793C Off-Highway Truck/Tractor Power Train Caterpillar

Removal Procedure

Start By:

1. Install the truck body retaining cable. Refer to Disassembly and Assembly, "Truck Body Retaining Cable - Remove and Install".

2. Remove the front drive shaft guard. Refer to Disassembly and Assembly, "Drive Shaft Guard (Front) - Remove and Install".

3. Remove the rear drive shaft guard. Refer to Disassembly and Assembly, "Drive Shaft Guard (Rear) - Remove and Install".

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The space between the body and the frame becomes a zero clearance area when the body is lowered. Failure to install the retaining cable can result in injury or death to personnel working in this area.

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Illustration 1	g00508312

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Illustration 2	g00508313

1. Use a lifting sling and a suitable hoist to support the weight of drive shaft (2). The drive shaft weighs approximately 169 kg (372.6 lb).

2. Remove four bolts (1).

3. Use a suitable lever to compress the drive shaft.

4. Remove four bolts (3) and spider (4). Spider (4) weighs approximately 20 kg (44.1 lb).

5. Install blocking in the center tube to support the drive shaft. Remove the hoist.
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   Illustration 3	g00508315

6. Use a lifting sling and a suitable hoist to support the weight of the drive shaft.

7. Remove four bolts (5).
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   Illustration 4	g00508336

8. Use a suitable lever to separate the transmission yoke from spider (6).

9. Remove four bolts (7) and spider (6).
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   Illustration 5	g00509422

10. Support the drive shaft. Pull the drive shaft toward the rear of the machine. When the drive shaft is clear of the center tube, remove the drive shaft from the truck.

Installation Procedure

1. Inspect the universal joints and mating yokes for damage to the key, keyway, threaded holes, and pilot diameter. Replace any damaged items.

2. Clean the mating surface of the yoke assembly and universal assembly including threaded holes of wax, grease, paint, dirt, or debris. Clean the mating surface of the slip joint of wax, grease, paint, dirt, or debris.

3. Ensure that the universal joints are fully seated prior to tightening the bolts by either seating with a rubber or wooden hammer, or the use of run down bolts in an X pattern. Replace the run down bolts after use.
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   Illustration 6	g00509422

4. Use a lifting sling and a suitable hoist to support the weight of the drive shaft. Insert the drive shaft into the truck. Push the drive shaft toward the front of the truck.
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   Illustration 7	g00508336

5. Install spider (6) and four bolts (7).

   Note: During the installation of the drive shaft, use new bolts (7). Tighten the bolts to a torque of 550 ± 20 N·m (405.7 ± 14.8 lb ft). Do not reuse the bolts.

6. Connect the transmission yoke to spider (6).
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   Illustration 8	g00508315

7. Install four bolts (5).

   Note: During the installation of the drive shaft, use new bolts (5). Tighten the bolts to a torque of 550 ± 20 N·m (405.7 ± 14.8 lb ft). Do not reuse the bolts.

8. Install blocking the center tube to support the drive shaft. Remove the hoist.

9. Perform a static bolt check 550 ± 20 N·m (405.7 ± 14.8 lb ft) 250 hours after the drive shaft has been installed in the machine.
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   Illustration 9	g00508312

10. Use a lifting sling and a suitable hoist to support the weight of the drive shaft.

11. Install spider (4) and four bolts (3). Spider (4) weighs approximately 20 kg (44.1 lb).

    Note: During the installation of the drive shaft, use new bolts (4). Tighten the bolts to a torque of 550 ± 20 N·m (405.7 ± 14.8 lb ft). Do not reuse the bolts.

12. Perform a static bolt check 550 ± 20 N·m (405.7 ± 14.8 lb ft) 250 hours after the drive shaft is installed in the machine.
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    Illustration 10	g00508313

13. Extend drive shaft (2).

14. Install four bolts (1).

    Note: During the installation of the drive shaft, use new bolts (1). Tighten the bolts to a torque of 550 ± 20 N·m (405.7 ± 14.8 lb ft). Do not reuse the bolts.

15. Perform a static bolt check 550 ± 20 N·m (405.7 ± 14.8 lb ft) 250 hours after the drive shaft is installed in the machine.

16. Remove the lifting sling.

End By:

1. Install the front drive shaft guard. Refer to Disassembly and Assembly, "Drive Shaft Guard (Front) - Remove and Install".

2. Install the rear drive shaft guard. Refer to Disassembly and Assembly, "Drive Shaft Guard (Rear) - Remove and Install".

3. Remove the truck body retaining cable. Refer to Disassembly and Assembly, "Truck Body Retaining Cable - Remove and Install".