Crankshaft Inspection
Out-of-Round and Taper
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- Remove the crankshaft from the engine block (see «CRANKSHAFT AND PISTON REMOVAL»(ref-512928-S06931802302012110400000) ).
- Remove the CKP pulse plate from the crankshaft (see «CKP PULSE PLATE REPLACEMENT»(ref-512928-S11198756592012110400000) ).
- Clean the crankshaft oil passages with pipe cleaners or a suitable brush.
- Check the keyway slot and the threaded holes for damage.
- Measure the out-of-round at the middle of each rod and main journal in two places. The difference between measurements on each journal must not be more than the service limit. Journal Out-of-Round Standard (New): 0.004 mm (0.00016 in) max. Service Limit: 0.010 mm (0.00039 in)
- Measure the taper at the edges of each rod and main journal. The difference between measurements on each journal must not be more than the service limit. Journal Taper Standard (New): 0.005 mm (0.00020 in) max. Service Limit: 0.010 mm (0.00039 in) Straightness
- Place the V-blocks on a flat surface.
- Check the total runout with the crankshaft supported on V-blocks.
- Measure the runout on all of the main journals. Rotate the crankshaft two complete revolutions. The difference between measurements on each journal must not be more than the service limit. Crankshaft Total Runout Standard (New): 0.03 mm (0.0012 in) max. Service Limit: 0.04 mm (0.0016 in)
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- Remove the pistons from the engine block (see «CRANKSHAFT AND PISTON REMOVAL»(ref-512928-S06931802302012110400000) ).
- Check the pistons for distortion or cracks.
- Measure the piston diameter at a point 13 mm (0.51 in) from the bottom of the skirt. There are two standard-size pistons (No Letter or A, and B). The letter is stamped on the top of the piston. Letters are also stamped on the engine block as the cylinder bore sizes. Piston Skirt Diameter Standard (New): No Letter (or A): 86.980-86.990 mm (3.42440-3.42480 in) B: 86.970-86.980 mm (3.42401-3.42440 in) Service Limit: No Letter (or A): 86.930 mm (3.42243 in) B: 86.920 mm (3.42204 in) Oversize Piston Skirt Diameter 0.25: 87.230-87.240 mm (3.43425-3.43464 in)
- Measure the wear and taper in direction X and Y at three levels inside each cylinder as shown. If measurements in any cylinder are beyond the oversize bore service limit, replace the engine block. If the engine block is being rebored, refer to step 7 after reboring. Cylinder Bore Size Standard (New): A or I: 87.010-87.020 mm (3.42558-3.42598 in) B or II: 87.000-87.010 mm (3.42519-3.42558 in) Service Limit: 87.070 mm (3.42795 in) Oversize Bore 0.25: 87.250-87.260 mm (3.43503-3.43543 in) Reboring Limit: 0.25 mm (0.0098 in) Bore Taper Limit (Difference between first and third measurement): 0.05 mm (0.002 in)
- Hone any scored or scratched cylinder bores (see «CYLINDER BORE HONING»(ref-512928-S02435390272012110400000) ).
- Check the top of the engine block for warpage. Measure along the edges and across the center as shown. Engine Block Warpage Standard (New): 0.07 mm (0.002 in) max.
- Calculate the difference between the cylinder bore diameter and the piston diameter. If the clearance is near or exceeds the service limit, inspect the piston and the cylinder bore for excessive wear. Piston-to-Cylinder Bore Clearance Standard (New): 0.020-0.040 mm (0.00079-0.00157 in) Service Limit: 0.05 mm (0.0020 in)
Scheme 625
- Measure the cylinder bores (see «BLOCK AND PISTON INSPECTION»(ref-512928-S39710431542012110400000) ). If the engine block is to be reused, hone the cylinders, and remeasure the bores. Only a scored or scratched cylinder bore must be honed.
- Remove the oil jets (see «ENGINE OIL GALLERY CAP REPLACEMENT»(ref-512894-S32488589812012110400000) ).
- Hone the cylinder bores with honing oil and a fine (400 grit) stone in a 60 degree cross-hatch pattern (A). NOTE: Use only a rigid hone with 400 grit or finer stone such as Sunnen, Ammco, or equivalent. Do not use stones that are worn or broken.
- When honing is complete, thoroughly clean the engine block of all metal particles. Wash the cylinder bores with hot soapy water, then dry and oil them immediately to prevent rusting. NOTE: Never use solvent, it will only redistribute the grit on the cylinder walls.
- If scoring or scratches are still present in the cylinder bores after honing to the service limit, rebore the engine block. Some light vertical scoring and scratching is acceptable if it is not deep enough to catch your fingernail, and does not run the full length of the bore.
- Install the oil jets (see «ENGINE OIL GALLERY CAP REPLACEMENT»(ref-512894-S32488589812012110400000) ).
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- Remove the piston from the engine block (see «CRANKSHAFT AND PISTON REMOVAL»(ref-512928-S06931802302012110400000) ).
- Apply new engine oil to the piston pin snap rings (A), and turn them in the ring grooves until the end gaps are lined up with the cutouts in the piston pin bores (B). NOTE: Take care not to damage the ring grooves.
- Remove the snap rings (A) from both sides of each piston. Start at the cutout in the piston pin bore. Remove the snap rings carefully so they do not go flying or get lost. Wear eye protection.
- Heat the piston and the connecting rod assembly to about 158 °F (70 °C), then remove the piston pin.
Inspection
Note. Inspect the piston, the piston pin, and the connecting rod when they are at room temperature.
