
Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-40
Valves and Valve Guides InspectionS7RS0B1406026
Valve Guide
Valve stem-to-guide clearance
Using a micrometer and bore gauge, take diameter readings on valve stems and guides to check stem-to-guide
clearance.
Be sure to take reading at more than one place along the length of each stem and guide.
If clearance exceeds limit, replace valve and valve guide.
Valve stem and valve guide specification
Valve stem end deflection
If bore gauge is not available, check end deflection of
valve stem with a dial gauge instead.
Move stem end in directions (1) and (2) to measure end
deflection.
If deflection exceeds its limit, replace valve stem and
valve guide.
Valve stem end deflection limit
In: 0.14 mm (0.005 in.)
Ex: 0.18 mm (0.007 in.) Va l v e
Visual inspection
• Remove all carbon from valves.
• Inspect each valve for wear, burn or distortion at its
face and stem end, as necessary, replace it.
• Inspect valve stem end face for pitting and wear. If pitting or wear is found there, valve stem end may be
resurfaced, but not too much to grind off its chamber.
When it is worn out too much that its chamber is gone,
replace valve.
Item Standard Limit
Valve stem diameter [A] In 5.465 – 5.480 mm (0.2150 – 0.2157 in.) —
Ex 5.440 – 5.455 mm (0.2142 – 0.2148 in.) —
Valve guide bore [B] In & Ex 5.500 – 5.512 mm (0.2165 – 0.2170 in.) —
Stem-to-guide clearance In 0.020 – 0.047 mm (0.0008 – 0.
0018 in.) 0.070 mm (0.0028 in.)
Ex 0.045 – 0.072 mm (0.0017 – 0. 0028 in.) 0.090 mm (0.0035 in.)
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Downloaded from www.Manualslib.com manuals search engine 1D-43 Engine Mechanical:
Valve Spring InspectionS7RS0B1406028
Valve Spring Free Length and Preload
Referring to data, check to be sure that each spring is in
sound condition, free of any evidence of breakage or
weakening. Remember, weakened valve springs can
cause chatter, not to mention possibility of reducing
power output due to gas leakage caused by decreased
seating pressure.
Valve spring free length
Standard: 39.37 mm (1.550 in.)
Limit: 36.49 mm (1.437 in.)
Valve spring preload
Standard: 161– 185 N (16.1 – 18.5 kg)
(35.4 – 40.7 lb / 1.240 in.)
Limit: 159 N (15.9 kg) for 31.50 mm (35.1 lb / 1.240 in.) Spring Squareness
Use a square and surface plate to check each spring for
squareness in terms of clearance between end of valve
spring and square. Valve springs found to exhibit a
larger clearance than limit must be replaced.
Valve spring squareness
Limit: 1.7 mm (0.067 in.)
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Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-48
Piston clearance
Measure cylinder bore diameter and piston diameter to
find their difference which is piston clearance. Piston
clearance should be within spec ification as follows. If it is
out of specification, rebore cylinder and use oversize
piston.
NOTE
Cylinder bore diameters used here are
measured in thrust direction at two positions.
Piston clearance
Standard (used piston): 0.032 – 0.061 mm (0.0013 –
0.0024 in.)
Standard (new piston with coating): 0.010 – 0.051
mm (0.0004 – 0.0020 in.)
Limit: 0.161 mm (0.0063 in.)
Ring groove clearance
Before checking, piston grooves must be clean, dry and
free of carbon deposits.
Fit new piston ring (1) into piston groove, and measure
clearance between ring and ring land by using thickness
gauge (2). If clearance is ou t of specification, replace
piston.
Ring groove clearance
Piston Ring
Piston ring end gap
To measure end gap, insert piston ring (2) into cylinder
bore and then measure the gap by using thickness
gauge (1).
If measured gap exceeds limit, replace ring.
NOTE
Decarbonize and clean top of cylinder bore
before inserting piston ring.
Ring groove clearance
“a”: 7.0 mm (0.28 in.)
Standard Limit
Top ring 0.04 – 0.08 mm
(0.0016 – 0.0031 in.) 0.12 mm (0.0047 in.)
2nd ring 0.03 – 0.07 mm
(0.0012 – 0.0027 in.) 0.10 mm (0.0394 in.)
Oil ring 0.04 – 0.12 mm
(0.0016 – 0.0047 in.) —
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Item Standard
Limit
To p r i n g 0.20 – 0.33 mm
(0.0079 – 0.0129 in.) 0.7 mm (0.0276 in.)
