Engine Mechanical (SOHC): Other Subaru Forester SG

CAUTION

1. Wear working clothing, including a cap, protective goggles, and protective shoes during operation.
2. Remove contamination including dirt and corrosion before removal, installation or disassembly.
3. Keep the disassembled parts in order and protect them from dust or dirt.
4. Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, installation, disassembly, and replacement.
5. Be careful not to burn your hands, because each part in the vehicle is hot after running.
6. Be sure to tighten fasteners including bolts and nuts to the specified torque.
7. Place shop jacks or safety stands at the specified points.
8. Before disconnecting electrical connectors of sensors or units, be sure to disconnect the ground cable from battery.
9. All parts should be thoroughly cleaned, paying special attention to the engine oil passages, pistons and bearings.
10. Rotating parts and sliding parts such as piston, bearing and gear should be coated with oil prior to assembly.
11. Be careful not to let oil, grease or coolant contact the timing belt, clutch disc and flywheel.
12. All removed parts, if to be reused, should be reinstalled in the original positions and directions.
13. Bolts, nuts and washers should be replaced with new ones as required.
14. Even if necessary inspections have been made in advance, proceed with assembly work while making rechecks.
15. Remove or install engine in an area where chain hoists, lifting devices, etc. are available for ready use.
16. Be sure not to damage coated surfaces of body panels with tools or stain seats and windows with coolant or oil. Place a cover over fenders, as required, for protection.
17. Prior to starting work, prepare the following: Service tools, clean cloth, containers to catch coolant and oil, wire ropes, chain hoist, transmission jacks, etc.
18. Lift-up or lower the vehicle when necessary. Make sure to support the correct positions.

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GENERAL PURPOSE TOOLS

GENERAL PURPOSE TOOLS

PROCEDURE

It is possible to conduct the following service procedures with engine on the vehicle, however, the procedures described in this section are based on the condition that the engine is removed from the vehicle.

1. V-belt
2. Timing Belt
3. Valve Rocker Assembly
4. Camshaft
5. Cylinder Head

FRONT SIDE BELT

Note. Perform the following procedures 1) to 4) with the engine installed to body.

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1. Remove the V-belt cover.
2. Loosen the lock bolt (A).
3. Loosen the slider bolt (B).
4. Remove the front side belt (C).

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1. Loosen the lock nut (A).
2. Loosen the slider bolt (B).
3. Remove the A/C belt.
4. Remove the A/C belt tensioner.

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1. Wipe off any oil or water on the belt and pulley.
2. Install the belt (C), and tighten the slider bolt so as to obtain the specified belt tension Refer to «INSPECTION»(ref-200788-S25611876072005102300000) , V-belt.
3. Tighten the lock bolt (A)
4. Tighten the slider bolt (B). Tightening torque: Lock bolt through bolt: 25 N.m (2.5 kgf-m, 18.1 ft-lb) Slider bolt: 8 N.m (0.8 kgf-m, 5.5 ft-lb)

Scheme 194

1. Install the belt, and tighten the slider bolt (B) so as to obtain the specified belt tension. Refer to «INSPECTION»(ref-200788-S25611876072005102300000) , V-belt.
2. Tighten the lock nut (A). Tightening torque: Lock nut (A); 22.6 N.m (2.3 kgf-m, 16.6 ft-lb)

Scheme 195

1. Replace the belts, if cracks, fraying or wear is found.
2. Check the drive belt tension and adjust it if necessary by changing the generator installing position and/or idler pulley installing position. Belt tension (A) replaced: 7 - 9 mm (0.276 - 0.354 in) reused: 9 - 11 mm (0.354 - 0.433 in) (B) replaced: 7.5 - 8.5 mm (0.295 - 0.335 in) reused: 9.0 - 10.0 mm (0.354 - 0.394 in)

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1. Remove the V-belt. Refer to «REMOVAL»(ref-200788-S33926247212005102300000) , V-belt.
2. Remove the crankshaft pulley bolt. To lock the crankshaft, use ST. ST 499977100 CRANK PULLEY WRENCH
3. Remove the crankshaft pulley.

