Engine Mechanical (H4DOTC) (Except Sti): Other Subaru Impreza GH

CAUTION

1. Wear appropriate work clothing, including a cap, protective goggles and protective shoes when performing any work.
2. Remove contamination including dirt and corrosion before removal, installation or disassembly.
3. Keep the disassembled parts in order and protect them from dust and dirt.
4. Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, installation, disassembly and replacement.
5. Vehicle components are extremely hot after driving. Be wary of receiving burns from heated parts.
6. Be sure to tighten fasteners including bolts and nuts to the specified torque.
7. Place shop jacks or rigid racks at the specified points.
8. Before disconnecting connectors of sensors or units, be sure to disconnect the ground cable from the battery.
9. All parts should be thoroughly cleaned, paying special attention to 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 engine 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 parts as required.
14. Even if necessary inspections have been made in advance, proceed with assembly work while making re-checks.
15. Remove or install the 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 not to stain seats and windows with coolant or oil. Place a cover over fender, 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.

1. Lift up or lower the vehicle when necessary. Make sure to support the correct positions.

GENERAL TOOL

GENERAL TOOL DESCRIPTION

PROCEDURE

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

1. V-belt
2. Timing belt
3. Camshaft
4. Cylinder head

METHOD WITH SUBARU SELECT MONITOR

1. Before checking the ignition timing, check the following item: Check the air cleaner element is free from clogging, spark plugs are in good condition, and hoses are connected properly. Check the malfunction indicator light does not illuminate.
2. Warm up the engine.
3. Read the ignition timing using Subaru Select Monitor. Ref. to «READ CURRENT DATA FOR ENGINE (NORMAL MODE)»(ref-357262-S36139671992010031100000) , OPERATION, Subaru Select Monitor.

Ignition timing [BTDC/RPM]

17°±10°/700 (AT model)

12°±10°/700 (MT model)

If the timing is not correct, check the ignition control system. Refer to "Engine Control System". Ref. to BASIC DIAGNOSTIC PROCEDURE .

Scheme 727

1. Before checking the ignition timing, check the following item: Check the air cleaner element is free from clogging, spark plugs are in good condition, and hoses are connected properly. Check the malfunction indicator light does not illuminate.
2. Warm up the engine.
3. Stop the engine, and turn the ignition switch to OFF.
4. Disconnect the ground cable from battery.
5. Remove the air intake duct. Ref. to «REMOVAL»(ref-357235-S10313590332010031100000) , Air Intake Duct.
6. Disconnect the connector from mass air flow and intake air temperature sensor.
7. Remove the air cleaner case and element.
8. Connect the timing light to the power wire of #1 ignition coil.
9. Install the connectors of air cleaner case, element, and the mass air flow and intake air temperature sensor.
10. Connect the ground cable to battery.
11. Start the engine, turn the timing light to the crank pulley, and check the ignition timing by means of crank pulley indicator.

Ignition timing [BTDC/RPM]

17°±10°/700 (AT model)

12°±10°/700 (MT model)

If the timing is not correct, check the ignition control system. Refer to "Engine Control System". Ref. to BASIC DIAGNOSTIC PROCEDURE .

FRONT SIDE BELT

1. Remove the V-belt covers.
2. Remove the air intake duct. Ref. to «REMOVAL»(ref-357235-S10313590332010031100000) , Air Intake Duct.
3. Loosen the bolt (A).
4. Loosen the slider bolt (B).
5. Remove the front side belt (C).

Scheme 728

REAR SIDE BELT

1. Remove the front side belts. Ref. to «FRONT SIDE BELT»(ref-357237-S02797211002010031100000) , REMOVAL, V-belt.
2. Cut the rear side belt with a wire cutter, etc., and discard.

Scheme 729

1. Wipe off any dust, oil and water on the groove of each pulley with cloth.
2. Install the front side belt (C), and adjust the slider bolt (B) so as to obtain the specified belt tension. Ref. to «INSPECTION»(ref-357237-S00231659292010031100000) , V-belt.
3. Tighten the bolt (A).
4. Tighten the slider bolt (B). Tightening torque: Bolt (A) 25 N.m (2.5 kgf-m, 18.4 ft-lb) Slider bolt (B) 8 N.m (0.8 kgf-m, 5.9 ft-lb)
5. Install the air intake duct. Ref. to «INSTALLATION»(ref-357235-S12040137862010031100000) , Air Intake Duct.
6. Install the V-belt cover.

