Crankshaft and Cylinder Block
CRANKSHAFT AND CYLINDER BLOCKREMOVAL AND INSTALLATION
Removal Steps 1-8:
Required Special tools:
^ MB991514: Angle Gauge
REMOVAL SERVICE POINT
[[A]] CRANKSHAFT REMOVAL
After removing the crankshaft with the crankshaft sensing ring attached, temporarily place it on a V-block to prevent teeth of the sensing ring from deforming.
NOTE: If a tooth bends, be sure to replace the crankshaft sensing ring with a new one.
INSTALLATION SERVICE POINTS
]]A[[ CRANKSHAFT SENSING RING INSTALLATION
Tighten crankshaft sensing ring bolts to the torque of 11 ± 1 Nm in the tightening order shown in the illustration.
]]B[[ THRUST BEARING INSTALLATION
1. Install the thrust bearing on the Number 3 bearing on the cylinder block side. Application of engine oil makes the installation easier.
2. Install the thrust bearing so that the grooved side is on the crankshaft weight side.
]]C[[ CRANKSHAFT BEARING UPPER INSTALLATION
1. When replacing the crankshaft bearing upper, select a bearing with the size corresponding to the Cylinder block journal diameter in the table below.
2. The crankshaft bearing upper has an identification color or identification mark at the illustrated position.
3. Install the selected crankshaft bearing upper.
]]D[[ CRANKSHAFT BEARING LOWER INSTALLATION
1. When replacing the crankshaft bearing lower, select a bearing with the size corresponding to the crankshaft journal diameter in the table below.
2. The crankshaft bearing lower has an identification color or identification mark at the illustrated position.
3. Install the selected crankshaft bearing lower.
]]E[[ CRANKSHAFT BEARING CAP / CRANKSHAFT BEARING CAP BOLT INSTALLATION
1. Install the crankshaft bearing cap with reference to the identification mark as illustrated.
2. Make sure that the underhead length of the bolt is at or below the limit before installing the crankshaft bearing cap bolt. If the length exceeds the limit, replace the bolt with a new one.
Limit: 75.5 - 76.5 mm (2.972 - 3.012 inch)
3. Apply engine oil to the threaded portion and seat surface of the bolt.
4. Tighten crankshaft bearing cap bolts to the torque of 26.5 ± 2.0 Nm (20 ± 1 ft-lb) according to the tightening order.
CAUTION
^ When the tightening angle is smaller than the specified tightening angle, the appropriate tightening capacity cannot be secured.
^ When the tightening angle is larger than the specified tightening angle, remove the bolt to start from the beginning again according to the procedure.
5. Use special tool MB991614 to tighten bolts 45° according to the tightening order.
6. Check end play of the crankshaft after installing the crankshaft bearing cap. If the end play exceeds the limit, replace the thrust bearing.
Standard value: 0.05 - 0.25 mm (0.002 - 0.010 inch)
Limit: 0.4 mm (0.016 inch)
INSPECTION
CRANKSHAFT OIL CLEARANCE (PLASTIGAGE METHOD)
Oil clearance can be easily measured by using a "plastigage." When using a "plastigage," perform measurement in the following procedure.
1. Fully wipe oil off the outside diameter of the crankshaft and inside diameter of the bearing.
2. Assemble the crankshaft.
3. Place a plastigage in length equal to the bearing width on the journal shaft straight in alignment with the shaft center.
4. Carefully install the bearing cap and tighten the bolt according to the main point of installation ]]B[[.
5. Remove the bolt, and then carefully remove the crankshaft bearing cap.
6. Measure the crushed plastigage width (area most widely crushed) using a scale printed on the plastigage bag.
Standard value: 0.012 - 0.030 mm (0.0005 - 0.0012 inch)
Limit: 0.1 mm (0.004 inch)
CYLINDER BLOCK
1. Visually check the cylinder block for scratch, rust and corrosion. Use a flaw detecting agent to check for cracks. If it is found faulty, repair or replace it.
2. Measure distortion on the top surface of the cylinder block using a straight edge and thickness gauge. If distortion exceeds the limit, grind and repair it. A gasket or the like must not be adhered to the top surface of the cylinder block during measurement.
Distortion on bottom
Limit: Within 0.05 mm (0.0020 inch)
Grinding limit: 0.2 mm (0.008 inch)
3. Check the cylinder wall for scratch or seizure. If there is any defect, replace the cylinder block.
4. Measure the bore and cylindricity of the cylinder using a cylinder gauge. If the cylinder is excessively worn, repair the cylinder and replace the piston and piston rings. Measuring points are as shown in the illustration.
Standard value
Cylinder bore: 86.0 mm (3.39 inches)
Cylindricity: 0.15 mm (0.006 inch)