Each connecting rod is made of forged steel and has a precision-machined bronze bushing in its piston pin bore (refer to Figure 2-16). The crankpin bore of each connecting rod is split and holds a two-piece sleeve bearing insert. Studs and nuts retain the rod caps.
Each connecting rod is carefully balanced, and no repair procedures (such as straightening, bushing replacement or crankpin bore enlargement) are allowed. Clearance between the piston pin and connecting rod bushing must not exceed 0.030 mm (0.0012 in.).
Connecting rods are fitted to pistons so that the bearing tang slots of both the rod and its matched cap face away from the camshaft. During engine manufacture, a combination of two bearing insert sizes is used at each of the eight connecting rod bores and is based on crankpin journal measurements (refer to Figure 2-17).
For service purposes, bearing size combinations provide an oil clearance of 0.045 to 0.100 mm (0.0018 to 0.0039 inch), as measured with the plastigage procedure.
Two sizes of crankpin bearing inserts are available for service:
• Standard (yellow color identification)
• 0.026mm (0.001 in.) U.S. (green color identification)