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- Measure the diameter of the piston pin. Piston Pin Diameter Standard (New): 21.961-21.965 mm (0.86460-0.86476 in) Service Limit: 21.953 mm (0.86429 in)
- Zero the dial indicator (A) to the piston pin diameter.
- Check the difference between the piston pin diameter and the piston pin hole diameter in the piston. Piston Pin-to-Piston Clearance Standard (New): -0.005-0.002 mm (-0.00020-0.00008 in) Service Limit: 0.005 mm (0.00020 in)
- Measure the piston pin-to-connecting rod clearance. Piston Pin-to-Connecting Rod Clearance Standard (New): 0.005-0.015 mm (0.00020-0.00059 in) Service Limit: 0.02 mm (0.0008 in)
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- Install a piston pin snap ring (A) only on one side.
- Coat the piston pin bore in the piston, the bore in the connecting rod, and the piston pin with new engine oil.
- Heat the piston to about 158 °F (70 °C).
- Assemble the piston (A) and the connecting rod (B) with the arrow (C) and the embossed mark (D) on the same side. Install the piston pin (E).
- Install the remaining snap ring (F).
- Turn the snap rings in the ring grooves until the end gaps are positioned at the bottom of the piston.
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- Remove the piston from the engine block (see «CRANKSHAFT AND PISTON REMOVAL»(ref-512928-S06931802302012110400000) ).
- Using a ring expander (A), remove the old piston rings (B).
- Clean all ring grooves thoroughly with a squared-off broken ring or a ring groove cleaner with a blade to fit the piston grooves. The top and second ring grooves are 1.2 mm (0.047 in) wide. The second ring groove is 1.0 mm (0.039 in) wide. The oil ring groove is 2.0 mm (0.079 in) wide. File down a blade if necessary. Do not use a wire brush to clean the ring grooves, or cut the ring grooves deeper with the cleaning tools. NOTE: If the piston is to be separated from the connecting rod, do not install the new rings yet.
- Using a piston that has its rings removed, push a new ring (A) into the cylinder bore 15-20 mm (0.59-0.79 in) from the bottom.
- Measure the piston ring end-gap (B) with a feeler gauge: If the gap is too small, check to see if you have the proper rings for your engine. If the gap is too large, recheck the cylinder bore diameter against the wear limits (see «BLOCK AND PISTON INSPECTION»(ref-512928-S39710431542012110400000) ). If the bore is beyond the service limit, the engine block must be rebored. Piston Ring End-Gap Top Ring: Standard (New): 0.20-0.30 mm (0.008-0.011 in) Service Limit: 0.55 mm (0.021 in) Second Ring: Standard (New): 0.20-0.32 mm (0.008-0.012 in) Service Limit: 0.42 mm (0.016 in) Oil Ring: Standard (New): 0.20-0.50 mm (0.008-0.019 in) Service Limit: 0.55 mm (0.021 in)
- Install the top ring and the second ring as shown. The top ring (A) has a 1R mark, and the second ring (B) has a 2R mark. The manufacturing marks (C) must face upward. Piston Ring Dimensions
- After installing a new set of rings, measure the ring-to-groove clearances: Top Ring Clearance Standard (New): 0.060-0.085 mm (0.003-0.003 in) Service Limit: 0.13 mm (0.005 in) Second Ring Clearance Standard (New): 0.020-0.045 mm (0.001-0.001 in) Service Limit: 0.13 mm (0.005 in)
- Rotate the rings in their grooves to make sure they do not bind.
- Position the ring end gaps as shown.
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- Set the crankshaft to bottom dead center (BDC) for each cylinder as its piston is installed.
- Remove the connecting rod caps, then install the ring compressor, and check that the bearing is securely in place.
- Apply-new engine oil to the piston, the inside of the ring compressor, and the cylinder bore, then attach the ring compressor to the piston/connecting rod assembly.
- Position the mark (A) to face the cam chain side of the engine block.
- Position the piston in the cylinder, and tap it in using the wooden handle of a hammer (A). Push down on the ring compressor (B) to prevent the rings from expanding before entering the cylinder bore.
- Stop after the ring compressor pops free, and check the connecting rod-to-rod journal alignment before pushing the piston into place.
- Check the connecting rod bearing clearance with a plastigage (see «CONNECTING ROD BEARING REPLACEMENT»(ref-512928-S25256516512012110400000) ).
- Inspect the connecting rod bolts (see «CONNECTING ROD BOLT INSPECTION»(ref-512928-S02568789902012110400000) ).
- Apply new engine oil to the bolt threads, then install the connecting rod caps with bearings. Torque the bolts to 41 N.m (4.2 kgf.m, 30 lbf.ft).
- Tighten the connecting rod bolts an additional 120 °. NOTE: Remove the connecting rod bolt if you tightened it beyond the specified angle, and go back to step 8 of the procedure. Do not loosen it back to the specified angle. Repeat steps 1 to 10 for the remaining cylinders.
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Scheme 647
- Remove the connecting rod caps, then install the ring compressor, and check that the bearing is securely in place.
- Apply new engine oil to the piston, the inside of the ring compressor, and the cylinder bore, then attach the ring compressor to the piston/connecting rod assembly.
- Position the mark (A) to face the cam chain side of the engine block.
- Position the piston in the cylinder, and tap it in using the wooden handle of a hammer (A). Push down on the ring compressor (B) to prevent the rings from expanding before entering the cylinder bore.
- Position all pistons at top dead center (TDC).
Scheme 648
- Measure the diameter of each connecting rod bolt at point A and point B.
- Calculate the difference in diameter between point A and point B. Point A-Point B = Difference in Diameter Difference in Diameter Specification: 0-0.1 mm (0-0.004 in)
- If the difference in diameter is out of specification, replace the connecting rod bolt.