6A – 76 ENGINE MECHANICAL
7) Apply plastigage to the crankshaft journal unit as
shown in the illustration.
8) Install the main bearing caps. Apply engine oil to
the bolt threads and the seats. Tighten the bolts
to the specified torque.
Torque: 167 Nꞏm (17 kgꞏm/123 lb ft)
NOTE: Do not allow the crankshaft to rotate.
9) Remove the main bearing caps.
10) Measure the plastigage width and determine the
oil clearance. If the oil clearance exceeds the
specified limit, replace the main bearings as a
set and/or replace the crankshaft.
11) Clean the plastigage from the bearings and the
crankshaft.
Remove the crankshaft and the bearings.
Standard: 0.031 – 0.063 mm (0.0012 – 0.0025 in)
Limit: 0.11 mm (0.0043 in)3. Run-out
1) Carefully set the crankshaft on the V-blocks.
Slowly rotate the crankshaft and measure the
runout. If the crankshaft runout exceeds the
specified limit, the crankshaft must be replaced.
Standard: 0.05 mm (0.0020 in) or less
Limit: 0.08 mm (0.0031 in)
Measure the diameter and the uneven wear of
main journal and crank pin.
If the crankshaft wear exceeds the specified
limit, crankshaft must be replaced.
Main journal diameter
Standard: 69.917 – 69.932 mm (2.7526 – 2.7532 in)
Limit: 69.91 mm (2.7524 in)
Crank pin diameter
Standard: 52.915 – 52.930 mm (2.0833 – 2.0839 in)
Limit: 52.90 mm (2.0827 in)
Uneven wear limit
Standard: 0.05 mm (0.0020 in) or less
Limit: 0.08 mm (0.0031 in)
014RW055
014RW077
012RW068
6A – 80 ENGINE MECHANICAL
3. Piston and Connecting Rod Assembly
1) Apply engine oil to the cylinder bores, the
connecting rod bearings and the crankshaft pins
and each piston ring and piston.
2) Align the front mark (2) of piston and front mark
(3) of connecting rod then assemble them.
3) The N mark of the piston ring is faced toward the
top, check to see that the piston ring end gap is
correctly positioned.
Legend
(1) 1st piston ring end gap
(2) 2nd piston ring end gap
(3) Oil ring end gap4) Insert the piston/connecting rod assemblies into
each cylinder with the piston ring compressor.
The front marks must be facing the front of the
engine.
Piston Ring Compressor: 5-8840-9018-0
5) Match the numbered caps with the numbers on
the connecting rods. Align the punched marks
on the connecting rods and caps.
6) Apply engine oil to the threads and seating faces
of the nuts.
7) Tighten the cap nuts in 2 steps, using angular
tightening method as shown in the following
specifications.
1st step: 29 Nꞏm (3.0 kgꞏm/22 lb ft)
2nd step: 45°– 60°
After tightening the cap nuts, check to see that
the crankshaft rotates smoothly
4. Piston Cooling Oil Pipe
If the piston cooling oil pipe is forcibly assembled,
the end of the oil jet may bend. It could make it
impossible to supply oil to the piston cooling holes,
which will sometimes cause piston seizure.
Sufficient care should be taken to pipe assembly
work.
1) Tighten the bolt and oil jet plug to the specified
torque.
Torque:
M6: 8 Nꞏm (0.8 kgꞏm/6 lb ft)
M8: 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
Oiling Jet Plug: 30 Nꞏm (3.1 kgꞏm/22 lb ft)
5. Crank case
1) Refer to “Crank case” in this manual.
6. Apply liquid gasket (TB-1207C or equivalent) to
retainer then install it to rear end of cylinder block
within 5 minutes.
7. Crankshaft Rear Oil Seal
1) Tighten the adapter to the crankshaft rear and
section with 2 bolts.
2) Insert the oil seal into the peripheral section of
the adapter.
3) Insert the sleeve into the adapter and tighten it
with a bolt (M12 x 1.75L = 70) until the adapter
hits the sleeve.
4) Remove the adapter and the sleeve.
5) Check the dimension of the oil seal setting from
rear end of crankshaft.
Standard Dimension = 12.5 ± 0.3 mm
Oil Seal Installer: 5-8840-2359-0
2
3
1
015RW051
3
1
2
015RW083
ENGINE MECHANICAL 6A – 81
8. Cylinder Block Rear Plate (A/T)
Align the rear plate with the cylinder block dowel
pins.
Tighten the rear plate to the specified torque.
Torque: 97 Nꞏm (9.9 kgꞏm/72 lb ft)
9. Flywheel housing (M/T)
Align the flywheel housing with the cylinder block
dowel pins.