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1. Install the crankshaft pulley.
2. Install the pulley bolt. To lock the crankshaft, use ST. ST 499977100 CRANK PULLEY WRENCH Clean the crankshaft pulley thread using an air gun. Apply engine oil to the crankshaft pulley bolt seat and thread. Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 33 ft-lb). Tighten the crankshaft pulley bolts. Tightening torque: 177 N.m (18.0 kgf-m, 130.2 ft-lb)
3. Confirm that the tightening angle of crankshaft pulley bolt is 65 degrees or more. If the tightening angle of crankshaft pulley bolt is less than 65 degrees, conduct the following procedures. Replace the crankshaft pulley bolts and clean them. Crankshaft pulley bolt: 12369AA011 Clean the crankshaft thread using an air gun. Apply engine oil to the crankshaft pulley bolt seal and thread. Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 33 ft-lb). Tighten the crankshaft pulley bolts keeping them in an angle between 65 degrees and 75 degrees. NOTE: Conduct the tightening procedures by confirming the turning angle of crankshaft pulley bolt referring to the gauge indicated on belt cover.
4. Install the A/C belt tensioner.
5. Install the A/C belt.

BELT TENSION PULLEY

1. Check the mating surfaces of timing belt and contact point of adjuster rod for abnormal wear or scratches. Replace the automatic belt tension adjuster assembly if faulty.
2. Check the tension pulley for smooth rotation. Replace if noise or excessive play is noted.
3. Check the tension pulley for grease leakage.

BELT IDLER

1. Check the belt idler for smooth rotation. Replace if noise or excessive play is noted.
2. Check the belt outer contacting surfaces of idler pulley for abnormal wear and scratches.
3. Check the belt idler for grease leakage.

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1. Remove the V-belt. Refer to «REMOVAL»(ref-200788-S33926247212005102300000) , V-belt.
2. Remove the crankshaft pulley. Refer to «REMOVAL»(ref-200788-S02022350792005102300000) , Crankshaft Pulley.
3. Remove the belt cover. Refer to «REMOVAL»(ref-200788-S33590109302005102300000) , Belt Cover.
4. Remove the timing belt assembly. Refer to «REMOVAL»(ref-200788-S26728354622005102300000) , Timing Belt Assembly.
5. Remove the camshaft position sensor. Refer to «REMOVAL»(ref-200785-S36550136562005102300000) , Camshaft Position Sensor.
6. Remove the camshaft sprocket No. 2. To lock the camshaft, use ST. ST 18231AA010 CAMSHAFT SPROCKET WRENCH NOTE: Also the CAMSHAFT SPROCKET WRENCH (499207100) can be used.
7. Remove the camshaft sprocket No. 1. To lock the camshaft, use ST. ST 499207400 CAMSHAFT SPROCKET WRENCH

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1. Install the camshaft sprocket No. 1. To lock the camshaft, use ST. ST 499207400 CAMSHAFT SPROCKET WRENCH Tightening torque: 78 N.m (8.0 kgf-m, 57.9 ft-lb) NOTE: Do not confuse the right and left side camshaft sprockets during installation. The camshaft sprocket No. 2 is identified by a projection used to monitor camshaft position sensor.
2. Install the camshaft sprocket No. 2. To lock camshaft, use ST. ST 18231AA010 CAMSHAFT SPROCKET WRENCH NOTE: Also the CAMSHAFT SPROCKET WRENCH (499207100) can be used. Tightening torque: 78 N.m (8.0 kgf-m, 57.9 ft-lb)
3. Install the camshaft position sensor. Refer to «INSTALLATION»(ref-200785-S18046523682005102300000) , Camshaft Position Sensor.
4. Install the timing belt assembly. Refer to «INSTALLATION»(ref-200788-S22789107912005102300000) , Timing Belt Assembly.
5. Install the belt cover. Refer to «INSTALLATION»(ref-200788-S41837229032005102300000) , Belt Cover.
6. Install the crankshaft pulley. Refer to «INSTALLATION»(ref-200788-S33531086162005102300000) , Crankshaft Pulley.
7. Install the V-belt. Refer to «INSTALLATION»(ref-200788-S14994437452005102300000) , V-belt.

