[11D] ENGINE OVERHAUL <4G6-DOHC> - - PISTON AND CONNECTING ROD - REMOVAL AND INSTALLATION | PRINT PAGE / INDEX / PRIOR / NEXT

PISTON AND CONNECTING ROD

REMOVAL AND INSTALLATION
|  |  | Removal steps
--- | --- | --- | ---
| >>G<< | 1. | Connecting rod cap nut
<<A>> | >>F<< | 2. | Connecting rod cap
| >>E<< | 3. | Connecting rod bearing
| >>D<< | 4. | Piston and connecting rod assembly
|  | 5. | Connecting rod bearing
| >>C<< | 6. | Piston ring No. 1
| >>C<< | 7. | Piston ring No. 2
| >>B<< | 8. | Oil ring
<<B>> | >>A<< | 9. | Piston pin
|  | 10. | Piston
|  | 11. | Connecting rod
|  | 12. | Bolt
| REMOVAL SERVICE POINTS
| <<A>> CONNECTING ROD CAP REMOVAL
| Mark the cylinder number on the side of the connecting rod big end as a guide for reassembly.
| <<B>> PISTON PIN REMOVAL
| The special tool Piston pin setting tool (MD998780), consists of the elements shown in the drawing.
| Insert the tool element, Push rod, into the piston from the front mark side, then attach the element, Guide C, to the push rod. Place the piston and connecting rod assembly on the element, Base, with the front mark facing up. Use a press to remove the piston pin. NOTE: Keep the disassembled pistons, piston pins and connecting rods cylinder by cylinder.
| INSTALLATION SERVICE POINTS
| >>A<< PISTON PIN INSTALLATION
| When replacing a piston, check the cylinder bore size mark stamped at the indicated location on the cylinder block and select an appropriate replacement piston using the following table.
Cylinder bore size mark | Piston size mark
--- | ---
I | A
II | No mark
III | C
NOTE: The piston size mark is located on the piston top surface.
| Measure the following dimensions: A: Piston pin insertion hole length B: Distance between piston bosses C: Piston pin length D: Connecting rod small end width Obtain dimension L from the measurements using the following formula. L =[(A-C) - (B-D)]÷ 2 Insert the tool element, Push rod, into the piston pin and attach the element, Guide A, to the push rod end. Assemble the connecting rod with the piston with their front marks facing in the same direction. Apply engine oil to the outside surface of the piston pin. Insert the assembly of piston pin, Push rod, and Guide A (put together in step 4.) into the piston holes from the front mark side.
| Screw the tool element, Guide B, into the tool element, Guide A until the gap between both the elements is equal to the dimension L (obtained in step 3.) plus 3 mm.
| Place the piston and connecting rod assembly onto the element, Piston setting base, with the front marks facing up. Install the piston pin using a press. If the required press force is less than the standard value, replace the piston and piston pin assembly or the connecting rod, or both. Standard value: 7,350 - 17,100 N
| >>B<< OIL RING INSTALLATION
| Fit the oil ring spacer into the piston ring groove. Install the upper side rail, then the lower side rail. NOTE: Locate the side rail and spacer end gaps as shown in the drawing. NOTE: New spacers and side rails are an identified by color marks as follows:
Size | Color mark
--- | ---
Standard | No mark
0.50 mm oversize | Red
1.00 mm oversize | Yellow
CAUTION Use of ring expander to expand the side rail end gap can break the side rail, unlike other piston rings.
| To install each side rail, first fit one end of the rail into the piston groove, then press the remaining portion progressively into position by finger as shown in the drawing. Make sure that the installed side rails move smoothly in either direction.
| >>C<< PISTON RING NO. 2/PISTON RING NO. 1 INSTALLATION
| Using a piston ring expander, install the piston rings with their identification marks facing up (toward the piston crown). Identification marks: No.1 ring: 1R No.2 ring: 2R NOTE: Each of the available piston rings has a size mark as follows:
Size | Size mark
--- | ---
Standard | No. 1 ring | No mark (white paint on periphery)
No. 2 ring | No mark
0.50 mm oversize | 50
1.00 mm oversize | 100
| >>D<< PISTON AND CONNECTING ROD ASSEMBLY INSTALLATION Apply engine oil generously to the piston's outside surface, piston rings, and oil ring.
| Align the end gaps of the piston rings and oil ring (side rails and spacer) as shown in the drawing. Insert the piston and connecting rod assembly from the top of cylinder with the front mark on the crown toward the camshaft sprocket.
| CAUTION Do not strike the assembly with a large force. Doing so could break the piston rings. When striking the assembly into cylinder, do not allow it to interfere with the oil jet. Use a piston ring band to hold the piston rings compressed when inserting the piston and connecting rod assembly into the cylinder.
| >>E<< CONNECTING ROD BEARING INSTALLATION When replacing the connecting rod bearing, select a bearing of the size appropriate for the crankshaft pin diameter in accordance with the crankshaft pin and connecting rod bearing matching table shown below.
| Crankshaft pin diameter marks are stamped in the indicated locations.
| Connecting rod bearing identification mark is stamped in the indicated location on each bearing.
Crankshaft pin | Connecting rod bearing
--- | ---
Identification mark | Diameter mm | Identification mark
I | 44.995 - 45.000 | 0
II | 44.985 - 44.995 | 1
III | 44.980 - 44.985 | 2
<Bearing selection example> If the crankshaft pin diameter mark is “I,” select a bearing marked “1.” If the crankshaft pin diameter mark is illegible, measure the pin diameter and select a bearing with the mark corresponding to the measurement. Install the upper and lower halves of the selected bearing on the connecting rod big end and cap, respectively.
| >>F<< CONNECTING ROD CAP INSTALLATION
| Install the bearing cap on the connecting rod while aligning the marks made during disassembly. If the connecting rod is new and has no alignment mark, assemble it with the cap such that the both bearing locating notches are on the same side as shown in the drawing.
| Make sure that the thrust clearance of the connecting rod big end is proper. Standard value: 0.10 - 0.25 mm Limit: 0.4 mm
| >>G<< CONNECTING ROD CAP NUT INSTALLATION The connecting rod cap bolts and nuts are tightened using the torque-to-yield method. For this reason, each bolt to be reused must be checked for elongation before installation. Whether or not the bolt has been elongated can be determined by running a nut with fingers through all the threads of the bolt. If the nut does not turn smoothly over all the threads, the bolt has been elongated and must be replaced. Apply engine oil to the threads and bearing surface of each nut before installation. Finger-tighten the nuts on the bolts, then tighten the nuts alternately and repeatedly to install the cap properly. Tighten the nuts to a torque of 20 ± 2 N·m.
| Make a paint mark on the head of each nut. CAUTION If the tightening angle is less than 90°, adequate tightness could not be assured. If the tightening angle exceeds 94°, loosen the nut completely and then perform the tightening procedure again beginning with the first step. Make a paint mark on the bolt at a point 90° to 94° away from the paint mark made on the nut in the tightening direction. Turn the nut 90° to 94° to bring the mark on the nut into alignment with that on the bolt.

[11D] ENGINE OVERHAUL <4G6-DOHC> - - PISTON AND CONNECTING ROD - REMOVAL AND INSTALLATION | PRINT PAGE / INDEX / PRIOR / NEXT

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