Disassembly and Inspection

CAUTION:
- When installing sliding parts such as bearings and pistons, apply engine oil on the sliding surfaces.
- Place removed parts, such as bearings and bearing caps, in their proper order and direction.
- When installing connecting rod nuts and main bearing cap bolts, apply new engine oil to threads and seating surfaces.
- Do not allow any magnetic materials to contact the ring gear teeth of flywheel or drive plate, and rear plate.

DISASSEMBLY

Piston And Crankshaft





1. Place engine on a work stand.
2. Drain coolant and oil.
3. Remove timing chain.





4. Remove pistons with connecting rod.
- When disassembling piston and connecting rod, remove snap ring first. Then heat piston to 60 to 70° C (140 to 158° F) or use piston pin press stand at room temperature.

CAUTION:
- When piston rings are not replaced, make sure that piston rings are mounted in their original positions.
- When replacing piston rings, if there is no punch mark, install with either side up.





5. Loosen main bearing caps in numerical order as shown in figure.
6. Remove bearing caps, main bearings and crankshaft.
- Before removing bearing caps, measure crankshaft end play.
- Bolts should be loosened in two or three steps.

INSPECTION





Piston And Piston Pin Clearance
1. Measure inner diameter of piston pin hole "dp".

Standard diameter "dp": 18.987 -18.999 mm (0.7475 - 0.7480 inch)





2. Measure outer diameter of piston pin "Dp

Standard diameter "Dp": 18.989 - 19.001 mm (0.7476 - 0.7481 inch)

3. Calculate piston pin clearance.

Dp - dp = -0.004 to 0 mm (-0.0002 to 0 inch)

If it exceeds the above value, replace piston assembly with pin.

Piston Ring Side Clearance





Side clearance:
Top ring: 0.040 - 0.080 mm (0.0016 - 0.0031 inch)
Max. limit of side clearance: 0.1 mm (0.004 inch)

If out of specification, replace piston and/or piston ring assembly.

Piston Ring End Gap





End gap:
Top ring: 0.20 - 0.44 mm (0.0079 - 0.0173 inch)
Oil ring: 0.20 - 0.69 mm (0.0079 - 0.0272 inch)
Max. limit of ring gap:
Top ring: 0.49 mm (0.0193 inch)
Oil ring: 0.69 mm (0.0272 inch)

If out of specification, replace piston ring. If gap exceeds maximum limit with a new ring, rebore cylinder and use oversized piston and piston rings.
- When replacing the piston, check the cylinder block surface for scratches or seizure. If scratches or seizure is found, hone or replace the cylinder block.

Connecting Rod Bend And Torsion








Bend Limit: 0.15 mm (0.0059 inch) per 100 mm (3.94 inch) length
Torsion Limit: 0.3 mm (0.012 inch) per 100 mm (3.94 inch) length

If it exceeds the limit, replace connecting rod assembly.

Cylinder Block Distortion And Wear








Clean upper surface of cylinder block. Use a reliable straightedge and feeler gauge to check the flatness of cylinder block surface. Check along six positions shown in figure.

Block surface flatness:
Standard: Less than 0.03 mm (0.0012 inch)
Limit: 0.10 mm (0.004 inch)

If out of specification, resurface it. The limit for cylinder block resurfacing is determined by the amount of cylinder head resurfacing.

Amount of cylinder head resurfacing is "A".

Amount of cylinder block resurfacing is "B".
The maximum limit is as follows: A + B = 0.2 mm (0.008 inch)
Nominal cylinder block height from crankshaft center: 213.95 - 214.05 mm (8.4232 - 8.4271 inch)

If necessary, replace cylinder block.

Piston-To-Bore Clearance





1. Using a bore gauge, measure cylinder bore for wear, out-of-round and taper.

Standard inner diameter: 76.000 - 76.010 mm (2.9921 - 2.9925 inch)
Wear limit: 0.2 mm (0.008 inch)
Out-of-round (X - Y) standard: Less than 0.015 mm (0.0006 inch)
Taper (A - B) standard: Less than 0.01 mm (0.0004 inch)

If it exceeds the limit, rebore all cylinders. Replace cylinder block if necessary.





2. Check for score and seizure. If seizure is found, hone it.
- If cylinder block or piston is replaced, match piston grade with grade number on cylinder block lower surface.





3. Measure piston skirt diameter.

Piston diameter "A":
Measuring point "a" (Distance from the bottom): 9.9 mm (0.390 inch)

4. Check that piston-to-bore clearance is within specification.

Piston-to-bore clearance = cylinder bore measurement "B" - Piston diameter "A": 0.015 - 0.035 mm (0.0006 - 0.0014 inch)

5. Determine piston oversize according to amount of cylinder wear.
Oversize pistons are available for service.
6. Cylinder bore size is determined by adding piston-to-bore clearance to piston diameter "A".

