Inspection After Disassembly

CYLINDER BLOCK


Inspection After Disassembly


CRANKSHAFT SIDE CLEARANCE





- Using a dial gauge, measure the clearance between the thrust bearings and the crankshaft arm when the crankshaft is moved fully forward or backward.





- If the measured value exceeds the limit, replace the thrust bearings, and measure again. If it still exceeds the limit, replace the crankshaft.

CONNECTING ROD SIDE CLEARANCE





- Measure side clearance between connecting rod and crankshaft arm using a feeler gauge.






- If the measured value exceeds the limit, replace the connecting rod bearings, and measure again. If it still exceeds the limit, replace the crankshaft also.

PISTON AND PISTON PIN CLEARANCE

Diameter of Piston Pin Bore





- Measure the diameter of piston pin bore using an inside micrometer. [1][2]Specifications.

Outer Diameter of Piston Pin





- Measure outer diameter of piston pin using a micrometer. Refer to
[1][2]Specifications.

Piston to Piston Pin Clearance
(Piston pin clearance) = (Piston pin bore diameter) � (Outer diameter of piston pin)





- A: Front mark
- B: Piston pin bore grade
- C: Piston grade I.D. stamp
- D: Piston crown I.D. code stamp






- If clearance exceeds specification, replace either or both of piston/piston pin assembly and connecting rod assembly with reference to specification of each parts.
- Use the piston selection table to replace piston/piston pin assembly. Service and Repair.
- Use the connecting rod bearing selection table to replace connecting rod. Service and Repair.

NOTE:





- The connecting rod small end grade and piston pin hole (piston pin) grade are provided only for the parts installed at the plant. For service parts, no grades can be selected. Only 0 grade is available.
- Follow the "CONNECTING ROD BUSHING OIL CLEARANCE
(SMALL END)" procedure for the values for each grade at the plant.

PISTON RING SIDE CLEARANCE





- Measure side clearance of piston ring and piston ring groove using a feeler gauge. [1][2]Specifications.
- If out of specification, replace piston and/or piston ring assembly.

PISTON RING END GAP





- Check if inner diameter of cylinder bore is within specification. Follow the "PISTON TO CYLINDER BORE CLEARANCE".
- Insert piston ring until middle of cylinder with piston, and measure gap using a feeler gauge. [1][2]Specifications.
- If out of specification, replace piston ring.

CONNECTING ROD BEND AND TORSION





- Check with connecting rod aligner. [1][2]Specifications, "Standard
and Limit".





- If it exceeds the limit, replace connecting rod assembly.

CONNECTING ROD BEARING (BIG END)





- Install the connecting rod cap without the connecting rod bearing installed. After tightening the connecting rod bolt to the specified torque, measure the connecting rod big end inner diameter using an inside micrometer. [1][2]Specifications.

CONNECTING ROD BUSHING OIL CLEARANCE (SMALL END)

Inner Diameter of Connecting Rod (Small End)





- Measure inner diameter of bushing. [1][2]Specifications, "Standard
and Limit"

Outer Diameter of Piston Pin





- Measure outer diameter of piston pin. [1][2]Specifications, "Standard
and Limit".

Connecting Rod Bushing Oil Clearance (Small End)





(Connecting rod small end oil clearance) = (Inner diameter of connecting rod small end) � (Outer diameter of piston pin)






- If the measured value exceeds the standard, replace the connecting rod assembly and/or piston and piston pin assembly.
- If replacing the piston and piston pin assembly, use the "Piston
Selection Table" to select the piston corresponding to the applicable bore grade of the cylinder block to be used. Service and Repair, "How to Select Piston and Bearing".

Factory Installed Parts Grading:





- Service parts apply only to piston pin grade 0 (B).





- A: Front mark
- C: Piston grade I.D. stamp
- D: Piston crown I.D. code stamp

CYLINDER BLOCK DISTORTION
- Using a scraper, remove gasket on the cylinder block surface, and also remove oil, scale, carbon, or other contamination.

CAUTION:
Be careful not to allow gasket debris to enter the oil or coolant passages.





- Measure the distortion on the block upper face at some different points in 6 directions.





- If out of the distortion limit, replace the cylinder block and lower block they are machined together as an assembly.

INNER DIAMETER OF MAIN BEARING HOUSING
- Install the main bearing caps with the main bearings removed and tighten the bolts to the specified torque. Disassembly And Assembly.





- Using a bore gauge, measure the inner diameter of the main bearing housing.





- If out of the standard, replace the cylinder block and lower cylinder block assembly.

NOTE:
These components cannot be replaced as a single unit because they were processed together.

PISTON TO CYLINDER BORE CLEARANCE

Inner Diameter of Cylinder Bore





- Using a bore gauge, measure cylinder bore for wear, out-of-round and taper at 6 different points on each cylinder. (X and Y directions at A, B and C). The Y axis is in the longitudinal direction of the engine.

