Removal and Replacement
Piston and Connecting Rod
Special tools, testers and auxiliary items required
• Guide Pins (8189)
Removing
- Disconnect and isolate the negative battery cable.
- Remove the oil pans, engine timing cover and cylinder heads. Refer to => [ Right Cylinder Head ] Right Cylinder Head and => [ Left Cylinder Head ] Left Cylinder Head.
- Remove the engine oil pump. Refer to => [ Oil Pump ] Oil Pump.
- Remove the eight main bearing cap bolts from the windage tray in the sequence shown and remove the windage tray (1).
- If necessary, remove the top ridge of the cylinder bores with a reliable ridge reamer before removing the pistons from the engine block. Be sure to keep the tops of pistons covered during this operation. Pistons and connecting rods must be removed from the top of the engine block. When removing piston and connecting rod assemblies from the engine, rotate the crankshaft CW so that each connecting rod is centered in the cylinder bore.
DO NOT use a number stamp or a punch to mark connecting rods or caps, as damage to connecting rods could occur
• Connecting rods and bearing caps are not interchangeable and should be marked before removing to ensure correct reassembly.
- Mark connecting rod and bearing cap positions (1) using a permanent ink marker or scribe tool.
• Typical V6 engine configuration shown.
Care must be taken not to damage the fractured rod and cap joint face surfaces, as engine damage may occur.
- Remove the connecting rod cap bolts (5) and the connecting rod cap (4). Discard the cap bolts.
- Remove the plastic guide plates (3) from the guide pins (8189) (7) and install the guide pins (8189) to the connecting rod being removed.
Care must be taken not to nick crankshaft journals, as engine damage may occur
- Remove the piston and connecting rod (1) from cylinder bore.
- Repeat the previous steps for each piston being removed.
- Immediately after piston and connecting rod removal, reinstall the bearing cap (4) on the mating connecting rod to prevent damage to the fractured cap and rod surfaces.
- If required, remove the piston rings. Refer to => [ Piston Rings ] Service and Repair.
- Repeat the previous steps for each piston being removed.
Installing
- If required, select and fit new piston and connecting rod assemblies to the engine block. Refer to => [ Piston Fitting ] Piston Fitting.
- If required, select and fit new bearings to the connecting rod. Refer to => [ Connecting Rod Bearing Fitting ] Procedures
- If required, hone the cylinder bores. Refer to => [ Cylinder Bore Honing ] Cylinder Bore Honing.
- If removed, install the piston rings. Refer to => [ Piston Rings ] Service and Repair.
- Position the piston ring end gaps as follows:
• Oil ring expander gap (5)
• Oil ring lower side rail end gap (4)
• Oil ring upper side rail end gap (1)
• No. 2 (intermediate) ring end gap (5)
• No. 1 (upper) ring end gap (2)
• Typical V6 engine configuration shown.
• Ensure the position of the ring end gaps does not change when installing the ring compressor.
- Lubricate the piston rings with clean engine oil. Position Piston Compressor (2) over the piston and rings. Tighten the compressor (2).
• Install the rod bearings in pairs. Do not mix sizes or use a new bearing half with an old bearing half.
- Install the bearing shell (8) on the connecting rod with the tang inserted into the machined groove in the rod. Lubricate the bearing surface with clean engine oil.
- Remove the plastic guide plates (3) from the guide pins (8189) (7) and install the guide pins (8189) to the connecting rod being installed.
• Right cylinder bank shown, left cylinder bank similar.
- The pistons crowns are stamped with a mark (1) indicating installation position. This mark must be positioned toward the front of engine on both cylinder banks.
- Wipe the cylinder bore clean and lubricate with clean engine oil.
- Rotate the crankshaft until the connecting rod journal is on the center of cylinder bore. Insert the piston and connecting rod into the cylinder bore and carefully position the guide pins over the crankshaft journal.
- Tap the piston down in the cylinder bore using a hammer handle while guiding the connecting rod into position over the rod journal.
• Typical V6 engine configuration shown.
The connecting rod bolts must not be reused. Always replace the connecting rod bolts whenever they are loosened or removed.
- Install the bearing shell (6) on the connecting rod cap (4) with the tang inserted into the machined groove in the cap. Lubricate the bearing surface with clean engine oil.
• Do not lubricate the threads of the connecting rod cap bolts (5).
- Install the connecting rod cap and bearing with the tang on the same side as the rod. Tighten the NEW connecting rod cap bolts (5) to 20 Nm (15 ft. lbs.) plus 90°.
- If required, check the connecting rod side clearance. Refer to => [ Measuring Connecting Rod Side Clearance ] Measuring Connecting Rod Side Clearance.
- Repeat the previous steps for each piston being installed.
The main bearing cap bolts are tightened using a torque plus angle procedure. The bolts must be examined BEFORE reuse. If the threads are necked down the bolts must be replaced.
- Check the main bearing cap bolts for necking by holding a scale or straight edge against the threads. If all the threads do not contact the scale (2) the bolt must be replaced.
- Install the windage tray with eight main bearing cap bolts. Tighten the bolts in the sequence shown to 21 Nm (16 ft. lbs.) plus 90°.
- Install the engine oil pump and oil pump pick-up. Refer to => [ Oil Pump ] Oil Pump.
- Install the cylinder heads. Refer to => [ Right Cylinder Head ] Right Cylinder Head and/or => [ Left Cylinder Head ] Left Cylinder Head.
- Install the engine timing cover and oil pans. Refer to => [ Lower Oil Pan ] Lower Oil Pan or => [ Upper Oil Pan ] Upper Oil Pan.
- If removed, install the oil filter and fill the engine crankcase with the proper oil to the correct level.
- Connect the negative battery cable. .
- Fill the cooling system. Refer to => [ Cooling System Draining and Filling ] Cooling System Draining and Filling.
- Operate the engine until it reaches normal operating temperature. Check cooling system for correct fluid level.