Tightening torque

13 N.m (1.3 kgf-m, 9.6 ft-lb)

Scheme 730

Scheme 731

Scheme 732

Scheme 733

Scheme 734

Scheme 735

Scheme 736

Scheme 737

Scheme 738

Scheme 739

Scheme 740

Scheme 741

Scheme 742

Scheme 743

Scheme 744

Scheme 745

Scheme 746

Scheme 747

Scheme 748

Scheme 749

Scheme 750

1. Wipe off any dust, oil and water on the groove of each pulley with cloth.
2. Wipe off any oil, water, dirt, and rust on the front of the crank pulley with cloth.
3. Slowly turn the crank pulley clockwise so that the service hole of the crank pulley comes around the top. CAUTION: Do not turn the crank pulley counterclockwise.
4. Hook a new rear side belt on the A/C compressor pulley.
5. As shown in the figure, insert the claw of the belt stopper (A) to the lower hole (B) of the compressor bracket, then attach with bolt (C).
6. Place the belt guide while aligning it with the belt line of the crank pulley on the front side belt side.
7. Insert the belt guide holder into the service hole of the crank pulley so that the belt guide comes in between. NOTE: Place the belt guide holder with the longer side up.
8. Slowly turn the crank pulley clockwise until the belt guide comes to approximately 45°.
9. Place the rib surface of the rear side belt into the crank pulley groove, so that the rear side belt comes in between the belt guide holder. CAUTION: When it is difficult to place the rear side belt to the crank pulley groove, pull out the belt guide holder half way, then place the rear side belt into the groove so that it comes in between the belt guide holder.
10. Place the tool through the loop of the rear side belt, and set on the crank pulley bolt.
11. While checking the following, slowly turn the crank pulley approximately 90° clockwise so that the belt guide comes to the position shown in the figure. CAUTION: When turning the crank pulley, always make sure that the belt guide is not off from the crank pulley groove. The rib of the rear side belt is securely placed on the groove of the A/C compressor pulley. The rib of the rear side belt is securely placed on the groove of the crank pulley. The surface of the rear side belt is held by the belt stopper. The rear side belt is securely placed on the belt guide.
12. While checking the following, slowly turn the crank pulley approximately 90° clockwise so that the belt guide comes to the position shown in the figure. The rear side belt is not twisted. The rib of the rear side belt is securely placed on the groove of the A/C compressor pulley. The rib of the rear side belt is securely placed on the groove of the crank pulley. The surface of the rear side belt is held by the belt stopper. The rear side belt is securely placed on the belt guide.
13. Slowly turn the crank pulley clockwise, and install the rear side belt. CAUTION: Be careful that the total of procedures in steps 8 , 11 , 12 and 13) does not exceed 330°; failure to do so may cause damage to the rear side belt and fall of the belt guide holder.
14. Remove the belt guide and belt guide holder from the crank pulley.
15. Remove the belt stopper from the compressor bracket. CAUTION: Always remove the belt stopper; failure to do so may cause smoke, fire, or belt cutting.
16. Make sure that the belt rib is securely installed on the groove of each pulley, then turn the crank pulley slowly, twice in the clockwise direction, to seat the rear side belt properly.
17. Discard the provided tools (belt stopper, belt guide, belt guide holder, and bolt) that are used.
18. Install the front side belt. Ref. to «FRONT SIDE BELT»(ref-357237-S02797211002010031100000) , INSTALLATION, V-belt.

1. Replace the front side belt, if crack, fraying or wear is found.
2. Check the front side belt tension and adjust it if necessary by changing the generator installing position.

Front side belt tension (with belt tension gauge)

When installing new parts

640 - 780 N (65 - 80 kgf, 144 - 175 lbf)

At inspection

490 - 640 N (50 - 65 kgf, 110 - 144 lbf)

Scheme 751

Front side belt tension (without belt tension gauge)

When installing new parts

7 - 9 mm (0.276 - 0.354 in)

At inspection

9 - 11 mm (0.354 - 0.433 in)

Scheme 752

If cracks, fraying or wear is found, and when abnormal noise is produced, replace the rear side belt.

