Assembly Procedure for the Performance Plus Body{7258} Caterpillar

Off-Highway Truck:

793C (S/N: CBR1-UP; ATY1-UP)

Introduction

ThisSpecial Instruction contains the necessary procedures and information for the assembly and welding of the Performance Plus Body for the 793C Off-Highway Truck.

The shipping configuration of the 793COff-Highway Truck body is dependent upon the destination and the type of the transportation that is available. In some instances, a varying (degree) of completion on the truck body will already be assembled. This can shorten the assembly of the truck body. The following Special Instruction illustrates the complete assembly of the truck body. Nothing will be assumed to have been assembled previously.

Note: Do not perform any procedures that are outlined in this publication or order any parts until you have read this publication thoroughly.

The suggested tools and equipment should be readily available at the site for the assembly. If the part and equipment are not available the assembly will be more difficult and more time will be necessary to complete the assembly.

The assembly procedure is completed in the right side up position. The body assemblies are then welded. The remaining welding and assembly is then completed.

Note: The serial number of the truck body is stamped on the edge of each section.

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

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Make sure the lifting cables and other lifting devices are strong enough to support the machine.

A flat, smooth, well drained area 25 m (80 ft) by 30 m (100 ft) is needed for the assembly.

Weights

Two mobile cranes will be needed for the assembly of the truck body. The cranes will need to have a total lifting capacity of 31780 kg (70063 lb). See Weights.

The weights that are listed are approximate.

Parts List

Truck Dimensions

Required Tools

This is a list of tools that are needed to assemble the body.

Illustration 1	g01010440
View of the wedges and angles

Fabricate a number of wedges and angles prior to the assembly of the body. The angle should be made from a minimum of 12 mm (0.50 inch) mild steel. The wedge should be made from a minimum of 20 mm (0.8 inch) mild steel. Table 7 and Illustration 1 gives the dimensions that will be used to make the angles and wedges.

Weld Tolerance and Parameters

Note: Personal breathing protection should be worn by the welders. Personal breathing protection will prevent fumes from entering the lungs of the person that is welding. Use a 1U-8088 Type H Respirator for respiratory protection.

All of the welders must be qualified in Shielded Metal Arc Welding (SMAW) and Flux Cored Arc Welding (FCAW). All of the welders must be qualified in groove welding and fillet welding in the vertical position. Refer to the American National Standards Institute (ANSI)/American Welding Society (AWS) D1.1. Prior to welding, the process must have been used by the welders during the last six months. Welding qualifications must be documented and welding qualifications must be current.

The surrounding area must be a minimum temperature of 16 °C (60 °F) before welding and during welding.

The proper stick welding electrode for Shielded Metal Arc Welding (SMAW) is E7018 American National Standards Institute (ANSI)/American Welding Society (AWS) A5.5. The finished weld will have the following minimum mechanical properties:

• 500 MPa (72519 psi) Tensile Strength

• 420 MPa (60916 psi) Yield Strength

• 22 percent elongation in 50 mm (2 inch)

• 27 N·m (20 lb ft) at −29 °C (−20 °F) Notch Toughness

The E7018 electrodes must be stored in an electrode oven at 121 °C (250 °F). Scrap the E7018 electrodes or recondition the E7018 electrodes if the E7018 electrodes get damp. Recondition the E7018 electrodes to the manufacturer's specifications. The following table is the electrode's current settings in relation to the electrode's diameters:

Set the polarity to direct electrode positive (reverse polarity). Use the direct current. Remove the slag after every weld pass. The width of the weld should not exceed two times the electrode diameter.

As an alternative process, use the Flux Cored Arc Welding (FCAW) with E71T-1 H8 (ANSI/A5.20) welding electrode and the manufacturer's shielding gases that are specified. The weld that is deposited by the flux cored welding electrode will have the following minimum mechanical properties:

• 500 MPa (72519 psi) Tensile Strength

• 420 MPa (60916 psi) Yield Strength

• 22 percent elongation in 50 mm (2 inch)

• 27 N·m (20 lb ft) at −18 °C (0 °F) Notch Toughness

Use only flux cored welding electrodes that have been stored in undamaged packages that resist moisture or use only flux cored welding electrodes that have been stored in an oven at 120 °C (250 °F).

Welding parameters will vary due to the welding position and due to the manufacturer of the welding electrode. A 1.3 mm (0.051 inch) electrode diameter will typically have the following welding parameters:

Note: Use the manufacturer's recommended welding electrode parameter.