INTAKE AND EXHAUST VALVE ROCKER SHAFT

Visually check the oil relief valve of shaft end for any of the following abnormalities.

1. Breaks in check ball body
2. Foreign particles caught in valve spring
3. Oil leakage at check ball

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1. Remove the V-belt. Refer to «INSTALLATION»(ref-200788-S14994437452005102300000) , V-belt.
2. Remove the crankshaft pulley. Refer to «REMOVAL»(ref-200788-S02022350792005102300000) , Crankshaft Pulley.
3. Remove the belt cover. Refer to «REMOVAL»(ref-200788-S33590109302005102300000) , Belt Cover.
4. Remove the timing belt assembly. Refer to «REMOVAL»(ref-200788-S26728354622005102300000) , Timing Belt Assembly.
5. Remove the camshaft sprocket. Refer to «REMOVAL»(ref-200788-S15205751072005102300000) , Camshaft Sprocket.
6. Remove the crankshaft sprocket. Refer to «REMOVAL»(ref-200788-S17799025592005102300000) , Crankshaft Sprocket.
7. Remove the belt cover No. 2 (LH).
8. Remove the belt cover No. 2 (RH). NOTE: Do not damage or lose the seal rubber when removing belt covers.
9. Remove the tensioner bracket.
10. Remove the camshaft position sensor support. (LH side only)
11. Remove the oil level gauge guide. (LH side only)
12. Remove the valve rocker assembly. Refer to «REMOVAL»(ref-200788-S05968100162005102300000) , Valve Rocker Assembly.
13. Remove the camshaft cap. Remove the bolts (a) through (b) in alphabetical sequence. Equally loosen the bolts (c) through (j) all the way in alphabetical sequence. Remove the bolts (k) through (p) in alphabetical sequence using ST. ST 499497000 TORX PLUS Remove the camshaft cup.
14. Remove the camshaft.
15. Remove the oil seal.
16. Remove the plug from rear side of camshaft. CAUTION: Do not remove the oil seal unless necessary. Do not scratch the journal surface when removing oil seal.

