Inspection

INSPECTION PISTON AND PISTON PIN CLEARANCE
1. Measure inner diameter of piston pin hole "Dp".
Standard diameter "Dp":
20.969 - 20.981 mm (0.8255 - 0.8260 in)






2. Measure outer diameter of piston pin "Dp".
Standard diameter "Dp":
20.971 - 20.983 mm (0.8256 - 0.8261 in)
3. Calculate piston pin clearance.
dp - Dp = O to - 0.004 mm (O to - 0.0002 in)
If it exceeds the above value, replace piston assembly with pin.






PISTON RING SIDE CLEARANCE
Side clearance:
Top ring
0.040 - 0.073 mm (0.0016 - 0.0029 in)
2nd ring
0.030 - 0.063 mm (0.0012 - 0.0025 in)
Max. limit of side clearance:
0.1 mm (0.004 in)
If out of specification, replace piston and/or piston ring assembly.






PISTON RING END GAP End gap:
Top ring
0.21 - 0.44 mm (0.0083 - 0.0173 in)
2nd ring
0.18 - 0.44 mm (0.0071 - 0.0173 in)
Oil ring
0.20 - 0.76 mm (0.0079 - 0.0299 in)
Max. limit of ring gap:
1.0 mm (0.039 in)
If out of specification, replace piston ring. If gap still exceeds the limit even with a new ring, rebore cylinder and use oversized piston and piston rings.






CONNECTING ROD BEND AND TORSION
Bend:
Limit 0.10 mm (0.0039 in) per 100 mm (3.94 in) length
Torsion:
Limit 0.10 mm (0.0039 in) per 100 mm (3.94 in) length
If it exceeds the limit, replace connecting rod assembly.






CYLINDER BLOCK DISTORTION AND WEAR
1. Clean upper face of cylinder block and measure the distortion.
Limit:
0.10 mm (0.0039 in)
2. If out of specification, resurface it. The resurfacing limit is determined by cylinder head resurfacing in engine.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 in)
Nominal cylinder block height from crankshaft center:
227.60 - 227.70 mm (8.9606 - 8.9645 in)
3. 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:
87.000 - 87.030 mm (3.4252 - 3.4264 in)
Wear limit:
0.20 mm (0.0079 in)
Out-f-round (X - y) limit:
0.015 mm (0.0006 in)
Taper (A - B) limit:
0.015 mm (0.0006 in)
If it exceeds the limit, rebore all cylinders. Replace cylinder block if necessary.
2. Check for scratches and seizure. If seizure is found, hone it.






- If both cylinder block and piston are replaced with new ones, select piston of the same grade number punched on cylinder block upper surface.






3. Measure piston skirt diameter.
Piston diameter "A":
Measuring point "a" (Distance from the bottom):
18 mm (0.71 in)
4. Check that piston-to-bore clearance is within specification.
Piston-to-bore clearance "B":
0.015 - 0.035 mm (0.0006 - 0.0014 in)
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 in)
7. Install main bearing caps, and tighten to the specified torque to prevent distortion of cylinder bores in final assembly.
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 in) or so in diameter at a time.
9. Hone cylinders to obtain specified piston-to-bore clearance.
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 - Less than 0.005 mm (0.0002 in)
Taper (A - B):
Less than 0.005 mm (0.0002 in)






3. Measure crankshaft runout.
Runout total indicator reading):
Less than 0.10 mm (0.0039 in)






BEARING CLEARANCE
- Either of the following two methods may be used, however, method A gives more reliable results and is preferable.
Method A (Using bore gauge & 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 crankshaft main journal.
5. Calculate main bearing clearance.
Main bearing clearance (A - Dm):
Standard 0.028 - 0.055 mm (0.0011 - 0.0022 in)
Limit 0.090 mm (0.0035 in)
6. If it exceeds the limit, replace bearing.
7. If clearance cannot be adjusted within the standard of any bearing, grind crankshaft journal and use undersized bearing.






a. When grinding crankshaft journal, confirm that "L" dimension in fillet roll is more than the specified limit.
"L": 0.1 mm (0.004 in)
b. for grinding crankshaft and available service-parts.






8. If crankshaft is reused, measure main bearing clearances and select thickness of main bearings.
If crankshaft is replaced with a new one, it is necessary to 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.
c. Select main bearing with suitable thickness according to the following table.






For example:
Main journal grade number: 1
Crankshaft journal grade number: 2
Main bearing grade number = 1 + 2 = 3






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 - 0.054 mm (0.0006 - 0.0021 in)
Limit
0.090 mm (0.0035 in)
6. If it exceeds the limit, replace bearing.
7. If clearance cannot be adjusted within the standard of any bearing, grind crankshaft journal and use undersized bearing.






Method B (Using plastigage)
CAUTION:
- Do not turn crankshaft or connecting rod while plastigage is being inserted.
- When bearing clearance exceeds the specified limit, ensure that the proper bearing has been installed. Then if excessive bearing clearance exists, use a thicker main bearing or undersized bearing so that the specified beaing clearance is obtained.






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 in)
Limit:
0.023 mm (0.0009 in)
If it exceeds the limit, replace connecting rod assembly or connecting rod bushing and/or piston set with 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. After driving in small end bushing, ream the bushing so that clearance between connecting rod bushing and piston pin is the specified value.
Clearance between connecting rod bushing and piston pin:
0.005 - 0.017 mm (0.0002 - 0.0007 in)
DRIVE PLATE RUNOUT
Runout (Total indicator reading):
Less than 0.15 mm (0.0059 in)