Set the polarity to direct electrode positive (reverse polarity). Use the direct current. Remove the slag after every weld pass. The width of the weld should not exceed 8.0 mm (0.32 inch) for a fillet weld.

Note: The weld that uses gas shielded wire requires protection from the wind and water. The truck body should be covered with a tarp if there is rain or high wind.

Refer to Special Instruction, REHS1841, "General Welding Procedures" for additional welding instructions.

Specifications for Cables, Chains, and Lifting Devices

Use approved cables, chains, and lifting devices in order to lift components. Refer to the manufacturer's weight's in order to determine the application when you select the following items: cable, chain and lifting devices. When you lift a component, the lift angle is critical. Refer to the Illustration that follows in order to see the effect of the lift angle on the working load limit.

Note: The lifting devices that are shown in this publication are not Caterpillar parts.

Illustration 2	g00629745
Lift angles for lifting slings. (A) The load capacity is 100% of the working load limit for the sling. (B) The load capacity is 86% of the working load limit for the sling. (C) The load capacity is 70% of the working load limit for the sling. (D) The load capacity is 50% of the working load limit for the sling.

Lifting Procedure

Note: For handling purposes, the lifting eyes are located at convenient spots on each module. Use these lifting eyes only. Once the module is welded in position the lifting eyes may be removed. After the removal of the lifting eyes, grind the area smooth. Remove only the lifting eyes that will interfere with ordinary assembly or an operation procedure.

Assembly Procedure

Procedure for Installation of the Body

Note: Remove any paint, rust, scale, slag, dirt, moisture, tape, etc from any weld areas.

Note: The assembly procedure starts with the body in the right side up position. The weight of the center body assembly is 8680 kg (19136 lb).

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Illustration 3	g01205711
The center body assembly (2) in the right side up position.

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Illustration 4	g01205756
View of center body assembly (2) that is cleaned

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Illustration 5	g01205734
View of the edges that are cleaned

1. Use a grinder in order to clean the welding areas of center body assembly (2). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding. Refer to Illustration 4 and Illustration 5.

   Note: All of the welding areas on center body assembly (2) should now be cleaned.

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Illustration 6	g01206101
View of the plastic liner block that is removed

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Illustration 7	g01206115

2. Remove the plastic liner blocks along the weld seams on the right and left sides.

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Illustration 8	g01206065

3. Use a grinder in order to clean the welding areas of left body assembly (3). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

   Note: All of the welding areas on left body assembly (3) should now be cleaned.

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Illustration 9	g01206130

4. Remove the plastic liner blocks along the weld seam.

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Illustration 10	g01205923

5. Use a suitable crane and use a suitable lifting device in order to lift the left body assembly (3). The weight of the left body assembly is 4532 kg (9991 lb).

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Illustration 11	g01205938
Position the two sides together.

6. Position the left body assembly (3) next to center body assembly (2) .

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Illustration 12	g01206095
The center and left side are ready to be placed together.

7. Move left body assembly (3) into position next to center body assembly (2) .

8. If necessary, trim the joints in order to ensure a correct fit. A slight chamfer or a radius on the edge of the backup strip may help assembly.

   Note: Align the front wall first. Work down the radius to the floor. Install bolts to secure alignment. Work along the floor from the front to the back.

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Illustration 13	g01206140
Install the bolts and nuts.

9. Install the ten nuts (5) and bolts (6) onto center body assembly (2) and left body assembly (3) in order to correctly position the body. Do not tighten the bolts and nuts.

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Illustration 14	g01206200
View of nuts (5) and a view of bolts (6) that are installed

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Illustration 15	g01206190
View of the angles and wedges that can be used along the inside of the front wall and used along the floor seam for alignment of the body assemblies

10. Use angles and wedges to help align the left body assembly (3) to the center body assembly (2) .

    Note: Before tack welding any angles to the body assembly, use a grinder in order to clean the welding areas. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

11. If a section of the front wall or floor is warped, a welded angle and a wedge can be used to help align the seam.

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Illustration 16	g01228251
Wedge and angle

Note: Refer to Table 7 for the correct weld. Install the wedge from the welded side of the angle.

Note: Only weld the angle on one side.

Note: Refer to Illustration 1 and Table 7 for dimensions in order to fabricate the angles and wedges.