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1. Apply a coat of engine oil to the camshaft journals, and then install the camshaft.
2. Install the camshaft cap. Apply liquid gasket on the around of camshaft cap. Liquid gasket: THREE BOND 1280B P/N K0877YA018 NOTE: Apply a coat of 3 mm (0.12 in) dia (A), liquid gasket along edge (B) of the camshaft cap (C) mating surface. Temporarily tighten the bolts (g) through (j) in alphabetical sequence. Install the valve rocker assembly. Tighten the bolts (a) through (h) in alphabetical sequence. Tightening torque: 25 N.m (2.5 kgf-m, 18.1 ft-lb) Tighten the TORX bolts (i) through (n) in alphabetical sequence using ST. ST 499497000 TORX PLUS Tightening torque: 18 N.m (1.8 kgf-m, 13.0 ft-lb) Tighten the bolts (o) through (v) in alphabetical sequence. Tightening torque: 10 N.m (1.0 kgf-m, 7.2 ft-lb) Tighten the bolts (w) through (x) in alphabetical sequence. Tightening torque: 10 N.m (1.0 kgf-m, 7.2 ft-Ib)
3. Apply a coat of grease to oil seal lips, and then install the oil seal (A) on camshaft using ST1 and ST2. NOTE: Use a new oil seal. ST1 499597000 OIL SEAL GUIDE ST2 499587500 OIL SEAL INSTALLER
4. Install the plug using ST. ST 499587700 CAMSHAFT OIL SEAL INSTALLER
5. Adjust the valve clearance. Refer to «ADJUSTMENT»(ref-200788-S04776595562005102300000) , Valve Clearance.
6. Install the rocker cover and connect PCV hose.
7. Install the oil level gauge guide. (LH side only)
8. Install the camshaft position sensor support. (LH side only)
9. Install the tensioner bracket. Tightening torque: 25 N.m (2.5 kgf-m, 18.1 ft-lb)
10. Install the belt cover No. 2 (RH). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
11. Install the belt cover No. 2 (LH). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
12. Install the crankshaft sprocket. Refer to «INSTALLATION»(ref-200788-S33116162442005102300000) , Crankshaft Sprocket.
13. Install the camshaft sprocket. Refer to «INSTALLATION»(ref-200788-S00049029912005102300000) , Camshaft Sprocket.
14. Install the timing belt assembly. Refer to «INSTALLATION»(ref-200788-S22789107912005102300000) , Timing Belt Assembly.
15. Install the belt cover. Refer to «INSTALLATION»(ref-200788-S41837229032005102300000) , Belt Cover.
16. Install the crankshaft pulley. Refer to «INSTALLATION»(ref-200788-S33531086162005102300000) , Crankshaft Pulley.
17. Install the V-belt. Refer to «INSTALLATION»(ref-200788-S14994437452005102300000) , V-belts

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1. Measure the bend, and repair or replace if necessary. Limit: 0.025 mm (0.0010 in)
2. Check the journal for damage and wear. Replace if faulty.
3. Measure the outside diameter of camshaft journal and inside diameter of cylinder head journal, and determine the difference between two (= oil clearance). If the oil clearance exceeds specifications, replace the camshaft or cylinder head as necessary.
4. Check the cam face condition; remove the minor faults by grinding with oil stone. Measure the cam height H; replace if the limit has been exceeded. Cam height: H Cam base circle diameter A: IN: 34.00 mm (1.3386 in) EX: 34.00 mm (1.3386 in)

CAMSHAFT SUPPORT

Measure the thrust clearance of camshaft with dial gauge. If the clearance exceeds the limit, replace the camshaft support.

Standard

1. 0.030 - 0.090 mm (0.0012 - 0.0035 in)

Limit

1. 0.10 mm (0.0039 in)

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1. Remove the V-belt. Refer to «REMOVAL»(ref-200788-S33926247212005102300000) , V-belt.
2. Remove the crankshaft pulley. Refer to «REMOVAL»(ref-200788-S02022350792005102300000) , Crankshaft Pulley.
3. Remove the belt cover. Refer to «REMOVAL»(ref-200788-S33590109302005102300000) , Belt Cover.
4. Remove the timing belt assembly. Refer to «REMOVAL»(ref-200788-S26728354622005102300000) , Timing Belt Assembly.
5. Remove the camshaft sprocket. Refer to «REMOVAL»(ref-200788-S15205751072005102300000) , Camshaft Sprocket.
6. Remove the intake manifold. Refer to «REPLACEMENT»(ref-200790-S26176006012005102300000) , Engine Coolant.
7. Remove the bolt which installs A/C compressor bracket on cylinder head.
8. Remove the valve rocker assembly. Refer to «REMOVAL»(ref-200788-S05968100162005102300000) , Valve Rocker Assembly.
9. Remove the camshaft. Refer to «REMOVAL»(ref-200788-S34305507602005102300000) , Camshaft.
10. Remove the cylinder head bolts in alphabetical sequence shown in the figure. NOTE: Leave the bolts (a) and (c) engaged by three or four threads to prevent cylinder head from falling.
11. While tapping the cylinder head with a plastic hammer, separate it from cylinder block.
12. Remove the bolts (a) and (c) to remove cylinder head.
13. Remove the cylinder head gasket. CAUTION: Do not scratch the mating surface of cylinder head and cylinder block.
14. Similarly, remove the right side cylinder head.