Rebored size calculation: D=A+B-C where,
D: Bored diameter
A: Piston diameter as measured
B: Piston-to-bore clearance
C: Honing allowance 0.02 mm (0.0008 inch)

7. Install main bearing caps and tighten bolts to the specified torque. This will prevent distortion of cylinder bores.
8. Cut cylinder bores.
- When any cylinder needs boring, all other cylinders must also be bored.
- Do not cut too much out of cylinder bore at a time. Cut only 0.05 mm (0.0020 inch) or so at a time.
9. Hone cylinders to obtain specified piston-to-bore clearance.
10. Measure finished cylinder bore for out-of-round and taper.
- Measurement should be done after cylinder bore cools down.

Crankshaft





1. Check crankshaft main and pin journals for score, wear or cracks.
2. With a micrometer, measure journals for taper and out-of-round.

Out-of-round (X - Y): Less than 0.002 mm (0.0001 inch)
Taper (A - B): Less than 0.003 mm (0.0001 inch)





3. Measure crankshaft runout.

Runout (Total indicator reading): Less than 0.04 mm (0.0016 inch)

Bearing Clearance





- Use Method A or Method B. Method A is preferred because it is more accurate.

Method A (Using bore gauge and micrometer)
Main bearing
1. Set main bearings in their proper positions on cylinder block and main bearing cap.





2. Install main bearing cap to cylinder block.

Tighten all bolts in correct order in two or three stages.

3. Measure inner diameter "A" of each main bearing.








4. Measure outer diameter "Dm" of each main journal in crankshaft.
5. Calculate main bearing clearance.
Main bearing clearance = A - Dm

Standard: 0.018 - 0.042 mm (0.0007 - 0.0017 inch)
Limit: 0.1 mm (0.004 inch)

If it exceeds the limit, replace bearing.
If clearance cannot be adjusted within standard of any bearing, grind crankshaft journal and use undersized bearing.
When grinding crank pin and crank journal:
- Grind until clearance is within specified standard bearing clearance.
- Fillets should be finished as shown in the image. R: 2.3 - 2.5 mm (0.091 - 0.098 inch)














6. If the crankshaft is replaced, select thickness of main bearings as follows:
a. Grade number of each cylinder block main journal is punched on the respective cylinder block. These numbers are punched in either Arabic or Roman numerals.
b. Grade number of each crankshaft main journal is punched on the respective crankshaft. These numbers are punched in either Arabic or Roman numerals. Select main bearing with suitable thickness according to the following table.

Connecting rod bearing (Big end)





1. Install connecting rod bearing to connecting rod and cap.
2. Install connecting rod cap to connecting rod.
- Tighten bolts to the specified torque.
3. Measure inner diameter "C" of each bearing.











4. Measure outer diameter "Dp" of each crankshaft pin journal.
5. Calculate connecting rod bearing clearance.

Connecting rod bearing clearance = C - Dp
Standard: 0.014 - 0.039 mm (0.0006 - 0.0015 inch)
Limit: 0.1 mm (0.004 inch)

If it exceeds the limit, replace bearing. If clearance cannot be adjusted using any standard bearing grade, grind crankshaft journal and use undersized bearing.
- If a new bearing, crankshaft or connecting rod is replaced, select connecting rod bearing according to the following table.

Connecting rod bearing grade number:
These numbers are punched in either Arabic or Roman numerals.

Method B (Using Plastigage)





CAUTION:
- Do not turn crankshaft or connecting rod while Plastigage is being inserted.
- If incorrect bearing clearance exists, use a thicker or undersized main bearing to ensure specified clearance.

Connecting Rod Bushing Clearance (Small end)





1. Measure inner diameter "C" of bushing.





2. Measure outer diameter "Dp" of piston pin.
3. Calculate connecting rod bushing clearance.

Connecting rod bushing clearance = C - Dp
Standard: 0.005 - 0.017 mm (0.0002 - 0.0007 inch)
Limit: 0.023 mm (0.0009 inch)

If it exceeds the limit, replace connecting rod assembly or connecting rod bushing and/or piston pin.

Replacement Of Connecting Rod Bushing (Small End)





1. Drive in small end bushing until it is flush with end surface of rod.
Be sure to align the oil holes.
2. Ream the bushing so that clearance with piston pin is within specification.
Clearance between connecting rod bushing and piston pin: 0.005 - 0.017 mm (0.0002 - 0.0007 inch)

Flywheel/Driveplate Runout





Runout (Total indicator reading):
Flywheel (M/T models): Less than 0.15 mm (0.0059 inch)
Drive plate (A/T models)*: Less than 0.2 mm (0.008 inch)
*Measuring points: Approximately 115 mm (4.53 inch) from crankshaft center

CAUTION:
- Do not allow any magnetic materials to contact the ring gear teeth and rear plate.
- Do not resurface flywheel. Replace as necessary.