12. The angles and wedges can be used throughout the welding process in order to align the weld seams. Use as many angles and wedges as required. Remember to grind the tack welds smooth before painting.

13. After alignment, tack weld the body assemblies in position. Angles may be removed and angles may be reused.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 17	g01206192
View of the hydraulic jack that is used on the body assembly

14. Each side can be adjusted with a different hydraulic jack. Also, 1U-9204 Lever Puller Hoist can be used to help slide the body assemblies together.

    Note: Before tack welding any hydraulic jacks to the body assembly, use a grinder in order to clean the welding areas. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 18	g01206187
View of nut (5) and of bolt (6) that is tightened

15. Tighten the ten nuts (5) and bolts (6) until center body assembly (2) and left body assembly (3) is in alignment.

16. Adjust the hydraulic jacks during the assembly procedure, if necessary.

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Illustration 19	g01206198
View of the left body assembly and center body assembly that is tack welded

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Illustration 20	g01206197
An Outside view of the left body assembly and center body assembly that has been tack welded.

17. Completely tack weld seams on the front wall and the outside wall before finish welding the seams.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 21	g01207201

18. Use a grinder in order to clean the welding areas of right body assembly (4). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: All of the welding areas on right body assembly (4) should now be cleaned.

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Illustration 22	g01206194

19. Use a suitable crane and use a suitable lifting device in order to lift the right body assembly (4). The weight of the right body assembly is 4531 kg (9989 lb).

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Illustration 23	g01207325
Position the two sides together.

20. Position the right body assembly (4) next to center body assembly (2) .

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Illustration 24	g01207332
The center and right side are ready to be placed together.

21. Slide right body assembly (4) into position next to center body assembly (2) .

22. If necessary, trim the joints in order to ensure a correct fit. A slight chamfer or a radius on the edge of the backup strip may help assembly.

    Note: Align the front wall first. Work down the radius to the floor. Install bolts to secure alignment. Work along the floor from the front to the back.

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Illustration 25	g01207327
Install the nuts and bolts.

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Illustration 26	g01207336
View of nut (5) and of bolt (6) that is installed

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Illustration 27	g01207486
View of nut (5) and of bolt (6) that is tightened

23. Install the ten nuts (5) and bolts (6) onto center body assembly (2) and right body assembly (4) in order to correctly position the body. Do not tighten the bolts and nuts.

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Illustration 28	g01226452

24. Use angles and wedges to help align the right body assembly (4) to the center body assembly (2) .

    Note: Before tack welding any angles to the body assembly, use a grinder in order to clean the welding areas. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 29	g01226547

25. Each side can be adjusted with a different hydraulic jack. Also, 1U-9204 Lever Puller Hoist can be used to help slide the body assemblies together.

    Note: Before tack welding any hydraulic jacks to the body assembly, use a grinder in order to clean the welding areas. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 30	g01207491
Outside view of right body assembly (4) and center body assembly (2) that has been tack welded.

26. Completely tack weld seams on the front wall and the outside wall before finish welding the seams.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 31	g01207494
Preparing the canopy assembly for welding

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Illustration 32	g01207666
View of the canopy assembly that has been cleaned

27. Use a grinder in order to clean the weld areas of canopy assembly (1). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: The canopy rock guard (7) can be installed on canopy assembly (1) while canopy assembly (1) is on the ground or after canopy assembly (1) is installed on the body.

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Illustration 33	g01210578
Canopy rock guards (7) .

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Illustration 34	g01210577

28. Use a grinder in order to clean the welding areas of canopy rock guard (7). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 35	g01210581
Positioning the rock guard for welding

29. Use a suitable lifting device in order to lift the canopy rock guard (7). The weight of the canopy rock guard is 73 kg (161 lb). Position canopy rock guard (7) onto the side of the canopy assembly (1) .

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Illustration 36	g01210566
View of the installed canopy rock guard

30. Once the canopy rock guard is aligned, tack weld the canopy rock guard to the canopy assembly.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 37	g01232158
An Illustration of the welds that are for the installed canopy rock guards.

31. Weld rock guard (7) to canopy assembly (1) .

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 38	g01210576

32. Repeat the same procedure for rock guard (7) on the other side of canopy assembly (1) .

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Illustration 39	g01207670
View of the canopy assembly that is cleaned

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Illustration 40	g01207668
View of the body assembly that is cleaned

33. Use a grinder in order to clean the welding areas of the canopy assembly and body assembly. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 41	g01208029
View of the notches that are cut out on the welded strong back plate on canopy assembly (1)

34. Cut out notches on the welded strong back plate on canopy assembly (1). The notches should align with the lugs in order to align the canopy assembly to the body assembly.

