Procedure to Modify the Canopy and Body Assembly for 793A, 793B, and 793C Off-Highway Trucks{7258} Caterpillar

Off-Highway Truck:

793 (S/N: 3SJ1-UP)

793B (S/N: 1HL1-UP)

793C (S/N: 4AR1-UP; ATY1-UP; 4GZ1-UP)

793D (S/N: FDB1-UP)

Introduction

The body and canopy assemblies for 793A, 793B, and 793C Off-Highway Trucks can be modified in order to fit the chassis of 793D Off-Highway Trucks. This Special Instruction includes a procedure to modify the body and canopy assemblies.

In order to fit the body and canopy assemblies on the 793D, the following procedures will need to be performed:

• Modification of an exhaust beam in the body and canopy assembly for the 793D exhaust pipe group

• The addition of a boss for the rotary position sensor for the body

References

Reference Special Instruction, REHS1841, "General Welding Procedures"

Procedure to Modify the Body and Canopy Assemblies

Illustration 1	g01257139
Canopy and Body Assembly (D1) 263.0 mm (10.35 inch) (D2) 383.0 mm (15.08 inch) (D3) 97.0 mm (3.82 inch) (D4) 10.0 ± 2 mm (0.39 ± 0.08 inch) (W1) 6.0 mm (0.24 inch) fillet weld with 1.5 mm (0.06 inch) penetration

1. Cut a rectangular exhaust hole in the exhaust beam. Refer to Illustration 1.

2. Weld Plate (1) in the exhaust hole that was cut in Step 1. Refer to Illustration 1.

3. Install Cover (2), Washers (3), and Bolts (4) to the underside of the exhaust beam at the location of the previously used exhaust hole.

Installation of the 9R-9866 Boss for the Rotary Position Sensor for the Body

Illustration 2	g01257424
View of the inside left plate assembly (D5) 21.0 ± 2.0 mm (0.83 ± 0.08 inch) (D6) 165.0 ± 2.0 mm (6.50 ± 0.08 inch) (W2) 3.0 mm (0.12 inch) fillet weld

1. Weld Boss (5) to the plate assembly. Refer to Illustration 2.

   Note: The additional boss is necessary for 793D machines that are equipped with a rotary position sensor for the body.