Field Installation Instructions for the 2-bolt to 3-bolt Fan Drive Upgrade on Certain 3500 Machines {1359, 7960} Caterpillar

Off-Highway Truck/Tractor

784B (S/N: 5RK1-UP)

784C (S/N: 2PZ1-UP)

785 (S/N: 8GB1-UP)

785B (S/N: 6HK1-UP)

785C (S/N: 1HW1-UP; APX1-UP)

785D (S/N: DMC1-UP; MSY1-UP)

789 (S/N: 9ZC1-UP)

789B (S/N: 7EK1-UP)

789C (S/N: 2BW1-UP)

789D (S/N: SPD1-UP)

793 (S/N: 3SJ1-UP)

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

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

Wheel Loader

994F (S/N: 4421-UP)

994H (S/N: DWC1-UP)

Introduction

This Special Instruction lists the steps required to install the 3-bolt fan drive on a 793C Off-Highway Truck with a non-variable speed fan drive. Other applications with a non-variable speed fan drive will be similar. This Special Instruction does not apply to applications using variable speed fan drives.

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

Required Parts

Rework Procedure

1. Drain the engine coolant into a suitable container for reuse or disposal.
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   Illustration 1	g03827808
   Typical 793C Off-Highway Truck

2. Using a suitable lifting device, remove the shunt tank and the engine covers as needed to improve access to the work area. The shunt tank weighs approximately 75 kg (165 lb) and the engine covers each weigh approximately 50 kg (110 lb).
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   Illustration 2	g03827809

3. Remove the fan guard(s) as needed to gain access to the fan.
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   Illustration 3	g03827810

4. Using a suitable lifting device, disconnect fan adapter from the fan hub, and move the supported fan and adapter forward slightly to simplify removal of the fan pulley and bracket assembly. The fan and adapter weigh approximately 160 kg (353 lb).
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   Illustration 4	g03827812

5. Disconnect fan drive belts.

6. Using a suitable lifting device, remove the fan pulley and fan drive bracket assembly from the engine area. The fan pulley and fan drive bracket assembly weigh approximately 110 kg (243 lb).

   Note: Some applications require replacement or modifications of the fan adapter and others do not. If required, the fan adapter can be removed from the fan once the bracket assembly is out of the engine area. Refer to "Adapter Identification" for more information.

7. Remove the fan pulley from the fan drive bracket assembly. The fan pulley weighs approximately 55 kg (121 lb).
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   Illustration 5	g03827815

8. On the bench, remove the bolts and retaining plate from the end of the shaft.

9. Remove the bearings, spacers, and fan hub.

10. Remove the shaft retaining bolt and washer from the rear of the bracket assembly.
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    Illustration 6	g03827816

11. Using proper support for the bracket, carefully position the bracket to press out the old shaft.
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    Illustration 7	g03827817
    (1) 1D-4624 Bolt or a suitable driver

12. Remove the old shaft using a suitable press with at least 40 ton capacity and suitable driver or a 1D-4624 Bolt (1).
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    Illustration 8	g06273541
    (2) 466-9948 Shaft

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    Illustration 9	g06273549
    The 466-9948 Shaft installed in the correct orientation.

13. Confirm the quality of the bore in the bracket before installing shaft (2).

14. Install the shaft so that one of the bolt holes is oriented in the 6 o'clock position and the remaining two are in a horizontal plane with the grease hole in the 12 o'clock position.

15. Secure the shaft in position with one 4E-9311 Bolt and one 5P-8248 Hard Washer.

    Note: Shaft and bracket base should be lubricated prior to pressing shaft into the bracket using a suitable press. Lowering the temperature of shaft (2) with dry ice or by storing the shaft in the freezer prior to assembly can facilitate shaft installation. Do not install the shaft by striking. Shaft deformation and bearing failure can result.

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    Illustration 10	g03827820
    (3) 6Y-7651 Bearing Cone (4) 6Y-7652 Bearing Cup (5) 1J-4034 Lip Type Seal

16. Install bearing cup (4), bearing cone (3), and lip seal (5) into the rear (engine-side) of the fan hub.
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    Illustration 11	g03827862
    (4) 6Y-7652 Bearing Cup

17. Install bearing cup (4) into the front (radiator-side) of the fan hub.
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    Illustration 12	g03827863

18. Install the fan hub onto the 466-9948 Shaft.

19. Install the 209-5296 Spacer and the 6Y-7651 Bearing Cone.
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    Illustration 13	g03827866
    (6) 1B-4367 Bolt (7) 5P-8247 Hard Washer (8) 466-9950 Washer

20. Install one washer (8) onto the 466-9948 Shaft with three bolts (6) and three washers (7).

    Torque bolts ... 215 N·m (159 lb ft)

    Note: Torque all bolts twice in a sequential pattern.

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    Illustration 14	g03827867

21. Turn the fan hub on the shaft to ensure freedom of motion. Fill the joint with grease and continue turning to ensure uniform grease distribution and continued freedom of motion.
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    Illustration 15	g03827870

22. Using a suitable lifting device, install the pulley onto the fan hub. The pulley weighs approximately 55 kg (121 lb).

    Torque bolts ... 47 N·m (35 lb ft)

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    Illustration 16	g03827919

23. Using a suitable lifting device, prepare to hoist the new bracket assembly and pulley into position. The new bracket assembly and pulley weigh approximately 110 kg (243 lb).
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    Illustration 17	g03827920

24. Carefully lower the new bracket assembly into position. Secure the new bracket assembly to the engine.
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    Illustration 18	g03827921

25. Install drive belts onto the pulley.

26. Secure fan adapter to the fan and the fan hub.

    Torque bolts ... 47 N·m (35 lb ft)

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    Illustration 19	g03827922

27. Install the fan guard(s).
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    Illustration 20	g03828371
    Typical 793C Off-Highway Truck

28. Using a suitable lifting device, reinstall the shunt tank and the engine covers. The shunt tank weighs approximately 75 kg (165 lb) and the engine covers each weigh approximately 50 kg (110 lb).

29. Fill the shunt tank with coolant. Refer to the Operation and Maintenance Manual for additional information.

Adapter Identification

Refer to "Adapter Rework" for the correct rework dimensions.

Adapter Rework

Illustration 21	g03891424
(1) 327-7990 Adapter (2) 471-1020 Adapter

If you have adapter (1), refer to Illustration 22 for the correct rework dimensions.

Illustration 22	g03891425
Dimensions of the 471-1020 Adapter (A) Radius 6 ± 0.5 mm (0.236 ± 0.020 inch) (B) Diameter 75 ± 0.5 mm (2.953 ± 0.020 inch) (C) 45.8 ± 0.5 mm (1.803 ± 0.020 inch)