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Piston and Connecting Rod

PISTON AND CONNECTING ROD








REMOVAL AND INSTALLATION

Required Special Tool: MIT216941: Piston Pin Setting Tool

Removal Service Point
<> 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.

<> 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. 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.
2. Using the markings on the press pin, adjust the stop screw to the depth shown on the instruction for special tool MIT21 6941.





3. Place the base on press support blocks.
4. Slide the piston pin over the threaded end of the press pin, and thread the correct guide pin up against it.
5. Coat the piston pin with engine oil. With the connecting rod held in position, slide the guide pin through the piston and connecting rod.
6. 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.

7. Remove the piston assembly from the base. Remove the guide pin and press pin from the assembly.





8. Check that the piston moves smoothly.

>>B<< Oil Ring Installation








1. Fit the oil ring spacer into the piston ring groove.

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.

CAUTION: Do not use a piston ring expander when installing 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 finger. See illustration.
3. Install the lower side rail in the same procedure 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 Installation








1. To prevent wrong installation, check the identification mark of each piston ring. The identification mark is stamped near the ring gap:
Identification mark:
Number 1 ring 1 R
Number 2 ring 2R

NOTE: Size marks on piston rings are as follows.





2. 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.

3. Install the number 1 piston ring in the same manner as step 2.

>>D<< Connecting Rod Bearing Installation








1. Measure the crankshaft pin diameter and confirm its classification from the following table. In the case of a crankshaft supplied as a service part, identification colors/ marks of its pins are painted /stamped at the positions shown in the illustration.





2. If the crankshaft pin outside diameter ID color is yellow, for example, select a bearing whose ID mark is 1 or ID color is yellow. If there is no ID 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 on 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 crank pin is on the center of the cylinder bore.





4. 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.
5. Insert the piston and connecting rod assembly into the cylinder with front mark on the piston crown pointing to the timing belt side.
6. 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 installation of 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 a torque of 20 ± 2 Nm (14 ± 1 ft. lbs.) to install the cap properly.





5. Make a paint mark on the head of each nut.
6. Make a paint mark on the bolt end at the position 90° angle to 94° angle from the paint mark made on the nut in the direction of tightening the nut.

CAUTION:
- If the nut is turned less than 90 degree angle, proper fastening performance may not be achieved. Be careful to tighten the nut exactly 90 degree angle.
- If the nut is overtightened (exceeding 94 degree angle), loosen the nut completely and then retighten it by repeating the tightening procedure from step 3.

7. Turn the nut further 90 degree angle to 94 degree angle and make sure that the paint marks on the nut and bolt are aligned.
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