Tighten the bolt to the specified torque.
Torque: 97 Nꞏm (9.9 kgꞏm/72 lb ft)
10. Flywheel
1) Thoroughly clean and remove the oil from the
threads of crankshaft and flywheel fixing
surface.
2) Mount the flywheel on the crankshaft and then
install the washer.
3) Align the timing mark, cut out on the flywheel is
at lowest position for M/T model and
identification hole on the boss is highest position
for A/T model when cylinder No. 1 is at the TDC.
For M/T ModelFor A/T model
4) Tighten the flywheel bolts in 2 steps using
angular tightening method.
Torque: 1st step 60 Nꞏm (6.1 kgꞏm/44 lb ft)
Torque: 2nd step 60° – 90°
11. Timing Gear Case
1) Cut away the gasket protruding between the
cylinder block and the crank case fitting surfaces
(as shown in the illustration).
12.5 + 0.3–
012RW067
Timing mark
2
78
74
015RW121
Timing mark
7
4φ
304
015RW120
751
3
8
6 2 4
201RW021
6A – 82 ENGINE MECHANICAL
2) Apply liquid gasket (TB1207B or equivalent)
between the cylinder block and the crankcase
fitting surfaces.
3) Install the timing gear case to the cylinder body.
4) Tighten the timing gear case bolt together with
the timing gear case gasket to the specified
torque.
Torque: 20 Nꞏm (2.0 kgꞏm/14.5 lbꞏft)
12. Crankshaft Gear
1) Set key to crankshaft key groove.
2) The timing mark on the crankshaft gear must be
facing outward.
3) Use the crankshaft gear installer to install the
crankshaft gear.
Crankshaft installer: 9-8522-0021-0
Legend
(1) Crankshaft Gear Installer
(2) Crankshaft Gear13. Installation of the Timing Gear
1) Align teeth on the scissors gear and lock them
before install timing gear.
2) Align timing marks on each timing gear and
assemble them.
3) Refer to timing gear detail in this manual.
14. Timing Gear Case Cover
1) Remove lock bolt from idle gear A and remove
lock pin from idle gear C.
2) Install oil pump gear oil seal before assembling
timing gear case cover.
3) Clean fitting surface and apply liquid gasket
(TB1207C or equivalent) to fitting surface.
4) Tighten bolts to specified torque.
Torque: 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
12
2
012RW066
2
2~2.5mm
2~2.5mm
Apply liquid gasket around inside
of the bolt hole
Bolt hole
Inside
Outside
F06HX00001
012RW024
012RW064
6A – 92 ENGINE MECHANICAL
CYLINDER BLOCK
1
15
14
13
8
11
16
17
10
9
72
12
3
465
18
012RW023
Legend
(1) Cylinder Head
(2) Cylinder Head Gasket
(3) Flywheel
(4) Cylinder Block Rear Plate (A/T)
Flywheel Housing (M/T)
(5) Crankshaft Rear Oil Seal
(6) Retainer
(7) Timing Gear Case Cover
(8) Crankshaft Front Oil Seal(9) Timing Gear Case
(10) Gasket
(11) Balance Shaft
(12) Crank Case
(13) Piston Cooling Oil Pipe
(14) Main Bearing Cap
(15) Crankshaft
(16) Crankshaft Timing Gear
(17) Piston and Connecting Rod Assembly
(18) Cylinder Block
ENGINE MECHANICAL 6A – 93
DISASSEMBLY
1. Cylinder Head Assembly
Refer to “Cylinder Head” in this manual.
2. Cylinder Head Gasket.
3. Flywheel
4. Cylinder Block Rear Plate (A/T), or Flywheel
housing (M/T).
5. Crankshaft Rear Oil Seal.
Install the special tool as shown in the illustration
and remove the oil seal.
Oil Seal Remover: 5-8840-2360-0
6. Retainer
7. Timing Gear Case Cover
8. Crankshaft Front Oil Seal
1) Use a plastic hammer and a screwdriver to tap
around the oil seal to free it from the gear case
cover.
9. Timing Gears
Refer to “Timing Gear” in this manual.
10. Timing gear case
11. Gasket
12. Balance shaft right
13. Crank case assembly
14. Piston cooling oil pipe
15. Piston assembly
16. Main bearing cap
17. Crankshaft assembly
18. Cylinder block side cover right and left
19. Cylinder block
INSPECTION AND REPAIR
Make the necessary adjustments, repairs, and part
replacements if excessive wear or damage is
discovered during inspection.
1. Remove the cylinder head gasket and any other
material adhering to the upper surface of the
cylinder block.
Be very careful not to allow any material to
accidentally drop into the cylinder block.
