Piston and Connecting Rod
PISTON AND CONNECTING RODREMOVAL AND INSTALLATION
Removal Steps 1-12:
Required Special Tools:
^ MIT216941: Piston Pin Setting Tool
^ MB992010: Bolt Guide
REMOVAL SERVICE POINTS
[A] CONNECTING ROD CAP REMOVAL
1. Mark the cylinder number on the side of the connecting rod big end for correct reassembly.
2. Keep the removed connecting rods, caps, and bearings in that order according to the cylinder number.
[B] PISTON AND CONNECTING ROD ASSEMBLY REMOVAL
1. Not to damage the crank pin, attach a special tool MB992010, to the connecting rod bolt.
2. Remove the piston and connecting rod assembly from the cylinder block.
[C] PISTON PIN REMOVAL
1. Remove the stop screw from the base.
2. Select the correct piston support for your application (See above). Fit the piston support onto the base. Place the base on press support blocks.
3. Insert the press pin through the piston pin hole. Select the correct connecting rod guide pin (See above). Thread the guide pin onto the threaded portion of the press pin.
4. Position the piston assembly on the piston support in the press. With the press pin up as shown, insert the guide pin through the hole in the piston and through the hole in the piston support.
CAUTION
To avoid piston damage, the piston support must seat squarely against the piston. Verify that the piston pin will slide through the hole in the piston support.
5. Press the piston pin out of the assembly.
6. Remove the piston pin from the press pin.
INSTALLATION SERVICE POINTS
[A] PISTON PIN INSTALLATION
1. When replacing the piston, read off the cylinder bore size mark on the cylinder block as illustrated, and select a piston according to the following table.
2. Thread the stop screw and lock nut assembly into the base. Fit the correct piston support on top of the base. Insert the press pin, threaded end up, into the hole in the piston support until the press pin touches the stop screw.
3. Using the markings on the press pin, adjust the stop screw to the depth shown on the instruction for special tool MIT216941.
4. Place the base on press support blocks.
5. Slide the piston pin over the threaded end of the press pin, and thread the correct guide pin up against it.
6. Coat the piston pin with engine oil. With the connecting rod held in position, slide the guide pin through the piston and connecting rod.
7. Press the piston pin through the connecting rod until the guide pin contacts the stop screw.
CAUTION
Due to production tolerance variations, it is necessary to visually inspect the piston pin depth after installation to verify that the piston pin is centered. Adjust if necessary.
8. Remove the piston assembly from the base. Remove the guide pin and press pin from the assembly.
9. Check that the piston moves smoothly.
[B] OIL RING INSTALLATION
1. Fit the oil ring spacer into the piston ring groove.
CAUTION
Do not use a piston ring expander when installing the side rail.
2. Install the upper side rail.
To install the side rail, first fit one end of the rail into the piston groove, then press the remaining portion into position by hand. See illustration.
NOTE: The side rails and spacer may be installed in either direction.
NOTE: New spacers and side rails are colored for identification of their sizes.
3. Install the lower side rail in the same manner as described in step 2.
4. Make sure that the side rails move smoothly in both directions.
[C] PISTON RING NUMBER 2 / PISTON RING NUMBER 1 INSTALLATION
1. Using the piston ring expander, fit number 2 into the number 2 groove of piston.
NOTE: Install piston rings with identification mark facing up, to the piston crown side.
2. Install the number 1 piston ring in the same manner as step 1.
Identification mark:
Number 1 ring: 1R
Number 2 ring: 2R
NOTE: Confirm the profile for Number 1 and Number 2 piston rings carefully. Install them correctly by paying careful attention to the direction of the top and bottom.
NOTE: The identification mark and the size mark are stamped on the upper plane of the piston ring (piston top side).
3. To prevent incorrect installation, check the identification mark of each piston ring. The identification mark is stamped near the ring gap.
[D] CONNECTING ROD BEARING INSTALLATION
1. Measure the crankshaft pin diameter and confirm its classification from the following table. On a crankshaft supplied as a service part, identification marks of its pins are stamped at the positions shown in the illustration.
2. If the crankshaft pin outside diameter identification mark is "I," for example, select a bearing whose identification color is "Black"
If there is no identification color paint on the crankshaft, measure the pin outside diameter and select a bearing appropriate for the measured value.