Note. Because the rear side belt is a stretch type belt, it is not necessary to check deflection and tension.

AT MODEL

1. Install the crank pulley.
2. Use the ST to secure the crank pulley, and attach the crank pulley bolts. ST 499977400 CRANK PULLEY WRENCH Clean the crankshaft thread using compressed air. Apply engine oil to the crank pulley bolt seat and thread. Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 32.5 ft-lb). Tighten the crank pulley bolts. Tightening torque: 130 N.m (13.3 kgf-m, 95.9 ft-lb)
3. Check that the tightening angle of the crank pulley bolt is 45° or more. Perform the following procedure when less than 45°. CAUTION: If the tightening angle of crank pulley bolt is less than 45°, the bolt is damaged. In this case, the bolt must be replaced. Replace the crank pulley bolts and clean them. Crank pulley bolt: Part No. 12369AA011 Clean the crankshaft thread using compressed air. Apply engine oil to the crank pulley bolt seat and thread. Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 32.5 ft-lb). Tighten the crank pulley bolts by 45° to 60°. NOTE: Conduct the tightening procedures by confirming the turning angle of crank pulley bolt referring to the gauge indicated on timing belt cover.
4. Install the V-belts. Ref. to «INSTALLATION»(ref-357237-S10596823412010031100000) , V-belt.

MT MODEL

1. Install the crank pulley.
2. Use the ST to lock the crank pulley, and attach the crank pulley bolts. ST 499977100 CRANK PULLEY WRENCH Clean the crankshaft thread using compressed air. Apply engine oil to the crank pulley bolt seat and thread. 44 Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 32.5 ft-lb). Tighten the crank pulley bolts. Tightening torque: 180 N.m (18.4 kgf-m, 132.8 ft-lb)
3. Check that the tightening angle of the crank pulley bolt is 65° or more. Perform the following procedure when less than 65°. CAUTION: If the tightening angle of crank pulley bolt is less than 65°, the bolt is damaged. In this case, the bolt must be replaced. Replace the crank pulley bolts and clean them. Crank pulley bolt: Part No. 12369AA011 Clean the crankshaft thread using compressed air. Apply engine oil to the crank pulley bolt seat and thread. 44 Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 32.5 ft-lb). Tighten the crank pulley bolts by 65° to 75°. NOTE: Conduct the tightening procedures by confirming the turning angle of crank pulley bolt referring to the gauge indicated on timing belt cover.
4. Install the V-belts. Ref. to «INSTALLATION»(ref-357237-S10596823412010031100000) , V-belt.

TIMING BELT

1. Check the timing belt teeth for breaks, cracks or wear. If any fault is found, replace the timing belt.
2. Check the condition on the back surface of the timing belt. If cracks are found, replace the timing belt.

In radial diameter h: 60 mm (2.36 in) or more

Scheme 753

AUTOMATIC BELT TENSION ADJUSTER

1. Visually check the oil seals for leaks, and rod ends for abnormal wear and scratches. If necessary, replace the automatic belt tension adjuster assembly. NOTE: Slight traces of oil at the rod oil seal does not indicate a problem.
2. Check that the adjuster rod does not move when a pressure of 165 N (16.8 kgf, 37.1 lb) is applied to it. This is to check adjuster rod stiffness.
3. If the adjuster rod is not stiff and moves freely when applying 165 N (16.8 kgf, 37.1 lb), check it using the following procedures: Slowly press the adjuster rod down to the end surface of cylinder. Repeat this operation two to three times. With the adjuster rod moved all the way up, apply a pressure of 165 N (16.8 kgf, 37.1 lb) to it, and check the adjuster rod stiffness. If the adjuster rod is not stiff and moves down, replace the automatic belt tension adjuster assembly with a new part. CAUTION: Always use a vertical type pressing tool to move the adjuster rod down. Do not use a lateral type vise. Push the adjuster rod vertically. Press-in the push adjuster rod gradually taking three minutes or more. Do not allow press pressure to exceed 9,807 N(1,000 kgf, 2,205 lb). Push in the adjuster rod to the end face of the cylinder. However, do not press the adjuster rod below the end face of the cylinder. Doing so may damage the cylinder.
4. Measure the amount of rod protrusion "H" from the end surface of the body. If it is not within specifications, replace the automatic belt tension adjuster assembly with a new part.