NOTE:
When determining cylinder bore grade, measure cylinder bore at B position. [1][2]Specifications.
- If there are scratches and/or seizure on the cylinder inner wall, hone the inner wall.

Outer Diameter of Piston





- Measure piston skirt diameter using a micrometer. [1][2]Specifications.
- Measuring point (distance from the top): 37.5 mm (1.476 in)

Piston to Cylinder Bore Clearance
- Calculate by outer diameter of piston skirt and inner diameter of cylinder (direction X, position B).
(Clearance) = (Inner diameter of cylinder) � (Outer diameter of piston skirt).





- If it exceeds the limit, replace piston/piston pin assembly.

Reboring Cylinder Bore
1. Cylinder bore size is determined by adding piston-to-bore clearance to piston diameter "A".





2. Install lower cylinder block, and tighten to the specified torque. Otherwise, cylinder bores may be distorted in final assembly.
3. 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.
4. Hone cylinders to obtain specified piston-to-bore clearance.
5. Measure finished cylinder bore for out-of-round and taper.
- Measurement should be done after cylinder bore cools down.

OUTER DIAMETER OF CRANKSHAFT JOURNAL
- Measure outer diameter of crankshaft journals.






OUTER DIAMETER OF CRANKSHAFT PIN





- Measure outer diameter of crankshaft pin.






OUT-OF-ROUND AND TAPER OF CRANKSHAFT





- Measure the dimensions at four different points as shown on each journal and pin using a micrometer.
- Out-of-round is indicated by the difference in dimensions between
(X) and (Y) at (A) and (B).
- Taper is indicated by the difference in dimension between (A) and
(B) at (X) and (Y).






CRANKSHAFT RUNOUT





- Place a V-block on a precise flat table to support the journals on both ends of the crankshaft.
- Place a dial gauge straight up on the No. 3 journal.
- While rotating the crankshaft, read the movement of the pointer on the dial gauge, the total indicator reading.






OIL CLEARANCE OF CONNECTING ROD BEARING

Method of Measurement





- Install the connecting rod bearings to the connecting rod and the cap, and tighten the connecting rod bolts to the specified torque.
Using a inside micrometer measure the inner diameter of connecting rod bearing.
(Oil clearance) = (Inner diameter of connecting rod bearing) �
(Outer diameter of crankshaft pin)





- If clearance cannot be adjusted within the standard, grind crankshaft pin and use undersized bearing. Service and Repair, "How to
Select Piston and Bearing".

Method of Using Plastigage





- Remove oil and dust on the crankshaft pin and the surfaces of each bearing completely.
- Cut the Plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes.
- Install the connecting rod bearings to the connecting rod cap, and tighten the connecting rod bolts to the specified torque.

CAUTION:
Never rotate the crankshaft.
- Remove the connecting rod cap and bearings, and using the scale on the Plastigage bag, measure the Plastigage width.

NOTE:
The procedure when the measured value exceeds the limit is same as that described in the method by calculation.

OIL CLEARANCE OF MAIN BEARING

Method of Measurement
- Install the main bearings to the cylinder block and bearing cap. Measure the main bearing inner diameter with the bearing cap bolt tightened to the specified torque.
(Oil clearance) = (Inner diameter of main bearing) � (Outer diameter of crankshaft journal)






- If the measured value exceeds the limit, select main bearings referring to the main bearing inner diameter and crankshaft journal outer diameter, so that the oil clearance satisfies the standard. Service and Repair.

Method of Using Plastigage





- Remove oil and dust on the crankshaft journal and the surfaces of each bearing completely.
- Cut the Plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes.
- Tighten the main bearing bolts to the specified torque.

CAUTION:
Never rotate the crankshaft.
- Remove the bearing cap and bearings, and using the scale on the plastigage bag, measure the plastigage width.

NOTE:
The procedure when the measured value exceeds the limit is same as that described in the "Method by Calculation".

CRUSH HEIGHT OF MAIN BEARING





- When the bearing cap is removed after being tightened to the specified torque with main bearings installed, the tip end of bearing must protrude.





- If the standard is not met, replace main bearings.

OUTER DIAMETER OF LOWER CYLINDER BLOCK BOLT
- Perform only with M10 (0.39 in) bolts.





- Measure outer diameters (d1, d2) at two positions as shown.
- Measure d2 at a point within area A as shown.
- When the value of d1- d2 exceeds the limit (a large difference in dimensions), replace the bolt with a new one.






OUTER DIAMETER OF CONNECTING ROD BOLT





- Measure outer diameter (d) at position as shown.
- When (d) exceeds the limit (when it becomes thinner), replace the bolt with a new one.