3. Install the selected bearing in the big end and in the cap of the connecting rod.
[E] PISTON AND CONNECTING ROD INSTALLATION
1. Apply engine oil to the circumference of the piston, piston rings, and oil ring.
2. Arrange the piston ring and oil ring gaps (side rail and spacer) as shown in the illustration.
3. Rotate the crankshaft so that the crank pin is on the center of the cylinder bore.
4. Not to damage the crank pin, attach a special tool MB992010, to the connecting rod bolt.
5. Use suitable thread protectors on the connecting rod bolts before inserting the piston and connecting rod assembly into the cylinder block.
Care must be taken not to nick the crank pin.
6. Insert the piston and connecting rod assembly into the cylinder with the front mark on the piston crown pointing to the timing belt side.
7. Using a suitable piston ring compressor tool, install the piston and connecting rod assembly into the cylinder block.
[F] CONNECTING ROD CAP INSTALLATION
1. Verifying the mark made during disassembly, install the bearing cap to the connecting rod. If the connecting rod is new with no index mark, make sure that the bearing locking notches are on the same side as shown.
2. Make sure that the connecting rod big end side clearance meets the specification.
Standard value: 0.10 - 0.25 mm (0.004 - 0.009 inch)
Limit: 0.4 mm (0.015 inch)
[G] CONNECTING ROD CAP NUT TIGHTENING
1. The connecting rod bolts should be examined before reuse. If the bolt threads are damaged, the bolt should be replaced. Hand-thread the nut to the full length of the bolt threads. If the nut does not run down smoothly, the bolt should be replaced.
2. Before installing each nut, apply engine oil to the threaded portion and bearing surface of the nut.
3. Loosely tighten each nut to the bolt.
4. Then tighten the nuts alternately to the specified torque to install the cap properly.
Tightening torque: 20 ± 2 Nm (14 ± 1 ft-lb)
5. Make a paint mark on the head of each nut.
6. Make a paint mark on the bolt end at the position 90 to 94° from the paint mark made on the nut in the direction of tightening the nut.
CAUTION
^ When the tightening angle is smaller than the specified tightening angle, the appropriate tightening capacity cannot be secured.
^ When the tightening angle is larger than the specified tightening angle, remove the bolt to start from the beginning again according to the procedure.
7. Turn the nut 90 to 94° and make sure that the paint marks on the nut and bolt are aligned.
INSPECTION
PISTON RING
1. Check the piston ring for damage, excessive wear, and breakage. Replace if defects are evident. If the piston has been replaced, the piston rings must also be replaced.
2. Check for clearance between the piston ring and ring groove. If it exceeds the limit, replace the ring or piston, or both.
Standard value:
Number 1: 0.03 - 0.07 mm (0.0012 - 0.0028 inch)
Number 2: 0.02 - 0.06 mm (0.0008 - 0.0024 inch)
Limit: 0.1 mm (0.003 inch)
3. Insert the piston ring into the cylinder bore. Force the ring down with a piston, the piston crown being in contact with the ring, to correctly position it at right angles to the cylinder wall. Then, measure the end gap with a feeler gauge. If the ring gap is excessive, replace the piston ring.
Standard value:
Number 1: 0.15 - 0.30 mm (0.006 - 0.012 inch)
Number 2: 0.28 - 0.43 mm (0.011 - 0.017 inch)
Oil: 0.10 - 0.40 mm (0.003 - 0.015 inch)
Limit:
Number 1, Number 2: 0.8 mm (0.03 inch)
Oil: 1.0 mm (0.03 inch)
CRANKSHAFT PIN OIL CLEARANCE [PLASTIGAGE METHOD]
1. Remove oil from the crankshaft pin and the connecting rod bearing.
2. Cut plastigage to the same length as the width of the bearing and place it on the pin, parallel with its axis.
3. Install the connecting rod cap carefully and tighten the nuts to the specified torque.
4. Carefully remove the connecting rod cap.
5. Measure the width of the plastigage at its widest part by using a scale printed on the plastigage package.
Standard value: 0.03 - 0.06 mm (0.0012 - 0.0023 inch)
Limit: 0.1 mm (0.003 inch)