CLEAN PISTON
Using an old piston ring or similar device, remove all carbon on each piston.
CAUTION:
Wear protective goggles while servicing.
Note
Do not damage the piston while servicing.
Clean all the carbon off each part using solvent.
INSPECT CYLINDER BLOCK
Using a straightedge and feeler gauge, measure the warpage of the contact surface indicated in the illustration.
| Maximum warpage |
|---|
| 0.05 mm (0.002 in.) |
If the warpage is greater than the maximum, replace the cylinder block.
INSPECT CYLINDER BORE
Using a cylinder gauge, measure the cylinder bore diameter in the thrust and axial directions at the position shown in the illustration.
| Standard diameter |
|---|
| 71.000 to 71.013 mm (2.79527 to 2.79578 in.) |
| Maximum diameter |
|---|
| 71.133 mm (2.80051 in.) |
If the cylinder bore diameter is greater than the maximum, replace the cylinder block.
INSPECT PISTON
Measure the outer diameter of the piston in the vertical direction to the pin hole, at the point 12.7 mm (0.500 in.) away from the bottom end of the skit.
| Piston diameter |
|---|
| 70.945 to 70.963 mm (2.79311 to 2.79381 in.) |
| Minimum diameter |
|---|
| 70.945 mm (2.79311 in.) |
If the diameter is not as specified, replace the piston.
INSPECT PISTON RING GROOVE CLEARANCE
Using a feeler gauge, measure the clearance between a new piston ring and the wall of the ring groove.
| Standard Ring Groove Clearance | ||||||||
|---|---|---|---|---|---|---|---|---|
|
If the ring groove clearance is not as specified, replace the piston assembly.
INSPECT PISTON RING END GAP
Using a piston, push the piston ring a little beyond the bottom of the ring travel, which is 55 mm (2.165 in.) from the top of the cylinder block.
Using a feeler gauge, measure the end gap.
| Standard End Gap | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| Maximum End Gap | ||||||||
|---|---|---|---|---|---|---|---|---|
|
If the end gap is greater than the maximum, replace the piston ring.
If the end gap is greater than the maximum, even with a new piston ring, replace the cylinder block.
INSPECT PISTON OIL CLEARANCE
Subtract the piston diameter measurement from the cylinder bore diameter measurement to calculate the oil clearance.
| Standard oil clearance |
|---|
| 0.037 to 0.068 mm (0.00146 to 0.00268 in.) |
| Maximum oil clearance |
|---|
| 0.098 mm (0.00386 in.) |
If the clearance is greater than the maximum, replace all of the piston assemblies.
If necessary, replace the cylinder block.
Tech Tips
The oil clearance of the piston and cylinder block can be calculated by subtracting the cylinder inner diameter in the thrust direction from the piston outer diameter.
Perform the measurement at the point with the most wear because there is joggling wear on the upper end of the piston ring sliding area.
INSPECT CONNECTING ROD SUB-ASSEMBLY
Using a cylinder gauge, measure the connecting rod sub-assembly big end diameter, as shown in the illustration.
| Standard diameter | ||||||||
|---|---|---|---|---|---|---|---|---|
|
If the diameter is not as specified, replace the connecting rod.
INSPECT CONNECTING ROD BOLT
Using a vernier caliper, measure the tension portion.
| Minimum diameter |
|---|
| 6.4 mm (0.252 in.) |
If the diameter is less than the minimum, replace the connecting rod bolt.
INSPECT CONNECTING ROD BEARING
Using a micrometer, measure the thickness of the connecting rod bearing.
| Standard thickness |
|---|
| 1.492 to 1.501 mm (0.05874 to 0.05909 in.) |
If the thickness is not as specified, replace the connecting rod bearing.
INSPECT CONNECTING ROD THRUST CLEARANCE
Install the crankshaft with crankshaft journal bearing onto the cylinder block.
Install the thrust washer upper.
Install the piston with pin into the connecting rod.
Install the piston ring onto the piston.
Install the connecting rod assembly with connecting rod bearing onto the crankshaft.
Using a feeler gauge, measure the thrust clearance of the connecting rod.
| Standard thrust clearance |
|---|
| 0.1 to 0.3 mm (0.004 to 0.012 in.) |
| Maximum thrust clearance |
|---|
| 0.36 mm (0.0138 in.) |
INSPECT CONNECTING ROD OIL CLEARANCE
Remove the 2 bolts, connecting rod bearing cap and connecting rod bearing.
Note
Arrange the removed parts for each cylinder.
Clean the connecting rod bearing and crank pin.
| *1 | Plastigage |
Lay a strip of Plastigage across the crank pin.
Apply a light coat of engine oil to the threads and under the heads of the 2 bolts.
Tighten the 2 bolts in several passes to the specified torque.
Note
Do not turn the crankshaft.
| *a | Paint Mark |
| *b | Engine Front |
Mark the front of the 2 bolts with paint.
Retighten the 2 bolts by an additional 90° as shown in the illustration.
Remove the 2 bolts, then remove the connecting rod bearing cap and connecting rod bearing.
| *1 | Plastigage |
| *a | Mark |
Measure the Plastigage at its widest point.
| Standard oil clearance |
|---|
| 0.010 to 0.036 mm (0.00039 to 0.00142 in.) |
| Maximum oil clearance |
|---|
| 0.036 mm (0.00142 in.) |
If the oil clearance is greater than the maximum, replace the connecting rod bearings. If necessary, inspect the crankshaft.