    Note: The procedure is necessary only when a welded strong back plate is in the position that is shown on canopy assembly (1) .

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Illustration 42	g01207671

35. Attach a suitable lifting device to canopy assembly (1). The weight of the canopy assembly and the canopy rock guards is 3566 kg (7862 lb).

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Illustration 43	g01207673
This is a view of positioning the canopy assembly to the body.

36. Use a suitable crane and a suitable lifting device in order to lift canopy assembly (1) into position.

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Illustration 44	g01208037

37. Check for a good fit on the corner.

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Illustration 45	g01208038

38. Align the lugs that are attached to the canopy assembly. Use nut (5) and bolt (6) to aid in the alignment procedure and to secure canopy assembly to the body assembly.

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Illustration 46	g01208039
View of an angle and wedge that can be used for alignment of the canopy assembly to the body assembly

39. Use angles and wedges to help align the canopy assembly to the front wall of the body assembly.

    Note: Before tack welding any angles, bolts, or lugs to the body assembly, use a grinder in order to clean the welding areas. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 47	g01208040
View of the side wall that is being aligned to the canopy assembly

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Illustration 48	g01208042
View of the front wall that is being aligned to the canopy assembly

40. Each side can be adjusted with a different hydraulic jack. Also, 1U-9204 Lever Puller Hoist can be used to help slide the canopy assembly and the body assemblies together.

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Illustration 49	g01208180
Tack welding the canopy assembly to the body assembly

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Illustration 50	g01210573
View of the outside canopy assembly and body assembly that is preheated for welding

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Illustration 51	g01208177
Outside of the canopy assembly and the body assembly that is tack welded.

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Illustration 52	g01208172
View of the right side of the canopy assembly

41. Once the canopy assembly is aligned, tack weld the canopy assembly to the front wall and to the side walls.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 53	g01217412
View of the canopy assembly that is welded to the side wall of the body assembly

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Illustration 54	g01232156
Illustration of the weld for the canopy assembly and the outside side wall of the body assembly (N1) Weld both sides.

42. Weld the canopy assembly to the side wall and to the front wall of the body assembly.

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

    Note: Remove the slag after every weld pass.

43. Repeat Steps 41 and 42 for the other side.

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Illustration 55	g01216591

44. Use a grinder in order to clean the welding areas of the canopy rock guards on both sides of the canopy assembly. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 56	g01216588
View of the edge on the canopy rock guard that is cleaned

45. Use a grinder in order to clean the welding areas of canopy rock guards (10). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 57	g01216592

46. Attach a suitable lifting device in order to position canopy rock guard (7) for welding. The weight of the canopy rock guard is 73 kg (161 lb).

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Illustration 58	g01216594
View of the installed rock guards

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Illustration 59	g01232160
Welds that are for the installed canopy rock guards. (N1) 13 places (N2) two places

47. Weld canopy rock guard (7) to the bottom of the canopy assembly and the body assembly.

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

48. Repeat the same procedure for canopy rock guard (7) on the other side of canopy assembly (1) .

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Illustration 60	g01230562
View of the seam that is welded on canopy assembly (1)

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Illustration 61	g01226874
View of canopy assembly (1) that is welded to the body assembly

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Illustration 62	g01226877
View of the weld seam that connects canopy assembly (1) to the body assembly

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Illustration 63	g01234764
Illustration of the welds that are for the canopy and body assembly (N1) E - F

49. Weld the seams that connect the canopy assembly (1) to the body assembly.

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 64	g01226781
View of left body assembly (3) that is welded to center body assembly (2)

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Illustration 65	g01226854
View of the weld seam that is located on the floor that connects the left body assembly (3) and center assembly (2) .

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Illustration 66	g01234779
Illustration of the welds that are located on the floor of the body assemblies (N1) A to B and C to D

50. Weld the seam on the floor and the seam on the wall that connects the left body assembly (3) to the center body assembly (2) .

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

    Note: Remove the slag after every weld pass.

51. Repeat Step 50 for the right body assembly.

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Illustration 67	g01226916
View of right body assembly (4) that is welded to center body assembly (2)

52. Weld the seam on the floor and the seam on the front wall that connects right body assembly (4) and center body assembly (2) .