Scheme 228

1. Install the cylinder head and gaskets on cylinder block. CAUTION: Use new cylinder head gaskets. Be careful not to scratch the mating surface of cylinder block and cylinder head.
2. Tighten the cylinder head bolts. Apply a coat of engine oil to the washers and bolt threads. Tighten all bolts to 29 N.m (3.0 kgf-m, 22 ft-lb) in alphabetical sequence. Then tighten all bolts to 69 N.m (7.0 kgf-m, 51 ft-lb) in alphabetical sequence. Back off all bolts in reverse order of assembly by 180° first; back them off by 180° again. Tighten the bolts (a) and (b) to 34 N.m (3.5 kgf-m, 25 ft-lb). Tighten the bolts (c), (d), (e) and (f) to 15 N.m (1.5 kgf-m, 11 ft-lb). Tighten all bolts by 80 to 90° in alphabetical sequence. CAUTION: Do not tighten bolts more than 90°. Further tighten all bolts by 80 to 90° in alphabetical sequence shown in figure below. CAUTION: Ensure that the total "re-tightening angle" [in the former two steps], do not exceed 180°.
3. Install the camshaft. Refer to «INSTALLATION»(ref-200788-S22142287432005102300000) , Camshaft.
4. Install the valve rocker assembly. Refer to «INSTALLATION»(ref-200788-S30965931322005102300000) , Valve Rocker Assembly.
5. Install the A/C compressor bracket on cylinder head.
6. Install the intake manifold. Refer to «INSTALLATION»(ref-200785-S13124992952005102300000) , Intake Manifold.
7. Install the camshaft sprocket. Refer to «INSTALLATION»(ref-200788-S00049029912005102300000) , Camshaft Sprocket .
8. Install the timing belt assembly. Refer to «INSTALLATION»(ref-200788-S22789107912005102300000) , Timing Belt Assembly.
9. Install the belt cover. Refer to «INSTALLATION»(ref-200788-S41837229032005102300000) , Belt Cover.
10. Install the crankshaft pulley. Refer to «INSTALLATION»(ref-200788-S33531086162005102300000) , Crankshaft Pulley.
11. Install the V-belt. Refer to «INSTALLATION»(ref-200788-S14994437452005102300000) , V-belt.

INTAKE AND EXHAUST VALVE OIL SEAL

Replace the oil seal with new one, if lip is damaged or spring out of place, or when the surfaces of intake valve and valve seat are reconditioned or intake valve guide is replaced. Use pliers to pinch and remove oil seal from valve.

1. Place the cylinder head on ST1.
2. Press-fit oil seal to the specified dimension indicated in the figure using ST2.

ST1 498267800 CYLINDER HEAD TABLE

ST2 498857100 VALVE OIL SEAL GUIDE

Color of rubber part

1. Intake [Black]
2. Exhaust [Brown]

Color of spring part

1. Intake [Silver]
2. Exhaust [Silver]

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1. Make sure that no crack or other damage exists. In addition to visual inspection, inspect important areas by means of red lead check. Also make sure that gasket installing surface shows no trace of gas and water leaks.
2. Place the cylinder head on ST. ST 498267800 CYLINDER HEAD TABLE
3. Measure the warping of the cylinder head surface that mates with crankcase using a straight edge and thickness gauge. If the warping exceeds 0.05 mm (0.0020 in), re-grind the surface with a surface grinder. Warping limit: 0.05 mm (0.0020 in) Grinding limit: 0.1 mm (0.004 in) Standard height of cylinder head: 97.5 mm (3.839 in) NOTE: Uneven torque for the cylinder head bolts can cause warping. When reassembling, pay special attention to the torque so as to tighten evenly.

