Piston
DISASSEMBLY
CONNECTING ROD CAP
CAUTION: Keep the bearings in order with their corresponding connecting rods (according to cylinder numbers) for proper reassembly.
1. Remove the connecting rod cap bolts, then remove the caps and the big end lower bearing.
2. Push each piston connecting rod assembly toward the top of the cylinder.
DISASSEMBLY AND REASSEMBLY OF THE PISTON PIN
1. Using the special tools (09234-33001) and (0923433002), disassemble and reassemble the piston and connecting rod.
2. The piston pin is press fit into the rod little end, and the piston floats on the pin.
3. The tool consists of a support fixture with fork inserts, guides, adapters, an installer and a remover. The piston is supported in the support fixture while the pin is being installed or removed. Guides help position the pin as it is installed or removed, while the rod is supported by fork inserts.
4. To remove the pin from the piston, place the piston in the support fixture with the rod resting on the fork inserts. Pass the remove tool through the top of the support fixture and use it to press out the pin.
5. To install a new pin, the proper fork inserts must be in place to support the rod.
6. Position the rod inside the piston. Insert the proper pin guide through one side of the piston and through the rod. Hand tap the pin guide so it is held by the piston. Insert the new pin into the piston from the other side and set the assembly into the support fixture with the pin guide facing down.
NOTE: The pin guide should be centered on the connecting rod through the piston. If assembled correctly, the pin guide will sit exactly under the center of the hole in the tool's arch, and rest evenly on the fork inserts. if the wrong size pin guide is used, the piston and pin will not line up with the support fixture.
7. Insert the installer tool through the hole in the arch of the support fixture and use an hydraulic press to force the piston pin through the rod little end. Continue pressing until the pin guide falls free and the installer tool seats against the top of the arch.
CAUTION: Do not exceed 1250 - 500 kg (2765 - 1102 lb) of force when the Installing tool seats against the top of the arch.
INSPECTION
PISTONS AND PISTON PINS
1. Check each piston for scuffing, scoring, wear and other defects. Replace any piston that is defective.
2. Check each piston ring for breakage, damage and abnormal wear. Replace the defective rings. When the piston requires replacement, its rings should also be replaced.
3. Check that the piston pin fits in the piston pin hole. Replace any piston and pin assembly that is defective. The piston pin must be smoothly pressed by hand into the pin hole (at room temperature).
PISTON RINGS
1. Measure the piston ring side clearance. If the measured value exceeds the service limit, insert a new ring in the ring groove to measure the side clearance. If the clearance still exceeds the service limit, replace the piston and rings together. If it is less than the service limit, replace the piston rings only.
Piston ring side clearance
No.1: 0.04 - 0.085 mm (0.0016 - 0.0033 inch)
No.2: 0.04 - 0.085 mm (0.0016 - 0.0033 inch)
[Limit]
No.1 0.1 mm (0.004 inch)
No.2 0.1 mm (0.004 inch)
2. To measure the piston ring end gap, insert a piston ring into the cylinder bore. Position the ring at right angles in the cylinder wall by gently pressing it down with a piston. Measure the gap with a feeler gauge. If the gap exceeds the service limit, replace the piston ring.
Piston ring end gap [Standard dimensions]
No.1 0.20 - 0.35 mm (0.0079 - 0.0138 inch)
No.2 0.30 - 0.45 mm (0.0118 - 0.0177 inch)
Oil ring side rail 0.2 - 0.7 mm (0.0079 - 0.0276 inch)
[Limit]
No.1, No.2: 1.0 mm (0.039 inch)
Oil ring side rail: 1.0 mm (0.039 inch)
When replacing the ring without correcting the cylinder bore, check the gap with the ring situated at the low part of cylinder that is less worn out.
Piston ring service size and mark
0.25 mm (0.010 inch) O.S: 25
0.50 mm (0.020 inch) O.S: 50
0.75 mm (0.030 inch) O.S: 75
1.00 mm (0.039 inch) O.S: 100
NOTE: The mark can be found on the upper side of the ring next to the end.
CONNECTING RODS
1. When the connecting rod cap is installed, make sure that the cylinder numbers, marked on rod end cap at disassembly, match. When a new connecting rod is installed, make sure that the notches holding the bearing in place are on the same side.
2. Replace the connecting rod if it is damaged at either end of the thrust faces. If it has a stratified wear in, or if the surface of the inside diameter of the small end is severely rough, replace the rod.
REASSEMBLY
1 of 2
2 of 2
1. Install the spacer.
2. Install the upper side rail. To install the side rail, first put one end of the side rail between the piston ring groove and spacer, hold it firmly, and press down with a finger on the portion to be inserted into the groove (as illustrated).
CAUTION: Do not use a piston ring expander when installing side rail.
3. Install the lower side rail by the same procedure de scribed in Step 2.
4. Apply engine oil around the piston and piston grooves.
5. Using a piston ring expander, install the No.2 piston ring.
6. Install the No. 1 piston ring.
7. Position each piston ring end gap as far away from its neighboring gaps as possible. Make sure that the gaps are not positioned in the thrust and pin directions.
8. Hold the piston rings firmly with a piston ring compressor as they are inserted into cylinder.
9. Install the upper main bearings in the cylinder block.
10. Install the lower main bearings in the main bearing caps.
11. Make sure that the front mark of the piston and the front mark (identification mark) of the connecting rod are directed toward the front of the engine.
12. When a new connecting rod is installed, make sure that the notches for holding the bearing in place are on the same side.
13. When assembling, bolts should be fastened by the angle-torque controlled method as the following.
1. Apply oil to the thread of nuts and spot areas.
2. Tighten the connecting rod bolt.
Tightening torque
Connecting rod cap nut 32 - 35 Nm (320 - 350 kg.cm, 24 - 26 ft. lbs.)
CAUTION: After removing the connecting rod bolt, do not use it again. When using a new bolt, do not tighten the bolt more than 3 times.
14. Check the connecting rod side clearance.
Connecting rod side clearance
Standard: 0.10 - 0.25 mm (0.0039 - 0.0098 inch)
Limit: 0.4 mm (0.0157 inch)
15. Install the oil screen.
16. Install the oil pan
17. Install the cylinder head.