General Information
In general, various types of connecting rod bearings have been used in B series engines:
• Bi-Metal overlays
• Tri-Metal overlays
• Narrowed bearings (for some naturally aspirated engines).
Reference the appropriate part information resources when replacing the connecting rod bearings so the correct
connecting rod bearings are installed.
Preparatory Steps
• Disconnect the batteries. Refer to the OEM instructions.
• Drain the lubricating oil. Refer to Procedure 007-037 in Section 7.
• Remove the oil pan and oil pan gasket. Refer to Procedure 007-025 in Section 7.
• Remove the lubricating oil suction tube. Refer to Procedure 007-035 in Section 7.
• Remove the block stiffener plate. Refer to Procedure 001-089 in Section 1.
• Remove, as needed, the J-jet piston cooling nozzles. Refer to Procedure 001-046 in Section 1.
Remove
NOTE: The cylinder head does not need to be removed if the connecting rod bearings are being inspected or replaced.
Use the barring tool, Part Number 3824591, to bar the engine over to bottom dead center of the connecting rod bearing to be removed.
Mark each connecting rod and cap to identify cylinder location.
Remove and install only one connecting rod cap at a time to avoid mismatching connecting rods with the wrong
connecting rod cap.
Remove the connecting rod bolts and connecting rod cap.
Remove the lower end bearing.
Mark the cylinder number and the letter “L” (lower) on the flat surface of the bearing tang.
Some engines are equipped with an external Torx”‘ head.
NOTE: Slight bending of the J-jet piston cooling nozzles can result in severe engine damage. Replace piston
cooling nozzles if any are bent or damaged during assembly or disassembly.
Remove the J-jet piston cooling nozzle for each cylinder that the connecting rod bearings will be removed. Refer to
Procedure 001-046 in Section 1.
Push the connecting rod into the cylinder, away from the crankshaft, to allow the upper bearing shell to be removed.
Mark the connecting rod bearings for position and cylinder number as they are removed.
Example: U1 – upper rod bearing for cylinder number 1.
Wash the bearing and connecting rod caps.
Dry with compressed air.
Inspect the connecting rod caps, connecting rod bearing saddles and capscrews for nicks, cracks, burrs, scratches, or fretting.
Inspect the bearings for damage.
Replace any bearings with the following damage:
• Pitting
• Flaking
• Corrosion
• Lock tang damage
• Scratches.
Inspect the bearing shell seating surface for nicks or burrs.
If nicks or burrs can not be removed with an abrasive pad, Part Number 3823258 or equivalent, the bearings must
be replaced.
NOTE: If bearings are damaged they must be replaced as a set.
NOTE: For more detailed information of bearing damage, see Analysis and Prevention of Bearing Failures, Bulletin
3810387.
Measure the rod bearing shell thickness with an outside micrometer that has a ball tip.
Discard a bearing shell if its thickness is below the minimum specification .
Connecting rod bearings are identified with a part number and size stamped on the back side.
Determine the size of the removed rod bearing and obtain a set of the same size.
Oversize service rod bearings are available for use with crankshafts that have been machined undersized. See the
appropriate parts catalog.
Check the rod bearing journals for damage or excessive wear. Minor scratches are acceptable.
Install
Used connecting rod bearings must be installed in their original locations.
To reduce the possibility of engine damage, make sure that the backside of the bearing, and connecting rod
surface that the bearing contacts, is clean and dry.
Install the upper bearings in the connecting rod. Make sure that the tang is aligned.
Install the lower bearings in the connecting rod caps.
Make sure the tang is aligned.
NOTE: For engines equipped with fracture split connecting rods, the upper and lower connecting rod
bearing are not interchangeable.
NOTE: For engines equipped with fracture split connecting rods, the fracture split surface on the
connecting rod and connecting rod cap must be kept dry and clean to ensure proper mating of the two surfaces.
Lubricate the bearing surfaces with Assembly Lube, Part Number 3163087 or equivalent.
Lubricate the connecting rod bolt threads and under the heads with clean 15W-40 oil.
When installing the connecting rod cap, the numbers stamped on the connecting rod cap and connecting rod
must match and be on the same side of the connecting rod, to prevent engine damage during engine operation.
Install the connecting rod caps on the corresponding connecting rod.
Install and hand-tighten the connecting rod capscrews.
NOTE: The long end of the connecting rod must be on the exhaust side of the engine.
Tighten the connecting rod capscrews.
Alternately tighten the two capscrews.
After tightening the capscrew for each connecting rod, rotate the crankshaft 360 degrees to make sure the
crankshaft rotates freely.