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

    Note: Remove the slag after every weld pass.

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Illustration 68	g01226843

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Illustration 69	g01226881

53. Remove all nuts, bolts, lugs, wedges, and angles. Grind the welds smooth on the inside floor and walls of the body assemblies.

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Illustration 70	g01226849
View of the outside canopy assembly and the outside body assembly that is cleaned

54. Use a grinder in order to clean the welding areas of the outside canopy assembly (1) and the outside body assembly. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 71	g01226909
View of outside canopy assembly (1) that is welded to the outside body assembly

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Illustration 72	g01234925
Illustration of the outside weld that is located on the wall of the canopy and body assembly (N1) E-F

55. Weld the outside seam of the wall that connects the canopy assembly (1) to the body assembly.

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

    Note: Remove the slag after every weld pass.

56. Use a grinder in order to clean the welding areas of the outside left body assembly (3) and the outside center body assembly (2). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 73	g01226910
Outside left body assembly (3) that is welded to the outside center body assembly (2) .

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Illustration 74	g01231073
Illustration of the welds that are located on the outside wall of the body assemblies

57. Weld the seam that connects the left body assembly (3) to the center body assembly (2) .

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

    Note: Remove the slag after every weld pass.

58. Before you finish weld, remove the bolts, nuts, clamps, and angles.

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Illustration 75	g01216156
View of the plates (8) that are being prepared for welding

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Illustration 76	g01207724
View of the outside of the center body assembly that is being cleaned for welding

59. Use a grinder in order to clean the welding area of the body assembly and plate (8). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 77	g01210570
View of the plate (8) that is being aligned for welding

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Illustration 78	g01210567
View of the plate that is welded

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Illustration 79	g01234789
Illustration of the welds for the plate that is installed on the outside of the body assembly

60. Weld plate (8) to the outside of the body assembly.

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 80	g01216158

61. Repeat Step 59 and 60 for the other side.

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Illustration 81	g01216160
View of plate (9) and plate (10) that is being cleaned for welding.

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Illustration 82	g01216243

62. Use a grinder in order to clean the welding area of the body assembly and plate (9) and plate (10). Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

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Illustration 83	g01216161
View of a lug that is used to align plate

63. The plate (9) can be aligned by the use of a lug.

    Note: Before tack welding any lugs to the body assembly, use a grinder in order to clean the welding areas. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 84	g01216245

64. Position plate (9) for welding.

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Illustration 85	g01216246

65. Once the plate is aligned, tack weld the plate (9) to the outside wall of the center body assembly.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 86	g01216247

66. Tack weld a metal strip to plate (10) .

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Illustration 87	g01216248

67. Use angles and wedges to help align the plate (9) and plate (10) to the outside wall of the center assembly.

    Note: Before tack welding any angles to the body assembly, use a grinder in order to clean the welding areas. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 88	g01216249
View of plate (10) that is preheated

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Illustration 89	g01216251

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Illustration 90	g01234903
Illustration of the welds for the plates that are installed on the outside of the body assembly (N1) Weld the four plates in eight places. (N2) Weld the four plates in six places.

68. Weld plate (9) and plate (10) to the outside of the body assembly.

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 91	g01216253

69. Repeat Step 62 through 68 for the other side.

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Illustration 92	g01216255

70. Position a suitable crane in order to lift the body assembly onto wood blocks. The weight of the body assembly is 21609 kg (47640 lb).

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Illustration 93	g01216586

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Illustration 94	g01216725

71. Slowly lower both cranes (A) and (B) and position the body onto the wood blocks.

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Illustration 95	g01216721
View of the canopy assembly that is cleaned

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Illustration 96	g01216723
Body down indicator (14) that is tack welded.

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Illustration 97	g01217014

72. Once body down indicator (15) is aligned, tack weld the body down indicator to the canopy assembly.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 98	g01235512
Illustration of the welds for the body down indicator that is installed on the canopy assembly

73. Weld the body down indicator (15) to canopy assembly (1) .

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 99	g01217009
View of the edge that is located on the bottom of the body that is cleaned

74. Use a grinder in order to clean the welding areas of the bottom of the body assembly. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

    Note: All of the welding areas on the bottom of the body assembly should now be cleaned.

