Removal
1. Remove the engine (see the relevant chapter) and install it on the stand.
2. Remove the torsional vibration damping unit (see the relevant chapter).
3. Remove the cylinder head (see the relevant chapter).
4. Number the connecting rod bearing caps 2 and also mark the recesses 1 for oil supply (see illustration).
5. Unscrew the mounting bolts and remove the connecting rod caps.
6. Remove carbon deposits from the top of the cylinders and remove the corresponding piston together with the connecting rod.
7. Clean and inspect all parts. Replace them with new ones if necessary.
8. Mark the position of the piston rings. The piston ring locks are located at 120° relative to each other (see illustration).
9. Compress the rings with a special device, having previously lubricated them with engine oil, and insert the piston with the connecting rod into the cylinder bore.
Attention! Observe the installation position of the piston, focusing on the arrow on the piston bottom and hole 1 for oil outlet on the connecting rod (see illustration 12.8).
10. Tap the piston with the handle of a hammer until it is completely seated in the cylinder bore.
11. Install the connecting rod bearing caps, using the marks made before removal as a guide, screw in the new mounting bolts and tighten them to 35 Nm, followed by additional turns of 45° and 15°.
Piston rings - removal and installation
12. Remove the piston from the cylinder bore together with the connecting rod.
13. Remove the piston rings using pliers 1 (see illustration).
14. Clean the rings and their grooves on the piston. You can use the old ring to clean the grooves.
15. Check the gap in the piston ring lock using feeler gauges by inserting the rings into the gauge (see illustration).
16. Check the clearance between the piston rings and their grooves using feeler gauges (see illustration).
17. Install the piston rings into the grooves using pliers. The lower compression ring is installed so that the "TOP" inscription on it faces upwards.
18. Position the piston rings so that their locks are at 120° relative to each other (see illustration).
Piston - replacement
19. Remove the piston from the cylinder bore together with the connecting rod.
20. Before disassembling the piston and connecting rod, mark the position of the piston pin 2 in the head 5 of the connecting rod and in the piston hole 4. The connecting rod is installed in the piston so that its wall with the hole 6 for the oil outlet on it is facing away from the arrow 3 on the piston bottom (see illustration).
21. Remove thrust ring 1 from the piston pin using pointed pliers or another suitable tool and press out the pin (see illustration 12.20).
22. Lubricate the piston pin with engine oil and press it in by hand up to the thrust ring seat groove.
23. Lock the piston pin with thrust ring 1 and check the clearance I between the ends of the thrust ring. The clearance angle should not be more than 30° (see illustration).
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