Type 1 Engines and 9RM Engines
Note: For a complete description of Type 1 and Type 2 engines, refer to the Specifications Module, "Engine Design" for more information.
Illustration 1 | g00295602 |
Connecting Rod And Bearings |
(1) Inside diameter of rod for bearing ...
(2) Outside diameter of bearing for piston pin ...
Inside diameter of bearing for piston pin after reaming ...
Clearance between small end bearing and piston pin ...
(3) Distance between center of piston pin and center of crankshaft bearing ...
(4) Bearings are available for remachined journals of the crankshaft which have the following undersize dimensions:
Shell thickness ...
Width of connecting rod bearing ...
Bearing clearance ...
(5) Inside diameter of rod for bearing ...
(6) Connecting rod cap with nuts and bolts
Tighten the nuts for the connecting rod to the following torque: ...
Connecting rod cap with bolts only
Tighten the bolts for the connecting rod to the following torque: ...
(1) Inside diameter of rod for bearing ...
(2) Outside diameter of bearing for piston pin ...
Inside diameter of bearing for piston pin after reaming ...
Clearance between small end bearing and piston pin ...
(3) Distance between center of piston pin and center of crankshaft bearing ...
(4) Bearings are available for remachined journals of the crankshaft which have the following undersize dimensions:
Shell thickness ...
Width of connecting rod bearing ...
Bearing clearance ...
(5) Inside diameter of rod for bearing ...
(6) Connecting rod cap with nuts and bolts
Tighten the nuts for the connecting rod to the following torque: ...
Connecting rod cap with bolts only
Tighten the bolts for the connecting rod to the following torque: ...
Note: If piston cooling jets are installed, the piston and the connecting rod assembly must be turned when the piston and rod assembly are installed. Turning the piston and connecting rod assembly will prevent the connecting rod from hitting and damaging the piston cooling jet. When the connecting rod has passed the piston cooling jet, turn the connecting rod until the arrow or "Front" mark on the top of the piston is toward the front of the engine.
Type 2 Engines and 7BJ Engines
Note: For a complete description of Type 1 and Type 2 engines, refer to the Specifications Module, "Engine Design" for more information.
The piston height is controlled by the length of the connecting rod. Connecting rods are supplied in six grades of length. The different grades of length are manufactured by machining the hole in the piston pin bearing in an off-center position. The different grades of length are created by the following method:
- Machining the center of the hole in the piston pin
- Machining the center of the hole in the bearing
- If the connecting rod is replaced, ensure that the same grade of length as the original connecting rod is used.
However, if the crankshaft or the cylinder block is replaced, the required grade of length of the connecting rods may change.
A correct grade of length of a connecting rod can be ordered for replacement. The connecting rod includes the piston pin bearing. The piston pin bearing is machined in order to create the correct grade of length. The piston pin is installed in the connecting rod at the factory. Table 1 provides the specifications for the grade of length.
Note: The length of the connecting rod is determined by the following method: The bearing for the crankshaft journal must be removed and the piston pin must be installed. The original grade of length of the connecting rod is determined when the original piston pin is installed.
Connecting rods are color coded. The color code is a reference for the length (Y) of the connecting rod. Refer to Table 1 for the different lengths of connecting rods.
Illustration 2 | g00915056 |
Grade of Length | Color | Length of the Connecting Rod |
"F" | Red | |
"G" | Orange | |
"H" | White | |
"J" | Green | |
"K" | Purple | |
"L" | Blue | |
If a piston pin bearing requires replacement but the connecting rod does not require replacement, a new piston pin bearing can be ordered. This bearing is partially finished. The hole in the bearing must be machined off-center to the correct distance in order to create a connecting rod assembly that is the correct grade of length.
Refer to the Testing and Adjusting manual for the following procedures:
- Determine the length of the connecting rod.
- Determine the distortion of a connecting rod.
- Replace the piston pin bearing.
Serrated Connecting Rods and Flat Connecting Rods
Illustration 3 | g00295602 |
Connecting Rod And Bearings |
(1) Inside diameter of rod for bearing ...
(2) Outside diameter of bearing for piston pin ...
Inside diameter of bearing for piston pin after reaming ...
Clearance between small end bearing and piston pin ...
(3) Distance between center of piston pin and center of crankshaft bearing ...
(4) Bearing for connecting rod journal
Shell thickness ...
Width of connecting rod bearing ...
Bearing clearance ...
(5) Inside diameter of rod for bearing ...
(6) Connecting rod cap with nuts and bolts
Tighten the nuts for the connecting rod to the following torque: ...
Connecting rod cap with bolts only
Tighten the bolts for the connecting rod to the following torque: ...
Note: If piston cooling jets are installed, the piston and the connecting rod assembly must be turned when the piston and rod assembly are installed. Turning the piston and connecting rod assembly will prevent the connecting rod from hitting and damaging the piston cooling jet. When the connecting rod has passed the piston cooling jet, turn the connecting rod until the arrow or "Front" mark on top of the piston is toward the front of the engine.
Hydraulically Fractured Connecting Rods
Illustration 4 | g01064497 |
Note: The caps and rods must stay together as a pair.
Note: When the connecting rods are replaced, do not reuse the connecting rod bolts. New connecting rod bolts must be used.
The mating surfaces of the connecting rod are produced by hydraulically fracturing the forged connecting rod.
(7) Tighten the connecting rod bolts to the following torque. ...
Tighten the connecting rod bolts again to the following torque. ...
Tighten the connecting rod bolt for an additional 120 degrees.
(8) Connecting rod bearing
Illustration 5 | g01064498 |
(9) Diameter of the bore for the piston pin ...
(10) Distance between bearing centers ...
(11) Diameter for the bore for the connecting rod bearing ...