C3.3B Tier 4 Interim and EU Stage 3A Engines for Caterpillar Built Machines – Idler Gear – Remove and Install – C3.3B

Removal Procedure

Table 1
Required Tools    
Tool     Part Number     Part Description     Qty    
A     390-1135     Idler Gear Tool     1    

Start By:

  1. Remove the rear housing.

Note: Refer to Specification UENR0995 "Engine Design" for non-specified engine Torque Values.


Keep all parts clean from contaminants.

Contaminants may cause rapid wear and shortened component life.


Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.

Dispose of all fluids according to local regulations and mandates.

    Illustration 1g02795977

    Illustration 2g02795978

    Illustration 3g02795981

    Alignment of timing marks

  1. Ensure that Timing Marks (X) on the camshaft gear and the crankshaft gear are aligned. Refer to Illustration 1.

  1. Ensure that Timing Marks (Y) on the idler gear and the camshaft gear are aligned. Refer to Illustration 2.

  1. Ensure that Timing Marks (Z) on the idler gear and the fuel injection pump gear are aligned. Refer to Illustration 3.

    Illustration 4g02795984

  1. Remove bolts (2) , washer (3) , and the idler shaft from idler gear (1) . Remove idler gear (1) and the washer.

    Illustration 5g02795985

  1. Use Tooling (A) to remove idler gear bearing (4) from idler gear (1) .

Installation Procedure

  1. Install idler gear (1) in the reverse order of removal.

  1. Tighten bolts (2) to a torque of 30 to 34 N·m (22 to 25 lb ft).

    1. Ensure that the gears, cylinder block surface, and idler gear (1) are clean and free from wear or damage. If necessary, replace any components that are worn or damaged.

    1. Lubricate idler gear bearing surface (4) with clean engine oil.

    1. Check oil clearance between the idler gear shaft and the idler gear bushing.

    1. Check the idler gear shaft outer diameter and the inner diameter for the idler gear bushing.

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