Rework Procedure for the Differential on 793 Off-Highway Trucks{3258} Caterpillar

Off-Highway Truck:

793D (S/N: FDB1-UP)

793C XQ (S/N: CBR1-UP)

793C (S/N: ATY1-UP)

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

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

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

793 (S/N: 4SJ1-UP)

Introduction

This Special Instruction provides the information that is necessary to rework the 232-1691 Differential Housing and the 232-1689 Differential Housing for the installation of the new thrust washer.

Do not perform any procedure that is outlined in this publication or do not order parts until you understand the information that is contained in this document.

Required Parts

1. Start by removing the differential and bevel gear.

   ReferenceSee Disassembly and Assembly, "Differential and Bevel Gear - Remove" for more information.

2. Disassemble the differential and bevel gear.

   ReferenceSee Disassembly and Assembly, "Differential and Bevel Gear - Disassemle" for more information.

Rework Procedure

Illustration 1	g01306901
232-1691 Differential Housing (1) Datum 01

Illustration 2	g01306907
275-7897 Differential Housing (2) 45 degree chamfer with a depth of 1.5 ± 0.25 mm (0.0591 ± 0.0098 inch) (3) Radius 0.5 ± 0.25 mm (0.0197 ± 0.0098 inch) (A) The diameter 170 mm (6.6929 inch) intersects the radius of the slot. (B) 120 degrees (C) 137.5 mm (5.4134 inch) from (1) Datum 01 to bottom of slot (D) Distance of 127 mm (5.0000 inch) from Datum 01 (1) to top of slot

1. Use a 21 mm (0.83 inch) end cutter with a 0.5 ± 0.25 mm (0.0197 ± 0.0098 inch) radius (3) in order to machine the slots to depth (C) 137.5 mm (5.4134 inch) from Datum 01 (1). A 1.5 ± 0.25 mm (0.0591 ± 0.0098 inch), 45 degree chamfer (2) between the counterbore face and the slot wall is required. Slots must be 120 degrees from each other. Slots must be offset from the current tapped holes in the radial direction so that none of the slots are machined into the current tapped holes for the old retaining screws. Refer to Illustration 2. 275-7897 Differential Housing will be machined from the 232-1691 Differential Housing . Refer to Illustration 1 in order to view the differential housing before the machining process.

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Illustration 3	g01307453
232-1689 Differential Housing Short Half.

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Illustration 4	g01307507
275-7898 Differential Housing Short Half. (4) Radius 0.5 ± 0.25 mm (0.0197 ± 0.0098 inch) (5) 45 degree chamfer with a depth of 1.5 ± 0.25 mm (0.0591 ± 0.0098 inch) (6) Datum 02 (E) 120 degrees (F) Diameter of170 mm (6.6929 inch) Diameter (F) intersects the radius of the slot. (G) Distance of 137.5 mm (5.4134 inch) from datum (2) to bottom of slot (H) Distance of 127 mm (5.0000 inch) from Datum 01 (1) to top of slot

2. Use a 21 mm (0.8268 inch) end cutter with a 0.5 ± 0.25 mm (0.0197 ± 0.0098 inch) radius (4) to machine the slots to depth (L) 137.5 mm (5.4134 inch) from Datum 02 (6). A 1.5 ± 0.25 mm (0.0591 ± 0.0098 inch) by 45 degree chamfer (5) between the face of the counterbore and the wall of the slot is required. Slots must be 120 degrees from each other. Slots must offset from the current tapped holes in the radial direction so that none of the slots are machined into the current tapped holes for the old retaining screws. Illustration 4 shows 275-7898 Differential Housing . The differential housing will be machined from the 232-1689 Differential Housing . Refer to Illustration 3 in order to view the differential housing before the machining process.

3. Assemble the differential and bevel gear.

   ReferenceSee Disassembly and Assembly, "Differential and Bevel Gear - Assemble" for more information.

4. Install the differential and bevel gear.

   ReferenceSee Disassembly and Assembly, "Differential and Bevel Gear - Install" for more information.