Amount of rod protrusion H: 5.2 - 6.2 mm (0.205 - 0.244 in)

Scheme 754

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 with a new part if faulty.
2. Check the belt tension pulley for smooth rotation. Replace the automatic belt tension adjuster assembly with a new part if abnormal noise or excessive play occurs.
3. Check the belt tension pulley for grease leakage.

BELT IDLER

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

CYLINDER HEAD

1. Check for cracks or damage. Use liquid penetrant tester on the important sections to check for fissures. Check that there are no marks of gas leaking or water leaking on gasket installing surface.
2. Measure the warping of the cylinder head surface that mates with cylinder block using a straight edge (A) and thickness gauge (B).

If the warping exceeds the limit, correct the surface by grinding it with a surface grinder.

Warping limit

0.035 mm (0.0014 in)

Grinding limit

0.3 mm (0.012 in)

Standard height of cylinder head

127.5 mm (5.02 in)

Note. Uneven torque for the cylinder head bolts can cause warpage. When reinstalling, pay special attention to the torque so as to tighten evenly.

Scheme 755

VALVE SEAT

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

Contacting width W between valve and valve seat

Standard

Intake

0.6 - 1.4 mm (0.024 - 0.055 in)

Exhaust

1.2 - 1.8 mm (0.047 - 0.071 in)

Scheme 756

Scheme 757

VALVE GUIDE

1. Check the clearance between valve guide and valve stem. The clearance can be checked by measuring respectively the outer diameter of valve stem with a micrometer and the inner diameter of valve guide with a caliper gauge. Clearance between the valve guide and valve stem: Standard Intake 0.030 - 0.057 mm (0.0012 - 0.0022 in) Exhaust 0.040 - 0.067 mm (0.0016 - 0.0026 in)
2. If the clearance between valve guide and valve stem exceeds the standard, replace the valve guide or valve itself, whichever shows the greater amount of wear or damage. 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

5.955 - 5.970 mm (0.2344 - 0.2350 in)

Exhaust

5.945 - 5.960 mm (0.2341 - 0.2346 in)

Scheme 758

Scheme 759

Scheme 760

Scheme 761

1. Place the cylinder head on ST1 with the combustion chamber upward so that valve guides fit the holes in ST1.
2. Insert the ST2 into valve guide and press it down to remove the valve guide. ST1 498267600 CYLINDER HEAD TABLE ST2 499767200 VALVE GUIDE REMOVER
3. Turn the cylinder head upside down and place the ST as shown in the figure. ST 18251AA020 VALVE GUIDE ADJUSTER
4. Before installing a new valve guide, make sure that neither scratches nor damages exist on the inner surface of valve guide holes in cylinder head.
5. Put a new valve guide, coated with sufficient oil, in the cylinder head, and 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 ST2 18251AA020 VALVE GUIDE ADJUSTER
6. Check the valve guide protrusion. Valve guide protrusion L: 15.8 - 16.2 mm (0.622 - 0.638 in)
7. Ream the inside of valve guide using ST. Put the ST in valve guide, and rotate the ST slowly clockwise while pushing it lightly. Bring the ST back while rotating it clockwise. NOTE: Apply engine oil to the ST when reaming. If the inner surface of valve guide is damaged, the edge of ST should be slightly ground with oil stone. If the inner surface of valve guide becomes lustrous and the ST does not chip, use a new ST or remedy the ST. ST 499767400 VALVE GUIDE REAMER
8. After reaming, clean the valve guide to remove chips.
9. Recheck the contact condition between valve and valve seat after replacing the valve guide.

Scheme 762

1. Inspect the flange of valve and valve stem, and replace the valve with a new part if damaged, worn, deformed, or if dimension "H" in the figure is outside of the specified limit. Head edge thickness H: Standard Intake (A) 1.0 - 1.4 mm (0.039 - 0.055 in) Exhaust (B) 1.3 - 1.7 mm (0.051 - 0.067 in)
2. Put a small amount of grinding compound on the valve seat surface, and lap the valve and valve seat surface. Replace with a new valve oil seal after lapping.