VALVE SEAT

Inspect the intake and exhaust valve seats, and then correct the contact surfaces with valve seat cutter if they are defective or when valve guides are replaced.

Valve seat width: W

1. Intake (A) Standard 1.1 mm (0.043 in)
2. Limit 1.8 mm (0.071 in)
3. Exhaust (B) Standard 1.5 mm (0.059 in)
4. Limit 2.2 mm (0.087 in)

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1. Check the clearance between valve guide and stem. The clearance can be checked by measuring the outside diameter of valve stem and the inside diameter of valve guide with outside and inside micrometers respectively. Clearance between the valve guide and valve stem: Standard Intake 0.035 - 0.062 mm (0.0014 - 0.0024 in) Exhaust 0.040 - 0.067 mm (0.0016 - 0.002) Limit 0.15 mm (0.0059 in)
2. If the clearance between valve guide and stem exceeds the limit, replace the valve guide or valve itself whichever shows greater amount of wear. See the following procedure for valve guide replacement. Valve guide inner diameter: 6.000 - 6.012 mm (0.2362 - 0.2367 in) Valve stem outer diameters: Intake 5.950 - 5.965 mm (0.2343 - 0.2348 in) Exhaust 5.945 - 5.960 mm (0.2341 - 0.2346 in) Place the cylinder head on ST1 with the combustion chamber upward so that valve guides enter the holes in ST1. Insert the ST2 into valve guide and press it down to remove valve guide. ST1 498267800 CYLINDER HEAD TABLE ST2 499767200 VALVE GUIDE REMOVER Turn the cylinder head upside down and Place ST as shown in the figure. Intake side: ST 499767700 VALVE GUIDE ADJUSTER Exhaust side: ST 499767800 VALVE GUIDE ADJUSTER Before installing new oversize valve guide, make sure that neither scratches nor damages exist on the inside surface of valve guide holes in cylinder head. Put new valve guide, coated with sufficient oil, in the cylinder, and then insert the ST1 into valve guide. Press in until the valve guide upper end is flush with the upper surface of ST2. ST1 499767200 VALVE GUIDE REMOVER Intake side: ST2 499767700 VALVE GUIDE ADJUSTER Exhaust side: ST2 499767800 VALVE GUIDE ADJUSTER Check the valve guide protrusion. Valve guide protrusion: L Intake 20.0 - 20.5 mm (0.787 - 0.807 in) Exhaust 16.5 - 17.0 mm (0.650 - 0.669 in) Ream the inside of valve guide with ST. Gently rotate the reamer clockwise while pressing it lightly into valve guide, and return it also rotating clockwise. After reaming, clean the valve guide to remove chips. CAUTION: Apply engine oil to the reamer when reaming. If the inner surface of the valve guide is torn, the edge of the reamer should be slightly ground with an oil stone. If the inner surface of the valve guide becomes lustrous and the reamer does not chips, use a new reamer or remedy the reamer. ST 499767400 VALVE GUIDE REAMER Recheck the contact condition between valve and valve seat after replacing valve guide.

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1. Inspect the flange and stem of valve, and replace if damaged, worn, or deformed, or if "H" is less than the specified limit. H: Intake Standard 1.0 mm (0.039 in) Limit 0.6 mm (0.024 in) Exhaust Standard 1.2 mm (0.047 in) Limit 0.6 mm (0.024 in) Valve overall length: Intake 120.6 mm (4.75 in) Exhaust 121.7 mm (4.79 in) Put a small amount of grinding compound on the seat surface and lap the valve and seat surface. Refer to «VALVE SEAT»(ref-200788-S01443969452005102300000) , Cylinder Head Assembly. Install a new intake valve oil seal after lapping.

CYLINDER BLOCK

1. Visually check for cracks and damage. Especially, inspect the important parts by means of red lead check.
2. Check the oil passages for clogging.
3. Inspect the crankcase surface that mates with cylinder head for warping by using a straight edge, and correct by grinding if necessary.