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Illustration 100	g01226918

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Illustration 101	g01234919
Illustration of the welds for the floor seams on the bottom of the body assembly

75. Weld the bottom floor seam that connects the left body assembly (3) to the center body assembly (2) .

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

    Note: Remove the slag after every weld pass.

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Illustration 102	g01230818
View of the left side that is preheated for welding

76. Repeat Step 74 through 75 for the other side.

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Illustration 103	g01217013
View of the rail (11) that is cleaned

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Illustration 104	g01230825
View of the edges that are cleaned on the left hand side of the body assembly

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Illustration 105	g01217012
View of a hydraulic jack that is used to align the rail to the body assembly

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Illustration 106	g01234931
Illustration of welds for the rails that are installed on the bottom of the body assembly

77. Weld rail (11) to the left side of the body assembly.

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

78. Repeat Step 77 for rail (12) for the right hand side of the body assembly.

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Illustration 107	g01217137
View of the outside of the body assembly that is being cleaned for welding

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Illustration 108	g01217141
View of the deflector plate (13) that is cleaned

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Illustration 109	g01217143
Plate (13) that is tack welded.

79. Once the deflector plate is aligned, tack weld deflector plate (13) to the outside wall of the body assembly.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 110	g01217147
View of deflector plate (14) that is cleaned

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Illustration 111	g01217148
Deflector plate (14) that is tack welded.

80. Once the deflector plate is aligned, tack weld deflector plate (14) to the outside wall of the body assembly.

    Note: Before tack welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

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Illustration 112	g01235191
Illustration of the welds for the deflector plates that are installed on the bottom of the body assembly

81. Weld deflector plates (13) and (14) to the body.

    Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

82. Repeat the same procedure for deflector plate (13) and deflector plate (14) on the other side of the body assembly.

Installation of the Liner Group

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Illustration 113	g01231071
View of seam on the body assembly that is cleaned for the installation of the support plates

1. Use a grinder in order to clean the welding areas of the seam on the body assembly. Completely remove all paint, rust, scale, slag, dirt, moisture, tape, etc before welding.

   Note: All of the welding areas on seams of the body assembly should now be cleaned.

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Illustration 114	g01231075
View of the support plates that are cut to length

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Illustration 115	g01231078
View of the support plates that are cleaned

2. Cut the support plates (1) and support plates (2) to the proper length. Use a grinder in order to clean the plates.

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Illustration 116	g01232157

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Illustration 117	g01232161
View of the support plates that are welded onto the body assembly

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Illustration 118	g01235644
Illustration of the welds for the support plates that are welded to the floor of the body assembly (N1) Weld both ends in 68 places. (N2) Weld both ends in four places.

3. Weld plates (1) and plates (2) to the body.

   Note: Before welding, preheat the welding areas to the proper temperature. Refer to ""Welding Materials" ". Use 164-3310 Infrared Thermometer in order to check for the proper preheat temperature.

4. Reinstall the plastic liner blocks.

5. Remove all of the lifting eyes and the brackets that were installed temporarily on the body and canopy assembly.

6. Clean the body completely and paint the body completely.

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Illustration 119	g01235547
View of the completed canopy and body assembly

7. Install decals on the front and sides of the canopy and body assembly.

8. Refer to Special Instruction, "Assembly Procedure For the 793C Off-Highway Truck" for installation of the body to the truck.

Welding Materials

The following welding materials are used in order to fabricate the MSD II truck body:

• 400 Brinell Hardness Number Material

• 450 Brinell Hardness Number Material

Before welding on the MSD II truck body, verify the materials that are used in order to fabricate your particular MSD II truck body. There are specific welding procedures for each material. Refer to the following procedures in order to successfully weld the materials during the assembly of the truck body.

Note: When two or more materials need to be welded together, use the procedure for the material that has the more stringent requirements.

400 Brinell Hardness Number Material

The following procedure covers the requirements for welding the assembly of the MSD II truck bodies that are fabricated with 400 Brinell Hardness Number Material. Refer to ""Weld Tolerance and Parameters" " for qualifications, safety, and welding electrode parameters. Attach the welding ground cable directly to the body assembly. Protect all of the machined areas from sparks and spatter that are produced by welding, chipping, and grinding operations.

Proper preparation of the welding area must be conducted prior to welding. All weld joints and welding areas must be exceptionally clean. Clean the welding area with a grinder. Completely remove all paint, rust, scale, slag, dirt, moisture, grease, etc before welding.

