C4.4 Engines for Caterpillar Built Machines Caterpillar

Specifications

Introduction

Note: If the crankshaft or the cylinder block are replaced, the piston height for all cylinders must be measured.

• New piston pin bearings must be bored after installation in the original connecting rods. Refer to "Piston Pin Bearings".

Piston Pin Bearings

Note: This procedure requires personnel with the correct training and the use of specialized equipment for machining.

Note: When the piston pin is installed, always install new retaining rings on each end of the piston pin. If the piston pin cannot be removed by hand, heat the piston to a temperature of 45° ± 5 °C (113° ± 9 °F) in order to aid the removal of the piston pin. Heating the piston to this temperature may also aid the installation of the piston pin.

If the piston pin bearing requires replacement but the original connecting rod is not replaced, the following procedures must be performed:

1. Determine the grade of length of the connecting rod. Use one of the following characteristics:
   • The mark

   • The color

   • Measuring the length

2. Remove the piston pin bearing from the connecting rod. Install a new bearing in the connecting rod. The new bearing is partially finished. The new bearing must be bored off-center to the correct diameter. This off-center position is determined by the grade of length of the connecting rod. Refer to table 1. The correct diameter of the bore in the piston pin bearing is given in Specifications, "Connecting Rod".

   Surface finish of the bored hole in the piston pin bearing ... Ra 0.8 micrometers

3. Machine the ends of the piston pin bearing to the correct length. Remove any sharp edges. Refer to Specifications, "Connecting Rod".

Table 1 references the following information: Grade of letter of the connecting rod, the color code of the connecting rod and the length of the connecting rod.