group (22) into the left fender. Use three screws (21) to install one marker lamp group (22) into the right fender.

Handrail Modification

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Illustration 26	g02476745

1. On the left side of the machine, remove nut (83), spacer (84), two hard washers (85), bolt (86), and horn assembly (87). Save the nut, hard washers, and the horn assembly. Discard the spacer and the bolt.

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Illustration 27	g02476781
(A) 86.4 mm (3.40 inch) (B) 70.5 mm (2.78 inch) (C) 102.2 mm (4.02 inch) (D) 134.0 mm (5.28 inch) (E) Three holes with a diameter of 9.0 mm (0.35 inch) (F) 121.4 mm (4.78 inch)

2. For both sides, use the dimensions in Illustration 27 to lay out the three new holes for the signal lamp group. Drill the three new holes in both sides of the machine. The plate is part of the support assembly in the handrail group. The support assembly is on the outside of the machine.

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Illustration 28	g02476864

3. Place one hard washer (23) on each bolt (24). Use the bolts to attach plate assembly (25) to the plate on the support assembly.

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Illustration 29	g02476890

4. Use three hard washers (23), and three nuts (26) to attach one signal lamp group (27) to plate assembly (25) .

5. Install grommet (28) to the plate on the support assembly.

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Illustration 30	g02476917

6. On the right side of the machine, remove nut (88), spacer (89), two hard washers (90), bolt (91), and horn assembly (92). Save the nut, hard washers, and the horn assembly. Discard the spacer and the bolt.

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Illustration 31	g02476928

7. For the right side, use the dimensions in Illustration 27 to lay out the new holes on the plate for the signal lamp group. Drill the three new holes in the plate. The plate is part of the support assembly in the handrail group.

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Illustration 32	g02476940

8. Use three hard washers (23), and three nuts (26) to attach one signal lamp group (27) to the plate on the support assembly.

9. Install grommet (28) to the plate assembly.

Updating the Harness Assemblies

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Illustration 33	g02476956

1. Remove the former 272-8409 Wiring Harness (93) from the right side of the machine.

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Illustration 34	g02476979

2. Install the new lighting harness assembly (29) on the right side of the machine.

   Note: Due to the location of breakouts, feed the new lighting harness assembly from the engine compartment outward.

3. Remove the former 272-8408 Lighting Harness As from the left side of the machine.

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Illustration 35	g02476987

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Illustration 36	g02476994

4. Install the new lighting harness assembly (30) on the left side of the machine.

   Note: Due to the location of breakouts, feed the new wiring harness from the engine compartment outward.

5. Move cowling assembly (49), the bolts (46), and washers (47) to an area that allows you to work on the cowling assembly. The cowling assembly, bolts, and washers were removed in Step 2, and Step 3 in ""Removal and Installation of Support Assemblies" ".

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Illustration 37	g02477016
Inside view of the cowling assembly

6. Use the bolts (46) and washers (47) from Step 2 to install grill assembly (31) into cowling assembly (49) .

7. Install flood lamp group (32) in the outside position on both openings in grill assembly (31) .

8. Install flood lamp group (33) in the inside position on both openings in grill assembly (31) .

9. Use one bolt (34), nut (88), and two hard washers (90) to attach one clip (35), and horn assembly (92) to the grill assembly (31). Nut (88), and two hard washers (90), and horn assembly (92) were removed in Step 6 in ""Handrail Modification" ".

10. Use one bolt (34), nut (83), and two hard washers (85) to attach one clip (35), and horn assembly (87) to the grill assembly (31). Nut (83), and two hard washers (85), and horn assembly (87) were removed in Step 1 in ""Handrail Modification" ".

11. Install bracket (36) under the top bolt on the door in cowling assembly (49) .

12. Use one bolt (34), two hard washers (37), and one nut (38) to attach clip (39) to bracket (36) .

13. Install lighting harness assembly (40) to the lights that are mounted to the grill assembly.

14. Attach one cable strap (41) to each link, and clip that is attached to the grill assembly.

15. Install cowling assembly (49) on the machine.

16. Connect the harnesses in the cowling assembly to the harnesses on the machine.

Updates to the Visibility Arrangement (If Equipped)

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Illustration 38	g02478029

1. Remove the four bolts (94), four nuts (95) and eight hard washers (96), four clips (97), and the tube assembly (98) from both sides of the machine. Save the convex mirror (99) that is attached to both tube assemblies (98). Discard the other parts.

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Illustration 39	g02478054

2. Use six clips (42), six washers (43), three bolts (44), and three nuts (38) to attach each tube assembly (45) to the left handrail assembly and the right handrail assembly.

3. Attach one convex mirror (99) to each tube assembly (45). The convex mirror was saved in Step 1.