Warping limit

1. 0.05 mm (0.0020 in)

Grinding limit

1. 0.1 mm (0.004 in)

Standard height of cylinder block

1. 201.0 mm (7.91 in)

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1. The cylinder bore size is stamped on cylinder block's front upper surface. NOTE: Measurement should be performed at a temperature 20°C (68°F). Standard sized pistons are classified into two grades, "A" and "B". These grades should be used as a guide line in selecting a standard piston. Standard diameter: A: 99.505 - 99.515 mm (3.9175 - 3.9179 in) B: 99.495 - 99.505 mm (3.9171 - 3.9175 in)
2. How to measure the inner diameter of each cylinder Measure the inner diameter of each cylinder in both the thrust and piston pin directions at the heights shown in the figure, using a cylinder bore gauge. NOTE: Measurement should be performed at a temperature 20°C (68°F). Taper: Standard 0.015 mm (0.0006 in) Limit 0.050 mm (0.0020 in) Out-of-roundness: Standard 0.010 mm (0.0004 in) Limit 0.050 mm (0.0020 in)
3. When the piston is to be replaced due to general or cylinder wear, determine a suitable sized piston by measuring the piston clearance.
4. How to measure the outer diameter of each piston. Measure the outer diameter of each piston at the height shown in the figure. (Thrust direction) NOTE: Measurement should be performed at a temperature of 20°C (68°F). Piston grade point H: 37.0 mm (1.457 in) Piston outer diameter: Standard A: 99.485 - 99.495 mm (3.9167 -3.9171 in) B: 99.475 - 99.485 mm (3.9163 - 3.9167 in) 0.25 mm (0.0098 in) oversize 99.725 - 99.735 mm (3.9262 - 3.9266 in) 0.50 mm (0.0197 in) oversize 99.975 - 99.985 mm (3.9360 - 3.9364 in)
5. Calculate the clearance between cylinder and piston. NOTE: Measurement should be performed at a temperature of 20°C (68°F). Cylinder to piston clearance at 20°C (68°F): Standard 0.010 - 0.030 mm (0.0004 - 0.0012 in) Limit 0.050 mm (0.0020 in)
6. Boring and honing If the value of taper, out-of-roundness, or cylinder-to-piston clearance measured exceeds the specified limit or if there is any damage on the cylinder wall, rebore it to use an oversize piston. CAUTION: When any of the cylinders needs reboring, all other cylinders must be bored at the same time, and use oversize pistons. Do not perform boring on one cylinder only, nor use an oversize piston for one cylinder only. If the cylinder inner diameter exceeds the limit after boring and honing, replace the crankcase. NOTE: Immediately after reboring, the cylinder diameter 1 may differ from its real diameter due to temperature rise. Thus, pay attention to this when measuring the cylinder diameter. Limit of cylinder enlarging (boring): 0.5 mm (0.020 in)

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1. Check the pistons and piston pins for damage, cracks, and wear and the piston ring grooves for wear and damage. Replace if defective.
2. Measure the piston-to-cylinder clearance at each cylinder. Refer to «CYLINDER AND PISTON»(ref-200788-S21787645912005102300000) , Cylinder Block. If any of the clearances is not to specification, replace the piston or bore the cylinder to use an oversize piston.
3. Make the sure that piston pin can be inserted into piston pin hole with a thumb at 20°C (68°F). Replace if defective. Standard clearance between piston pin and hole in piston: Standard 0.004 - 0.008 mm (0.0002 - 0.0003 in) Limit 0.020 mm (0.0008 in)
4. Check the circlip installation groove on piston for burr (A). If necessary, remove the burr from groove so that piston pin can lightly move.
5. Check the piston pin circlip for distortion, cracks and wear.

