VALVE 4564599 - Caterpillar

Introduction
Do not perform any procedure in this Special Instruction until you read this information and you understand this information.Note: The fabricated tool can be used as an alternate method of tightening the fan drive belts.A fabricated tool has been designed to help tighten fan drive belts on 3500 engines. This tool is used with a standard hydraulic jack. The tool can be made with materials that can be procured locally.This Special Instruction provides the dimensions of the tool and an alternate procedure for tightening the fan drive belts.Dimensions of the Tool
Illustration 1 g01078660
(1) Flat steel 9.5 mm (0.375 inch) (2) Round steel tubing 38.1 mm (1.5 inch) by 2.4130 mm (0.095 inch)
Table 1
Dimensions for the Tool (1) (2)    
Callout     Dimension    
A    
9.5 mm (0.375 inch)    
B    
13.5 mm (0.5 inch)    
C    
76.2 mm (3 inch)    
D    
38.1 mm (1.5 inch)    
( 1 ) The radius of the bend is 99.
( 2 ) Dimensions are reference only.
Illustration 2 g01078661
Fabricated toolAlternate Procedure for Tightening Fan Drive Belts
Illustration 3 g01078663
Usage of the tool
Place the hydraulic jack and the tool onto the crankshaft hub.
Raise the jack until the tool contacts the fan drive hub.
Illustration 4 g01079231
Adjustment bolts for the fan drive
Loosen bolts (1) .
Raise the jack until the drive belts reach the correct belt tension.
Torque bolts (1) to 120 20 N m (89 15 lb ft).
Lower the jack.
Verify that the belt tension did not change.
Remove the jack and the tool.For applications that require multiple drive belts, replace the drive belts in matched sets. Replacing one drive belt of a matched set will cause the new drive belt to carry more load because the older drive belts are stretched. The additional load on the new drive belt could cause the new drive belt to fail.Refer to the Operation and Maintenance Manual for the service interval for the belts. Refer to the Specification Manual for the correct belt tension.