Tight fitup of the body assemblies is very important. Ensure that every effort is made in order to minimize the gap spacing. Minimizing the gap spacing reduces the residual stresses.

In order to minimize the possibility of cracking, use large tack welds. The tack welds should have a maximum width of 8 mm (0.32 inch) and a length of 75 mm (3 inch).

The surrounding area must be a minimum temperature of 16 °C (60 °F) before welding and during welding.

Preheat is most critical during the tack welding procedure and during the welding of the root pass. Preheat is not necessary when the weld joints have a combined thickness of less than 40 mm (1.6 inch) and when the ambient temperature is a minimum of 16 °C (60 °F). When the combined thickness of the weld joints is greater than 40 mm (1.6 inch), use the following preheat temperatures:

Ensure that the weld groove and 76 mm (3 inch) in each direction from the weld groove is preheated to the specified temperature. Verify the preheat temperature with 164-3310 Infrared Thermometer or with a temperature stick.

The minimum interpass temperature should equal the preheat temperature. The maximum interpass temperature should not exceed 250 °C (480 °F).

Note: The above preheat and interpass temperatures are for mild restaint to moderate restraint. If clamping devices are utilized in order to reduce the gap spacing to less than 3 mm (0.12 inch), use the next higher preheat temperature, when possible. Additional stresses are offset by the use of the next higher preheat temperature.

All welded areas need to be inspected. Hydrogen induced cracking normally occurs within 72 hours of welding. Allow the welded areas to cool for 48 hours to 72 hours prior to performing a visual inspection. If any welding areas are suspected of being cracked during the visual inspection, then use the dye penetrant process or the magnetic particle inspection process in order to inspect the welding areas. The welds shall be free from the following defects: cracks, porosity, undercut and incomplete fusion. All weld quality shall conform to American National Standards Institute (ANSI)/American Welding Society (AWS) D14.3.

450 Brinell Hardness Number Material

The following procedure covers the requirements for welding the assembly of the MSD II truck bodies that are fabricated with 450 Brinell Hardness Number material. Refer to ""Weld Tolerance and Parameters" " for qualifications, safety, and welding electrode parameters. Attach the welding ground cable directly to the body assembly. Protect all of the machined areas from sparks and spatter that are produced by welding, chipping, and grinding operations.

Proper preparation of the welding area must be conducted prior to welding. All weld joints and welding areas must be exceptionally clean. Clean the welding area with a grinder. Completely remove all paint, rust, scale, slag, dirt, moisture, grease, etc before welding.

Tight fitup of the body assemblies is very important. Ensure that every effort is made in order to minimize the gap spacing. Minimizing the gap spacing reduces the residual stresses.

In order to minimize the possibility of cracking, use large tack welds. The tack welds should have a maximum width of 8 mm (0.32 inch) and a length of 75 mm (3 inch).

The surrounding area must be a minimum temperature of 16 °C (60 °F) before welding and during welding.

Preheat is most critical during the tack welding procedure and during the welding of the root pass. Preheat is not necessary when the weld joints have a combined thickness of less than 40 mm (1.6 inch) and when the ambient temperature is a minimum of 16 °C (60 °F). When the combined thickness of the weld joints is greater than 40 mm (1.6 inch), use the following preheat temperatures:

Ensure that the weld groove and 76 mm (3 inch) in each direction from the weld groove is preheated to the specified temperature. Verify the preheat temperature with 164-3310 Infrared Thermometer or with a temperature stick.

The minimum interpass temperature should equal the preheat temperature. The maximum interpass temperature should not exceed 250 °C (480 °F).

Note: The above preheat and interpass temperatures are for mild restaint to moderate restraint. If clamping devices are utilized in order to reduce the gap spacing to less than 3 mm (0.12 inch), use the next higher preheat temperature, when possible. Additional stresses are offset by the use of the next higher preheat temperature.

All welded areas need to be inspected. Hydrogen induced cracking normally occurs within 72 hours of welding. Allow the welded areas to cool for 48 hours to 72 hours prior to performing a visual inspection. If any welding areas are suspected of being cracked during the visual inspection, then use the dye penetrant process or the magnetic particle inspection process in order to inspect the welding areas. The welds shall be free from the following defects: cracks, porosity, undercut and incomplete fusion. All weld quality shall conform to American National Standards Institute (ANSI)/American Welding Society (AWS) D14.3.