Note. It is possible to differentiate between the intake valve and the exhaust valve by their overall length.

Valve overall length

Intake

104.4 mm (4.110 in)

Exhaust

104.65 mm (4.1201 in)

VALVE SPRING

1. Check the valve springs for damage, free length, and tension. Replace the valve spring if it is not within the standard value presented in the table.
2. To measure the squareness of the valve spring, stand the valve spring on a surface plate and measure its deflection at the top of the valve spring using a try square.

VALVE SPRING REFERENCE

Scheme 763

INTAKE AND EXHAUST VALVE OIL SEAL

1. For the following, replace the oil seal with a new part. See the procedure 2) and subsequent for replacement procedures. When the lip is damaged. When the spring is out of the specified position. When readjusting the surfaces of valve and valve seat. When replacing the valve guide.
2. Place the cylinder head on ST1, and use ST2 to press-fit the oil seal.

ST1 498267600 CYLINDER HEAD TABLE

ST2 498857100 VALVE OIL SEAL GUIDE

Note. Apply engine oil to oil seal before press-fitting. When press-fitting the oil seal, do not use a hammer to strike in. The intake valve oil seals and exhaust valve oil seals are distinguished by their colors.

Color of rubber part

Intake [Gray]

Exhaust [Green]

Scheme 764

Scheme 765

Scheme 766

1. Check the valve lifter visually.
2. Measure the outer diameter of valve lifter. Outer diameter of valve lifter: 34.959 - 34.975 mm (1.3763 - 1.3770 in)
3. Measure the inner diameter of valve lifter mating surface on cylinder head. Valve lifter mating surface inner diameter: 34.994 - 35.016 mm (1.3777 - 1.3786 in)
4. Check the clearance between valve lifter and valve lifter mating surface. The clearance can be checked by measuring respectively the outer diameter of valve lifter and the inner diameter of valve lifter. If it exceeds the standard or offset wear occurs, replace the cylinder head.

Valve lifter and valve lifter mating surface clearance

Standard

0.019 - 0.057 mm (0.0007 - 0.0022 in)

CYLINDER BLOCK

1. Check for cracks or damage. Use liquid penetrant tester on the important sections to check for fissures. Check that there are no marks of gas leaking or water leaking on gasket installing surface.
2. Check the oil passages for clogging.
3. inspect the cylinder block surface that mates with cylinder head for warping by using a straight edge, and correct by grinding if necessary.

Warping limit

0.025 mm (0.00098 in)

Grinding limit

0.1 mm (0.004 in)

Standard height of cylinder block

201.0 mm (7.91 in)

Scheme 767

Scheme 768

Scheme 769

1. The cylinder bore size is stamped on the front upper face of the cylinder block. NOTE: Measurement should be performed at a temperature of 20°C (68°F). Standard sized pistons are classified into two grades, "A" and "B". These grades should be used as guide lines 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. Measure inner diameter of each cylinder. Measure the inner diameter of each cylinder in both the thrust and piston pin directions at the heights as shown in the figure, using a cylinder bore gauge. NOTE: Measurement should be performed at a temperature of 20°C (68°F). Taper: Standard 0.015 mm (0.0006 in) Out-of-roundness: Standard 0.010 mm (0.0004 in)
3. When the piston is to be replaced due to general or cylinder wear, select a suitable sized piston by measuring the piston clearance.
4. Measure outer diameter of each piston. Measure the outer diameter of each piston at the height as shown in the figure. (Thrust direction) NOTE: Measurement should be performed at a temperature of 20°C(68°F). Piston grade point H: 38.2 mm (1.50 in) Piston outer diameter: Standard A: 99.505 - 99.515 mm (3.9175 - 3.9179 in) B: 99.495 - 99.505 mm (3.9171 - 3.9175 in) 0.25 mm (0.0098 in) oversize 99.745 - 99.765 mm (3.9270 - 3.9278 in) 0.50 mm (0.0197 in) oversize 99.995 - 100.015 mm (3.9368 - 3.9376 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 - 0.010 mm (-0.00039 - 0.00039 in)
6. Boring and honing If any of the measured value of taper, out-of-roundness or cylinder-to-piston clearance is out of standard or if there is any damage on the cylinder wall, rebore it to replace with an oversize piston. CAUTION: When any of the cylinders needs reboring, all other cylinders must be bored at the same time, and replaced with oversize pistons. If the cylinder inner diameter exceeds the limit after boring and honing, replace the cylinder block. NOTE: Immediately after reboring, the cylinder diameter may differ from its real diameter due to temperature rise. Thus, when measuring the cylinder diameter, wait until it has cooled to room temperature. Cylinder inner diameter boring limit (diameter): To 100.005 mm (3.9372 in)

