Before proceeding with the removal of the connecting rod and piston assemblies from the engine, it is necessary to remove the cylinder head, oil pan and oil pickup tube, bridge of the main bearing caps / oil baffle plate / balancing assembly (depending on configuration) (see Procedures for repairing SOHC gasoline engines without removing them from the vehicle, In-Vehicle DOHC Gasoline Engine Repair Procedures or Repair procedures for diesel engines 1.7 l and 2.0 l without removing them from the car).
1. Completely remove the stepped wear from the top of the cylinders using a special countersink - proceed in accordance with the manufacturer's instructions attached to the countersink. The step is formed at the boundary of the piston stroke, approximately 6.4 mm below the upper cut of the cylinder due to mechanical metal working and carbon formation, its presence can be determined by touch with a fingernail. Attempts to remove the connecting rod and piston assemblies without removing the stepped wear are fraught with damage to the pistons.
2. When you have finished preparing the cylinders, turn the engine upside down so that the crankshaft is on top.
3. Before removing the connecting rods from the crankshaft, evaluate the amount of axial play of their fit on the corresponding journals of the latter. Firmly insert the blade (I) measuring probe into the gap between the side wall of the lower head of the connecting rod and the cheek of the crank, completely selecting the play of the connecting rod on the shaft neck. The total thickness of the selected probe blades will be equal to the value of the axial play of the connecting rod. Compare the measurement result with the requirements (see Specifications). If the value of the axial play exceeds the maximum allowable value, this connecting rod must be replaced. The axial play of a new connecting rod, or an old one on a new shaft, may be less than the lower permissible limit, in which case the connecting rod can be machined - consult with car service specialists. Check all remaining connecting rods one by one.
4. Make sure that the lower heads of the connecting rods and their covers have identification marks belonging to your cylinder, if necessary, mark yourself with a small center punch or marker.
5. Turn the crankshaft so that the pistons of the 1st and 4th cylinders are in the BDC positions.
6. In several steps (1/2 turn per approach) loosen the nuts/bolts securing the cover of the lower head of the connecting rod of the first cylinder so that it is possible to unscrew them manually. Remove the connecting rod cover together with the bearing shell placed in it - try not to drop the latter.
On some engines, the cut of the lower head of the connecting rods is formed by breaking the workpiece while maintaining the shape of the fracture by special processing for better articulation. When removing caps from this type of connecting rod, be extremely careful not to damage the mating surfaces.
7. To protect the neck of the shaft and the mirror of the cylinder, pull on the studs of the lower head of the connecting rod a couple of pieces of a suitable size hose.
8. Remove the bearing shell from the connecting rod head, then, resting the wooden handle of the hammer against the bearing bed in the lower head, push the connecting rod and piston assembly out of the block through the top of the cylinder. If resistance occurs, immediately stop removing the assembly and make sure that the stepped wear on the top of the cylinder is completely removed.
9. In the same manner, remove the 4th cylinder connecting rod and piston assembly from the engine, then rotate the engine 180°clockwise and remove the 2nd and 3rd cylinder assemblies.
Proceed with extraction only after the connecting rod is located strictly parallel to the axis of the cylinder!
10. To avoid accidental mechanical damage to the bearings and loss of components, reinstall the bearing shells and secure the bearing caps to the lower heads of your connecting rods by hand-tightening the mounting bolts/nuts.
11. Do not remove pistons from connecting rods (see more details. Checking the condition of the components of the connecting rod and piston group).
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