Part 2
PISTON AND PISTON PIN1. Check the piston and piston pin for breaks, cracks or wear. Replace if faulty.
2. Check the piston ring groove for wear and damage. Replace if faulty.
3. Make sure that the piston pin can be inserted into the piston pin hole with a thumb at 20 degrees (68 degrees F). Replace if faulty.
Standard clearance between piston pin and hole in piston:
Standard 0.004 - 0.008 mm (0.0002 - 0.0003 in)
4. Check the snap ring installation groove (A) on the piston for burr. If necessary, remove burr from the groove so that the piston pin can lightly move.
5. Check the piston pin snap ring for distortion, cracks and wear.
PISTON RING
1. If the piston ring is broken, damaged or worn, or if its tension is insufficient, or when the piston is replaced, replace the piston ring with a new part of the same size as piston.
NOTE:
^ The top ring and second ring have the mark to determine the direction for installing. When installing the ring to piston, face this mark to the top side.
^ Oil ring consists of the upper rail, expander and lower rail. When installing oil ring on piston, be careful of the direction of each rail.
2. Using the piston, insert the piston ring and oil ring into the cylinder so that they are perpendicular to the cylinder wall, and measure the piston ring gap with a thickness gauge.
3. Fit the piston ring straight into the piston ring groove, then measure the clearance between piston ring and piston ring groove with a thickness gauge.
NOTE: Before measuring the clearance, clean the piston ring groove and piston ring.
CONNECTING ROD
1. Replace the connecting rod, if the large or small end thrust surface is damaged.
2. Check for bend or twist using a connecting rod aligner. Replace the connecting rod if the bend or twist exceeds the limit.
Limit of bend or twist per 100 mm (3.94 in) in length: 0.10 mm (0.0039 in)
3. Install the connecting rod fitted with bearing to the crankshaft, and measure the thrust clearance using a thickness gauge. If the thrust clearance exceeds the standard or uneven wear is found, replace the connecting rod.
Connecting rod thrust clearance:
Standard 0.070 - 0.330 mm (0.0028 - 0.0130 in)
4. Inspect the connecting rod bearing for scar, peeling, seizure, melting, wear, etc.
5. Measure the oil clearance on each connecting rod bearing using plastigauge. If any oil clearance is not within the standard, replace the defective bearing with a new part of standard size or undersize as necessary.
Connecting rod oil clearance:
Standard 0.017 - 0.045 mm (0.0007 - 0.0018 in)
6. Inspect the bushing at connecting rod small end, and replace with a new part if worn or damaged.
7. Measure the piston pin clearance at connecting rod small end. If the measured value is not within the standard, replace it with a new part.
Clearance between piston pin and bushing:
Standard 0 - 0.022 mm (0 - 0.0009 in)
8. The replacement procedure for the connecting rod small end bushing is as follows.
1. Remove the bushing from connecting rod with ST and press.
2. Press the bushing with the ST after applying oil on the periphery of new bushing.
ST 499037100 CONNECTING ROD BUSHING REMOVER AND INSTALLER
3. Make two 3 mm (0.12 in) holes in the pressed bushing by aligning with the pre-manufactured holes on the connecting rod, and ream the inside of the bushing.
4. After completion of reaming, clean the bushing to remove chips.
CRANKSHAFT AND CRANKSHAFT BEARING
1. Clean the crankshaft completely, and check it for cracks using liquid penetrant tester. If defective, replace the crankshaft.
2. Measure warping of the crankshaft. If it exceeds the limit, correct or replace it.
NOTE: If a suitable V-block is not available, using just the #1 and #5 crankshaft bearings on cylinder block, position the crankshaft on cylinder block. Then, measure the crankshaft bend using a dial gauge.
Crankshaft bend limit. 0.035 mm (0.0014 in)
3. Inspect the crank journal and crank pin for wear. If they are not within the standard, replace the bearing with a suitable (undersize) one, and replace or grind to correct the crankshaft as necessary. When grinding the crank journal or crank pin, finish them to the specified dimensions according to the undersize bearing to be used.
Crankpin:
Out-of-roundness 0.003 mm (0.0001 in)
Cylindricality 0.004 mm (0.0002 in)
Grinding limit (dia.) To 51.750 mm (2.0374 in)
Crank journal.
Out-of-roundness 0.005 mm (0.0002 in)
Cylindricality 0.006 mm (0.0002 in)
Grinding limit (dia.) To 59.758 mm (2.3527 in)
4. Use a thickness gauge to measure the thrust clearance of crankshaft at #5 crank journal bearing. If clearance exceeds the standard, replace the bearing.
Crankshaft thrust clearance:
Standard 0.030 - 0.115 mm (0.0012 - 0.0045 in)
5. Inspect individual crankshaft bearings for signs of flaking, seizure, melting and wear.
6. Measure the oil clearance on each crankshaft bearing using plastigauge. If the measured value is out of standard, replace the defective bearing with an undersize one, and replace or grind to correct the crankshaft as necessary.
Crankshaft oil clearance:
Standard 0.010 - 0.030 mm (0.0004 - 0.0012 in)