Main Bearings, Crankshaft and Cylinder Block
CRANKSHAFT RUNOUT
Using a dial gauge, measure runout at center journal. Rotate crankshaft slowly. If runout exceeds its limit, replace crankshaft.
Limit on runout: 0.06 mm (0.0023 inch)
CRANKSHAFT THRUST PLAY
Measure this play with crankshaft set in cylinder block in the normal manner, that is, with thrust bearing and journal bearing caps installed.
Use a dial gauge to read displacement in axial (thrust) direction of crankshaft. If its limit is exceeded, replace thrust bearing with new standard one or oversize one to obtain standard thrust play.
Crankshaft Thrust Play:
Standard: 0.11 - 0.31 mm (0.0044- 0.0122 inch)
Limit: 0.38 mm (0.0149 inch)
Thickness Of Crankshaft Thrust Bearing:
Standard: 2.500 mm (0.0984 inch)
Oversize 0.125 mm (0.0049 inch): 2.563 mm (0.1009 inch)
OUT-OF-ROUND AND TAPER (UNEVEN WEAR) OF JOURNALS
An unevenly worn crankshaft journal shows up as a difference in diameter at a cross section or along its length (or both). This difference, if any, is determined by taking micrometer readings. If any one of journals is badly damaged or if amount of uneven wear in the sense explained above exceeds its limit, regrind or replace crankshaft.
Limit On Out-of-Round And Taper: 0.01 mm (0.0004 inch)
MAIN BEARINGS
General Information
^ Service main bearings are available in standard size and 0.25 mm (0.0098 inch) undersize, and each of them has five kinds of bearings differing in tolerance.
^ Upper half of bearing has oil groove as shown in figure. Install this half with oil groove to cylinder block.
^ On each main bearing cap, arrow mark and number are embossed as shown in figure. When installing each bearing cap to cylinder block, point arrow mark toward crankshaft pulley side and install each cap from that side to flywheel side in ascending order of numbers " 1", "2", "3", "4" and "5." Tighten cap bolts to specified torque.
Inspection
Check bearings for pitting, scratches, wear or damage. If any malcondition is found, replace both upper and lower halves. Never replace one half without replacing the other half.
MAIN BEARING CLEARANCE
Check clearance by using gaging plastic according to following procedure:
1. Remove bearing caps.
2. Clean bearings and main journals.
3. Place a piece of gaging plastic the full width of bearing (parallel to crankshaft) on journal, avoiding oil hole.
4. Install bearing cap as previously outlined and evenly toque cap bolts to specified torque. Bearing cap MUST be torqued to specification in order to assure proper reading of clearance.
Tightening Torque (a): 54 Nm (5.4 kg-m, 39.0 ft. lbs.).
NOTE: Do not rotate crankshaft while gaging plastic is installed.
5. Remove cap and using scale on gaging plastic envelope, measure gaging plastic width at its widest point. If clearance exceeds its limit, replace bearing. Always replace both upper and lower inserts as a unit.A new standard bearing may produce proper clearance. If not, it will be necessary to regrind crankshaft journal for use of 0.25 mm undersize bearing. After selecting new bearing, recheck clearance.
Bearing Clearance:
Standard: 0.020 - 0.040 mm (0.0008 - 0.0016 inch)
Limit: 0.060 mm (0.0023 inch)
SELECTION OF MAIN BEARINGS
Standard Bearing
If bearing is in malcondition, or bearing clearance is out of specification, select a new standard bearing according to following procedure and install it.
1. First check journal diameter by using following procedure. As shown in figure, crank webs of No.2 and No.3 cylinders have five stamped numerals. Three kinds of numerals ("1","2" and"3") represent following journal diameters.
Numeral Stamped: 1
Journal Diameter: 51.994- 52.000 mm (2.0470 - 2.0472 inch)
Numeral Stamped: 2
Journal Diameter: 51.988 - 51.994 mm (2.0468 - 2.0470 inch)
Numeral Stamped: 3
Journal Diameter: 51.982 - 51.988 mm (2.0465 - 2.0468 inch)
The first, second, third, fourth and fifth (left to right) stamped numerals represent journal diameters at bearing caps "1","2","3","4" and "5" respectively.
For example, in figure, the first (left most) numeral "3" indicates that journal diameter at bearing cap "1" is within 51.982 -51.988 mm, and second one "1" indicate that journal diameter at cap "2" is within 51.994 - 52.000 mm.
2. Next, check bearing cap bore diameter without bearing. On mating surface of cylinder block, four alphabets are stamped as shown in figure. Three kinds of alphabets ("A","B" and "C") represent following cap bore diameters.
Alphabet Stamped: A
Bearing Cap Bore Diameter (Without Bearing): 56.000 - 56.006 mm (2.2047 - 2.2050 inch)
Alphabet Stamped: B
Bearing Cap Bore Diameter (Without Bearing): 56.006 - 56.012 mm (2.2050 - 2.2052 inch)
Alphabet Stamped: C
Bearing Cap Bore Diameter (Without Bearing): 56.012 - 56.018 mm (2.2052 - 2.2054 inch)
The first, second, third, fourth, and fifth (left to right) stamped alphabets represent cap bore diameters of bearing caps "1","2","3","4", and "5", respectively. For example, in figure, the first (left most) alphabet "B" indicates that cap bore diameter of bearing cap "1" is within 56.006 - 56.012 mm, and the fifth (right most) alphabet "A" indicates that cap bore diameter of cap "5" is within 56.000 - 56.006 mm.