Be very careful not to scratch the cylinder block.
2. Carefully remove liquid gasket, which was used
when assembled, from gear case, rear oil seal
retainer and crank case.
3. Wipe the cylinder block clean and visually check it.
4. Use a straight edge and a feeler gauge to measure
the four sides and the two diagonals of the cylinder
block upper face.
If the measured values exceed the limit, the cylinder
block must be replaced.
Limit: 0.20 mm (0.0079 in)
015RV002
012RW122
6A – 94 ENGINE MECHANICAL
Cylinder Bore Measurement
1. Use a cylinder gauge to measure the cylinder bore
measuring direction for thrust and radial at
measuring points.
Legend
Measuring Point 1; 20 mm
2; 90 mm
3; 160 mm
2. Select the right piston grade by the averaged
cylinder bore measurement (maximum and
minimum value eliminated).
Cylinder bore diameter mm(in)
Grade mark Standard
A 95.421 – 95.430 (3.7567 – 3.7571)
B 95.431 – 95.440 (3.7571 – 3.7575)
C 95.441 – 95.450 (3.7575 – 3.7579)
3. If measured values exceed the limit, replace or
adjust the cylinder block honing or boring.
Limit 95.950 mm (3.7776 in)
4. Boring of the cylinder bore is allowed until it is
0.5 mm (0.0197 in) diameter and oversized piston
is available as a service part.
Boring Cylinder Block
1. Use an oversized piston on the basis of above
mentioned cylinder using the largest inside
diameter.
2. Measure the piston outside diameter at right angles
with piston pin at a piston grade measuring point
69.75 mm (2.7461 in) from piston top surface and
calculate a inside diameter for cylinder boring.
3. Calculation of cylinder bore boring.
D + C – H (mm)
D; Outside diameter piston (mm)
C; Clearance between Cylinder bore and piston
0.092 – 0.110 mm (0.0036 – 0.0043 in)
H; Honing allowance
Less than 0.03 mm (0.0012 in)
The oversize pistons are available three grades.
4. Honing the cylinder bore after boring.
5. Measure cylinder bore after honing.
Difference between each cylinder bore
Less than 0.02 mm (0.0008 in)
Cylinder bore and piston grade (After boring) mm(in)
GradeOversize Piston Bore
Mark
Outside Diameter Diameter
A95.820 – 95.829 95.921 – 95.930
(3.7724 – 3.7728) (3.7764 – 3.7768)
B95.830 – 95.839 95.931 – 95.940
(3.7728 – 3.7732) (3.7768 – 3.7772)
C95.840 – 95.849 95.941 – 95.950
(3.7732 – 3.7736 ) (3.7772 – 3.7776)
REASSEMBLY
1. Cylinder Block
2. Piston Cooling Oil Pipe
1) Fix the cooling jet pipes with knock pins on the
cylinder block.
2) Install the oil pipe for piston cooling in the
cylinder block, tightening a relief valve (1) and
four joint bolts (2) to the specified torque.
If oil jet pipe is forcibly assembled, the end of oil
jet may bend. It could make it impossible to
supply oil to the piston cooling hole, sometimes
causing piston seizure.
Sufficient care should be taken to pipe assembly
work.
321
012RW117
6A – 96 ENGINE MECHANICAL
NOTE: Check to see that the crankshaft turns
smoothly by rotating it manually.
4. Piston Assembly
1) Refer to “Piston and connecting rod” in this
manual.
5. Cylinder Block Side Cover Right and Left
6. Balance Shaft Right.
7. Timing Gear Case
1) Cut out the liquid gasket forced out from
between the contact surface of cylinder block
and crankshaft.
2) Apply liquid gasket (TB1207B or equivalent) to
the fitting surface of the cylinder block and
crankcase.
3) Install timing gear case with gasket to cylinder
block and tighten to specified torque.
Torque: 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)8. Crankshaft Gear
Force key into crankshaft and force in crankshaft
gear along the key groove using a special tool (1)
with the crank gear (2) timing mark facing outside.
9. Install timing gear align the timing mark on each
timing gear.
For alignment of timing marks refer to “Timing
Gear” in this manual.
NOTE: Remove the locking bolt or pin from idle gear A
and idle gear C.
10. Assembling the gear case cover.
1) Install the oil seal on the oil pump assembly
before installing the gear case cover.
2) Apply liquid gasket to timing gear case.
NOTE: Be sure to apply liquid gasket evenly.
84159
610
237
012RW027
012RW064
12
2
012RW066
2
2~2.5mm
2~2.5mm
Apply liquid gasket around inside
of the bolt hole
Bolt hole
Inside
Outside
F06HX00001