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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 one of the same size as the piston. CAUTION: Marks are shown on the end of top and second rings. When installing the rings to piston, face these marks upward. Oil ring is composed of upper rail, expander and lower rail. Be careful of the rail direction when installing oil ring to the piston.
2. Clean the piston ring groove and piston ring.
3. Squarely place the piston ring and oil ring in cylinder, and then measure the piston ring gap with a thickness gauge.
4. Measure the clearance between piston ring and piston ring groove with a thickness gauge.

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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 crankshaft, and then measure the side clearance (thrust clearance). Replace the connecting rod if the side clearance exceeds the specified limit. Connecting rod side clearance: Standard 0.070 - 0.330 mm (0.0028 - 0.0130 in) Limit 0.4 mm (0.016 in)
4. Inspect the connecting rod bearing for scar, peeling, seizure, melting, wear, etc.
5. Measure the oil clearance on individual connecting rod bearings by means of plastic gauge. If any oil clearance is not within specification, replace the defective bearing with a new one of standard size or undersize as necessary. (See the table below.) Connecting rod oil clearance: Standard 0.012 - 0.038 mm (0.0005 - 0.0015 in) Limit 0.05 mm (0.0020 in) OIL CLEARANCE Unit: mm (in) Bearing Bearing size (Thickness at center) Outer diameter of crank pin Standard 1.490 - 1.502 (0.0587 - 0.0591) 51.984 - 52.000 (2.0466 - 2.0472) 0.03 (0.0012) undersize 1.504 - 1.512 (0.0592 - 0.0595) 51.954 - 51.970 (2.0454 - 2.0461) 0.05 (0.0020) undersize 1.514 - 1.522 (0.0596 - 0.0599) 51.934 - 51.950 (2.0446 - 2.0453) 0.25 (0.0098) undersize 1.614 - 1.622 (0.0635 - 0.0639) 51.734 - 51.750 (2.0368 - 2.0374)
6. Inspect the bushing at connecting rod small end, and replace if worn or damaged. Also measure the piston pin clearance at connecting rod small end. Clearance between piston pin and bushing: Standard 0 - 0.022 mm (0 - 0.0009 in) Limit 0.030 mm (0.0012 in)
7. Replacement procedure is as follows. Remove the bushing from connecting rod with ST and press. Press the bushing with ST after applying oil on the periphery of bushing. ST 499037100 CONNECTING ROD BUSHING REMOVER AND INSTALLER Make two 3 mm (0.12 in) holes in bushing. Ream the inside of bushing. After the completion of reaming, clean the bushing to remove chips.

Scheme 257

Scheme 258

Scheme 259

Scheme 260

Scheme 261

1. Clean the crankshaft completely and check for cracks by means of red lead check etc., and replace if defective.
2. Measure the crankshaft bend, and correct or replace if it exceeds the limit. NOTE: If a suitable V-block is not available, install the #1 and #5 crankshaft bearing on cylinder block, position the crankshaft on these bearings and 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 specifications, replace the bearing with a suitable (undersize) one, and then replace or recondition the crankshaft as necessary. When grinding the crank journal or crank pin, finish them to specified dimensions according to the undersize bearing to be used. Crank pin and crank journal: Out-of-roundness 0.020 mm (0.0008 in) or less Taper limit 0.07 mm (0.0028 in) Grinding limit 0.250 mm (0.0098 in)
4. Measure the thrust clearance of crankshaft at center bearing. If the clearance exceeds the limit, replace bearing. Crankshaft thrust clearance: Standard 0.030 - 0.115 mm (0.0012 - 0.0045 in) Limit 0.25 mm (0.0098 in)
5. Inspect the individual crankshaft bearings for signs of flaking, seizure, melting, and wear.
6. Measure the oil clearance on each crankshaft bearing by means of plastigauge. If the measurement is not within the specification, replace the defective bearing with an undersize one, and then replace or recondition the crankshaft as necessary.