Pistons and Connecting Rod
REMOVAL
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 nuts and then remove the caps and the big end lower bearing.
2. Push each piston-connecting rod assembly toward the top of the cylinder.
Procedures for Removing and Installing Piston Pin
1. Use the special tools (09234-33001) disassemble and reassemble the piston and connecting rod.
2. Place the proper insert in the fork of the tool. Position the insert between the connecting rod and the piston.
3. Insert the proper removal tool through the hole in the arch of the tool.
CAUTION: Center the piston, rod and pin assembly with the removal arbor.
4. Press the piston pin out of the connecting rod.
5. Install the proper pin guide through the piston and into the connecting rod. Hand tap the pin guide into the piston for proper retention. Drop the piston pin into the other side of the piston.
CAUTION: The pin guide centers the connecting rod in the piston. When the piston, connecting rod, piston pin and pin guide assembly are positioned on the fork of the tool, the pin guide will also center this assembly in the tool. If a pin guide that is too small is used, the piston assembly will not be located centrally in the tool, and damage may occur to the fork and/or the insert of the tool.
6. Install piston assembly onto fork assembly of a tool. The tool will support connecting rod at the piston pin. Be sure that piston assembly is slid onto the fork until the pin guide contacts the fork insert.
7. Adjust the installing arbor to the proper length by turning the numbered sleeve on the lettered shaft until the specified alphanumeric setting from the application chart is obtained. Turn knurled nut to lock numbered sleeve on shaft.
8. Insert the installing arbor through the hole in the arch of the tool. Press piston pin into the connecting rod until the sleeve on the installing arbor contacts the top of the tool arch. The pin guide will fall out of the connecting rod as the piston pin is pressed in.
CAUTION: Do not exceed 1250 kgf of force when installing the arbor sleeve against the arch.
INSPECTION
Piston 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 a 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 - 0.08 mm (0.0016 - 0.0031 inch)
No.2 0.03 - 0.07 mm (0.0012 - 0.0028 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 to 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 dimension]
No.1 0.20 - 0.35 mm (0.0079 - 0.0138 inch)
No.2 0.37 - 0.52 mm (0.0146 - 0.0205 inch)
Oil ring side rail 0.20 - 0.7 mm (0.0079 - 0.0276 inch)
[Limit]
No.1, No.2 0.8 mm (0.031 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 lower part of cylinder that is less worn.
When replacing a ring, be sure to use a ring of the same size.
Piston ring service size and mark
STD: None
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 cylinder numbers put on the rod end cap at disassembly match.
When a new connecting rod is installed, make sure that the notches for holding the bearing in place are on the same side.
2. Replace the connecting rod it it is damaged on the thrust faces at either end, and also if it has a step wear in, or severely rough surface of, the inside diameter of the small end.
INSTALLATION
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 down firmly, and then press down on the portion which is to be inserted into the groove with a finger as illustrated.
CAUTION: Do not use a piston ring expander when installing side rail in order to protect side rail.
3. Install the lower side rail by the same procedure as Step 2.
4. Apply engine oil around the piston and piston rings.
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 neighboring gaps as possible. Make sure that the gaps are not positioned in the thrust and pin directions.
8. Hold piston rings firmly in 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.
CAUTION: Install the bearing with the oil hole in the block.
11. Install the thrust washers in the No.3 main bearing cap with the oil grooves facing outward.
12. 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.
13. When the connecting rod cap is installed, make sure that the cylinder numbers put on the rod and cap at disassembly match.
14. When a new connecting rod is installed, make sure that the notches for holding the bearing in place are on the same side.
15. When assembling, bolts should be fastened by plastic region angle-controlled method as following.
1) Apply oil to the thread of nuts and spot areas.
2) Tighten the connecting rod bolt.
Tightening torque
Connecting rod bolt 16 - 20 Nm (160 - 200 kg-cm, 11.6 - 14 ft. lbs.) + (90° - 94°)
CAUTION: After removing the connecting rod bolt, do not use bolt again.
16. Check the bearing clearance as follows:
1) Remove oil and dirt from the bearings and journals.
2) Cut plastic gauge to the same length as the width of the bearing and place it in parallel with the journal, avoiding the oil holes.
3) Install the bearing and cap. Tighten to the specified torque. During this operation, do NOT turn the crankshaft.
4) Remove the cap, measure the width of the plastic gauge at the widest part by using the scale printed on the plastic gauge package.
Connecting rod cap
Bearing clearance
Standard 0.018 - 0.036 mm (0.0007 - 0.0014 inch)
Limit 0.1 mm (0.0039 inch)
17. Check the connecting rod side clearance.
Side clearance 0.10 - 0.25 mm (0.0039 - 0.0098 inch)
Limit 0.4 mm (0.016 inch)