Cylinder Block Assembly: Service and Repair
Legend
(1) Flywheel
(2) Rear plate
(3) Rear oil seal
(4) Rear oil seal retainer
(5) Piston ring
(6) Snap ring
(7) Piston pin
(8) Piston
(9) Connecting rod
(10) Connecting bearing
(11) Thrust bearing
(12) Main bearing
(13) Key
(14) Connecting rod cap
(15) Bearing beam cap
(16) Oil pan
(17) Drive plate
(18) Dust cover
CAUTION:
^ When installing sliding parts such as bearings and pistons, be sure to apply engine oil on the sliding surfaces.
^ Place removed parts such as bearings and bearing caps in their proper order and direction.
^ When tightening connecting rod bolts and main bearing cap bolts, apply engine oil to thread portion of bolts and seating surface of nuts.
DISASSEMBLY
PISTON AND CRANKSHAFT
1. Place engine on a work stand.
2. Drain coolant and oil.
3. Remove timing chain. Refer to "Removal" in "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.
5. Remove bearing caps 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":
18.981 - 18.999 mm (0.7475 - 0.7480 in)
2. Measure outer diameter of piston pin "Dp".
Standard diameter "Dp":
18.989 - 19.001 mm (0.7476 - 0.7481 in)
3. Calculate piston pin clearance.
dp - Dp A).004 to 0 mm (A).0002 to 0 in)
Note: 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 in)
2nd ring
0.030 - 0.070 mm (0.0012 - 0.0028 in)
Max. limit of side clearance:
0.2 mm (0.008 in)
Note: If out of specification, replace piston and/or piston ring assembly.
PISTON RING END GAP
End gap:
Top ring 0.20- 0.35 mm (0.0079 - 0.0138 in)
2nd ring 0.37- 0.52 mm (0.0146 - 0.0205 in)
Oil ring 0.20- 0.60 mm (0.0079 - 0.0236 in)
Max. limit of ring gap:
1.0 mm (0.039 in)
Note: 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:
0.15 mm (0.0059 in) per 100 mm (3.94 In) length
Torsion limit:
0.3 mm (0.012 in) per 100 mm (3.94 in) length
Note: 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:
213.95-214.05 mm (8.4232 - 8.4271 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:
76.000 - 76.030 mm (2.9921 - 2.9933 in)
Wear limit: 0.2 mm (0.008 in)
Out-of-round (X - Y) limit: 0.015 mm (0.0006 in)
Taper (A - B) limit: 0.01 mm (0.0004 in)
Note: 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 lower surface.
3. Measure piston skirt diameter.
Piston diameter "A":
Refer to Specifications.
Measuring point "a" (Distance from the bottom):
9.5 mm (0.374 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.
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 0.005 mm (0.0002 in)
Taper (A - B):
Less than 0.002 mm (0.0001 in)
3. Measure crankshaft runout.
Runout (Total indicator reading):
Less than 0.05 mm (0.0020 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 main journal in crankshaft.
5. Calculate main bearing clearance.
Main bearing clearance = A - Dm
Standard: 0.018 - 0.042 mm (0.0007 - 0.0011 in)
Limit: 0.1 mm (0.004 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.
When grinding crank pin and crank journal:
a. Grind until clearance is within specified standard bearing clearance.
b. Fillets should be finished as shown in the image.
R: 2.3 - 2.5 mm (0.091 - 0.098 in)
Refer to Specifications for standard bearing clearance.
8. If crankshaft, cylinder block or main bearing is reused again, measure main bearing clearance. If crankshaft, cylinder block and main bearings are replaced with new ones, 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.
b. Grade number of each crankshaft main journal is punched on the respective crankshaft.
c. Select main bearing with suitable thickness according to the image.
For example:
Main journal grade number: 1
Crankshaft journal grade number: 2
Main bearing grade number = 1 + 2 = Yellow
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: 0.010 - 0.035 mm (0.0004 - 0.0014 in)
Limit: 0.1 mm (0.004 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. Refer to step 7 of "BEARING CLEARANCE - Main bearing".
8. If bearing, crankshaft or connecting rod is replaced with a new one, select connecting rod bearing according to the image.
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 bearing 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)
Note: 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.
Note: Be sure to align the oil holes.
2. After driving in small end bushing, ream the bushing so that clearance between connecting rod busing and piston pin achieves specified value.
Clearance between connecting rod bushing and piston pin: 0.005 - 0.017 mm (0.0002 - 0.0007 in)
FLYWHEEL RUNOUT
Runout (Total indicator reading):
Flywheel
Less than 0.15 mm (0.0059 in)
ASSEMBLY
PISTON
1. Install new snap ring on one side of piston pin hole.
2. Heat piston to 60 to 70°C (140 to 158°F) and assemble piston, piston pin, connecting rod and new snap ring.
^ Align the direction of piston and connecting rod.
^ Numbers stamped on connecting rod and cap correspond to each cylinder.
^ After assembly, make sure connecting rod swings smoothly.
3. Set piston rings as shown in image.
CAUTION:
^ When piston rings are not replaced, make sure that piston rings are mounted in their original position.
^ When piston rings are being replaced and no punch mark is present, piston rings can be mounted with either side up.
CRANKSHAFT
1. Set main bearings in their proper positions on cylinder block and main bearing cap.
^ Confirm that correct main bearings are used. Refer to "Inspection".
2. Install crankshaft and main bearing caps and tighten bolts to the specified torque.
^ Prior to tightening bearing cap bolts, place bearing cap in its proper position by shifting crankshaft in the axial direction.
^ Tighten bearing cap bolts gradually in two or three stages. Start with center bearing and move outward sequentially.
^ After securing bearing cap bolts, make sure crankshaft turns smoothly by hand.
3. Measure crankshaft end play.
Crankshaft end play:
Standard
0.060 - 0.180 mm (0.0024 - 0.0071 in)
Limit
0.3mm (0.012 in)
If beyond the limit, replace thrust bearing with a new one.
4. Install connecting rod bearings in connecting rods and connecting rod caps.
^ Confirm that correct bearings are used. Refer to "Inspection".
^ Install bearings so that oil hole in connecting rod aligns with oil hole of bearing.
5. Install pistons with connecting rods.
a. Install them into corresponding cylinders with Tool.
^ Be careful not to scratch cylinder wall by connecting rod.
^ Arrange so that front mark on piston head faces toward front of engine.
b. Install connecting rod caps.
Tighten connecting rod cap nuts to the specified torque.
Tighten: Connecting rod cap nuts
(1) Tighten to 14 to 16 N-m (1.4 to 1.6 kg-m, 10 to 12 ft-lb).
(2) Turn nuts to 35 to 40 degrees clockwise with an angle wrench. If an angle wrench is not available tighten nuts to 23 to 28 N-m (2.3 to 2.9 kg-m, 17 to 21 ft-lb).
6. Measure connecting rod side clearance.
Connecting rod side clearance:
Standard
0.200 - 0.470 mm (0.0079 - 0.0185 in)
Limit
0.50 mm (0.0197 in)
If beyond the limit, replace connecting rod and/or crankshaft.
7. Install rear oil seal retainer.
a. Before installing rear oil seal retainer remove old liquid gasket from cylinder block and retainer.
b. Apply a continuous bead of liquid gasket to rear oil seal retainer.
^ Apply around inner side of bolt holes.