3. There are five kinds of standard bearings differing in thickness. To distinguish them, they are painted in following colors at the position as indicated in figure. Each color indicates following thickness at the center of bearing.
Color Painted: Green
Bearing Thickness: 1.996 - 2.000 mm (0.0786 - 0.0787 inch)
Color Painted: Black
Bearing Thickness: 1.999 - 2.003 mm (0.0787 - 0.0788 inch)
Color Painted: Colorless (no paint)
Bearing Thickness: 2.002 - 2.006 mm (0.0788 - 0.0789 inch)
Color Painted: Yellow
Bearing Thickness: 2.005 - 2.009 mm (0.0789 - 0.0790 inch)
Color Painted: Blue
Bearing Thickness: 2.008 - 2.012 mm (0.0790 - 0.0791 inch)
4. From numerals stamped on crank webs of No.2 and No.3 cylinders and the alphabets stamped on mating surface of cylinder block, determine new standard bearing to be installed to journal, by referring to table given below. For example, if numeral stamped on crank web is "1" and alphabet stamped on mating surface is "B",install a new standard bearing painted in "Black" to its journal.
Alphabet Stamped On Mating Surface (Bearing Cap Bore Diameter):
A:
1: Green
2: Black
3: Colorless
B:
1: Black
2: Colorless
3: Yellow
C:
1: Colorless
2: Yellow
3: Blue
New standard bearing to be installed.
5. Using gaging plastic, check bearing clearance with newly selected standard bearing. If clearance still exceeds its limit, use next thicker bearing and recheck clearance.
6. When replacing crankshaft or cylinder block due to any reason, select new standard bearings to be installed by referring to numerals stamped on new crankshaft or alphabets stamped on mating surface of new cylinder block.
^ Undersize Bearing (0.25 mm): 0.25 mm undersize bearing is available, in five kinds varying in thickness. To distinguish them, each bearing is painted in following colors at such position as indicated in figure. Each color represents following thicknesses at the center of bearing.
Color Painted: Green and Red
Bearing Thickness: 2.121 - 2.125 mm (0.0835 - 0.0836 inch)
Color Painted: Black and Red
Bearing Thickness: 2.124- 2.128 mm (0.0836 - 0.0837 inch)
Color Painted: Red only
Bearing Thickness: 2.127-2.131 mm (0.0837 - 0.0838 inch)
Color Painted: Yellow and Red
Bearing Thickness: 2.130 - 2.134 mm (0.0838 - 0.0839 inch)
Color Painted: Blue and Red
Bearing Thickness: 2.133 - 2.137 mm (0.0839 - 0.0840 inch)
^ If necessary, regrind crankshaft journal and select under size bearing to use with it as follows.
1. Regrind journal to following finished diameter.
Finished Diameter: 51.732 - 51.750 mm (2.0367 - 2.0373 inch)
2. Using micrometer, measure reground journal diameter. Measurement should be taken in two directions perpendicular to each other in order to check for out -of-round.
3. Using journal diameter measured above and alphabets stamped on mating surface of cylinder block, select an undersize bearing by referring to table given below. Check bearing clearance with newly selected undersize bearing.
Measured Journal Diameter: 51.744- 51.750 mm (2.0371 - 2.0373 inch)
Alphabets Stamped On Mating Surface Of Cylinder Block:
A (Green and Red)
B (Black and Red)
C (Red only)
Measured Journal Diameter: 51.738 - 51.744 mm (2.0369 - 2.0371 inch)
A (Black and Red)
B (Red only)
C (Yellow and Red)
Measured Journal Diameter: 51.732 - 51.738 mm (2.0367 - 2.0369 inch)
A (Red only )
B (Yellow and Red)
C (Blue and Red)
Undersize bearing to be installed.
REAR OIL SEAL
Carefully inspect oil seal for wear or damage. If its lip is worn or damaged, replace it.
For oil seal installation, press-fit rear oil seal so that oil seal housing end face is flush with oil seal end face.
FLYWHEEL
^ If ring gear is damaged, cracked or worn, replace flywheel.
^ If the surface contacting clutch disc is damaged, or excessively worn, replace flywheel.
^ Check flywheel for face runout with dial gauge. If runout exceeds its limit, replace flywheel.
Limit On Runout: 0.2 mm (0.0078 inch)
CYLINDER BLOCK
Distortion Of Gasketed Surface
Using straightedge and thickness gauge, check gasketed surface for distortion and, if flatness exceeds its limit, correct it.
Flatness:
Standard: 0.03 mm (0.0012 inch)
Limit: 0.06 mm (0.0024 inch)
HONING OR REBORING CYLINDERS
1. When any cylinder needs reboring, all other cylinders must also be rebored at the same time.
2. Select oversized piston according to amount of cylinder wear.
Oversize 0.25: 75.220 - 75.230 mm (2.9614- 2.9618 inch)
Oversize 0.50: 75.470 - 75.480 mm (2.9712-2.9716 inch)
3. Using micrometer, measure piston diameter.
4. Calculate cylinder bore diameter to be rebored.
D = A+B-C
D: Cylinder bore diameter to be rebored.
A: Piston diameter as measured.
B: Piston clearance = 0.02 - 0.04 mm (0.0008 - 0.0015 inch)
C: Allowance for honing = 0.02 mm (0.0008 inch)
5. Rebore and hone cylinder to calculated dimension.
NOTE: Before reboring, install all main bearing caps in place and tighten to specification to avoid distortion of bearing bores.
6. Measure piston clearance after honing.