If replacing a bearing, replace it with one that has the same number as its respective connecting rod cap. Each bearing's standard thickness is indicated by mark 1, 2, or 3 on its surface.
| Standard Connecting Rod Bearing Cap Bore Diameter | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| Standard Connecting Rod Bearing Thickness | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| Standard Crankshaft Pin Diameter | ||||
|---|---|---|---|---|
|
Note
Completely remove the Plastigage after the measurement.
Tech Tips
The procedures for measuring the connecting rod bearing cap bore diameter and the connecting rod thickness are described in the engine unit inspection section.
Perform the measurement for the other connecting rod oil clearance using the same procedure.
INSPECT CRANKSHAFT
Using a dial indicator and V-blocks, measure the circle runout as shown in the illustration.
| Standard circle runout |
|---|
| 0.03 mm (0.0012 in.) |
| Maximum circle runout |
|---|
| 0.04 mm (0.0016 in.) |
If the circle runout is greater than the maximum, replace the crankshaft.
Tech Tips
The runout is the half of the value on the indicator when the crankshaft is turned 1 revolution.
Using a micrometer, measure the diameter of each main journal at the points shown in the illustration.
| Diameter |
|---|
| 43.988 to 44.000 mm (1.73181 to 1.73228 in.) |
If the diameter is not as specified, check the crankshaft oil clearance.
Check each main journal for elliptic degree and tapered amount as shown.
| Maximum elliptic degree and tapered amount |
|---|
| 0.03 mm (0.0012 in.) |
If the elliptic degree or tapered amount is greater than the maximum, replace the crankshaft.
Tech Tips
Elliptic degree: A - B or a - b
Tapered amount: A - a or B - b
Using a micrometer, measure the diameter of each crankshaft pin at the points shown in the illustration.
| Diameter |
|---|
| 39.992 to 40.000 mm (1.57449 to 1.57480 in.) |
If the diameter is not as specified, check the connecting rod oil clearance.
Check each crankshaft pin for elliptic degree and tapered amount as shown.
| Maximum elliptic degree and tapered amount |
|---|
| 0.03 mm (0.0012 in.) |
If the elliptic degree or tapered amount is greater than the maximum, replace the crankshaft.
Tech Tips
Elliptic degree: A - B or a - b
Tapered amount: A - a or B - b
INSPECT CRANKSHAFT THRUST CLEARANCE
Install the crankshaft with crankshaft bearing onto the cylinder block.
Using a feeler gauge, measure the thrust clearance while prying the crankshaft back and forth with a screwdriver.
| Standard clearance |
|---|
| 0.02 to 0.04 mm (0.0008 to 0.0016 in.) |
| Maximum clearance |
|---|
| 0.30 mm (0.0118 in.) |
Tech Tips
If the thrust clearance is greater than the maximum, replace the thrust washer.
If the clearance is still greater than the maximum, replace the crankshaft.
INSPECT CRANKSHAFT OIL CLEARANCE
Loosen the 8 bolts in 2 or 3 steps and in the order shown in the illustration.
Remove the 8 bolts and the 4 crankshaft bearing caps.
Note
Arrange the removed parts in the removed order.
Tech Tips
If it is difficult to remove the crankshaft bearing cap, lightly tap it with a hammer.
Move the top of the crankshaft bearing cap back and forth in the axial direction.
Clean the inner surfaces of the crankshaft bearing and crankshaft bearing cap and the journals of the cylinder block and crankshaft.
Check these parts for excessive wear and damage.
| *1 | Plastigage |
Lay a strip of Plastigage in the axial direction of the crankshaft journal.
Tighten the 8 bolts in 2 or 3 steps and in the order shown in the illustration.
Note
Do not turn the crankshaft.
Remove the 2 bolts, then remove the crankshaft bearing cap and crankshaft bearing.
| *1 | Plastigage |
| *a | Mark |
| *b | No. 1 |
| *c | No. 2 |
| *d | No. 3 |
| *e | No. 4 |
Measure the Plastigage at its widest point.
| Standard oil clearance |
|---|
| 0.006 to 0.024 mm (0.00024 to 0.00094 in.) |
| Maximum oil clearance |
|---|
| 0.024 mm (0.00094 in.) |
If the oil clearance is greater than the maximum, replace the crankshaft bearing. If necessary, replace the crankshaft.
If replacing a bearing, select a new one with the same number. If the number of the bearing cannot be determined, calculate the correct bearing number by adding together the numbers imprinted on the cylinder block and crankshaft. Then select a new bearing with the calculated number according to the chart below. There are 4 sizes of standard bearings, marked "2", "3", "4" and "5" accordingly.
EXAMPLE: Cylinder block mark "2" + Crankshaft mark "2" = Use bearing mark "4"
| Standard Cylinder Block Journal Bore Diameter | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| Standard Crankshaft Journal Diameter | ||||||
|---|---|---|---|---|---|---|
|
| Standard Bearing Center Wall Thickness | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
Note
Completely remove the Plastigage after the measurement.