Scheme 770

Scheme 771

Scheme 772

1. Check the piston and piston pin for damage, 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°C (68°F). Replace if faulty. Clearance between piston hole and piston pin: 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.

Scheme 773

Scheme 774

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 marks 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. PISTON RING GAP REFERENCE - Standard mm (in) Piston ring gap Top ring 0.20 - 0.25 (0.0079 - 0.0098) Second ring 0.37 - 0.52 (0.015 - 0.020) Oil ring rail 0.20 - 0.50 (0.0079 - 0.0197)
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.

PISTON RING AND PISTON RING GROOVE CLEARANCE REFERENCE

Scheme 775

Scheme 776

Scheme 777

Scheme 778

Scheme 779

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 with bearings attached 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) CONNECTING ROD OIL CLEARANCE REFERENCE 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 (2.0447 - 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 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. Remove the bushing from connecting rod with ST and press. Press the bushing with the ST after applying oil on the periphery of new bushing. ST 499037100 CONNECTING ROD BUSHING REMOVER AND INSTALLER Make two 3 mm (0.12 in) holes in the pressed bushing to match the pre-manufactured holes on the connecting rod, then ream the inside of the bushing. After completion of reaming, clean the bushing to remove chips.

Scheme 780

Scheme 781

Scheme 782

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. Crank pin: Out-of-roundness 0.003 mm (0.0001 in) Cylindrically 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) Cylindrically 0.006 mm (0.0002 in) Grinding limit (dia.) To 59.758 mm (2.3527 in) CRANK JOURNAL DIAMETER REFERENCE Unit: mm (in) - Crank journal diameter Crank pin outer diameter #1, #3 #2, #4, #5 Standard Journal O.D. 59.992 - 60.008 (2.3619 - 2.3625) 59.992 - 60.008 (2.3619 - 2.3625) 51.984 - 52.000 (2.0466 - 2.0472) Bearing size (Thickness at center) 1.998 - 2.011 (0.0787 - 0.0792) 2.000 - 2.013 (0.0787 - 0.0793) 1.490 - 1.502 (0.0587 - 0.0591) 0.03 (0.0012) undersize Journal O.D. 59.962 - 59.978 (2.3607 - 2.3613) 59.962 - 59.978 (2.3607 - 2.3613) 51.954 - 51.970 (2.0454 - 2.0461) Bearing size (Thickness at center) 2.017 - 2.020 (0.0794 - 0.0795) 2.019 - 2.022 (0.0795 - 0.0796) 1.504 - 1.512 (0.0592 - 0.0595) 0.05 (0.0020) undersize Journal O.D. 59.942 - 59.958 (2.3599 - 2.3605) 59.942 - 59.958 (2.3599 - 2.3605) 51.934 - 51.950 (2.0447 - 2.0453) Bearing size (Thickness at center) 2.027 - 2.030 (0.0798 - 0.0799) 2.029 - 2.032 (0.0799 - 0.0800) 1.514 - 1.522 (0.0596 - 0.0599) 0.25 (0.0098) undersize Journal O.D. 59.742 - 59.758 (2.3520 - 2.3527) 59.742 - 59.758 (2.3520 - 2.3527) 51.734 - 51.750 (2.0368 - 2.0374) Bearing size (Thickness at center) 2.127 - 2.130 (0.0837 - 0.0839) 2.129 - 2.132 (0.0838 - 0.0839) 1.614 - 1.622 (0.0635 - 0.0639)
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)