2nd ring 0.43 – 0.56 mm
(0.0170 – 0.0220 in.) 1.0 mm (0.0394 in.)
Oil ring 0.10 – 0.40 mm
(0.0040 – 0.0157 in.) 0.7 mm (0.0276 in.)
“a”: 120 mm (4.72 in.)
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Downloaded from www.Manualslib.com manuals search engine 1D-49 Engine Mechanical:
Piston Pins and Connecting Rods InspectionS7RS0B1406033
Piston Pin
Visual inspection
Check piston pin, connecting rod small end bore and
piston bore for wear or damage, paying particular
attention to condition of small end bore bush. If pin,
connecting rod small end bore or piston bore is badly
worn or damaged, replace pin, connecting rod and/or
piston.
Piston pin clearance
Check piston pin clearance in small end and piston.
Replace connecting rod and/or piston if its small end is
badly worn or damaged or if measured clearance
exceeds limit.
Piston pin clearance in connecting rod small end
Standard: 0.003 – 0.014 mm (0.0001 – 0.0006 in.)
Piston pin clearance in piston
Standard: 0.006 – 0.017 mm (0.00024 – 0.00067 in.)
Small-end bore
20.003 – 20.011 mm (0.7875 – 0.7878 in.)
Piston pin dia.
19.997 – 20.000 mm (0.7873 – 0.7874 in.)
Piston bore
20.006 – 20.014 mm (0.7876 – 0.7880 in.)Connecting Rod
Big-end side clearance
Check big-end of connecting rod for side clearance, with
rod fitted and connected to its crank pin in the normal
manner. If measured clearance is found to exceed its
limit, replace connecting rod.
Big-end side clearance
Standard: 0.25 – 0.40 mm (0.0098 – 0.0157 in.)
Limit: 0.55 mm (0.0217 in.)
Connecting rod alignment
Mount connecting rod on aligner to check it for bow and
twist. If measured value exceeds the limit, replace it.
Connecting rod alignment
Limit on bow: 0.05 mm (0.0020 in.)
Limit on twist: 0.10 mm (0.0039 in.)
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Downloaded from www.Manualslib.com manuals search engine 1D-51 Engine Mechanical:
Connecting Rod Bearing Clearance1) Before checking bearing clearance, clean bearing and crank pin.
2) Install bearing in connecting rod and bearing cap.
3) Place a piece of gauging plastic (1) to full width of crank pin as contacted by bearing (parallel to
crankshaft), avoiding oil hole.
4) Install rod bearing cap (1) to connecting rod. When installing cap, be sure to point arrow mark (2)
on cap to crankshaft pulley side, as shown in figure.
After applying engine oil to bearing cap bolts (3),
tighten bearing cap bolts (3) gradually as follows.
a) Tighten all bearing cap bolts to 15 N ⋅m (1.5 kgf-
m, 11.0 lb-ft)
b) Retighten them to 45°
c) Repeat Step b) once again.
Tightening torque
Connecting rod bearing cap bolt: 15 N ⋅m (1.5
kgf-m, 11.0 lb-ft) and then retighten by
turning through 45 ° twice 5) Remove cap and using a scale (1) on gauging
plastic envelope (2), measure gauging plastic (2)
width at the widest point (clearance).
If clearance exceed its limit, use a new standard size
bearing referring to “Selection of Connecting Rod
Bearings: ”.
After selecting new bearing, recheck clearance.
Connecting rod bearing clearance
Standard: 0.029 – 0.047 mm (0.0011 – 0.0018 in.)
Limit: 0.065 mm (0.0026 in.)
6) If clearance can not be brought to its limit even by using a new standard size bearing, use next thicker
bearing and recheck clearance or regrind crank pin
to undersize and use 0.25 mm undersize bearing.
Selection of Connecting Rod Bearings
NOTE
• If bearing is in malcondition, or bearing clearance is out of specification, select a
new standard bearing according to the
following procedure and install it.
• When replacing crankshaft or connecting rod and its bearing due to any reason,
select new standard bearings to be
installed by referring to numbers stamped
on connecting rod and its cap and/or
alphabets stamped on crank web of No.3
cylinder.
1) Check stamped numbers on connecting rod and its cap as shown.
Three kinds of numbers (“1”, “2” and “3”) represent
the following connecting rod big end inside
diameters.
For example, stamped number “1” indicates that
corresponding connecting rod big end inside
diameter is 45.000 – 45.006 mm (1.7717 – 1.7718
in.).
Connecting rod big end inside diameter
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Stamped
numbers Connecting rod big end inside diameter
1 45.0000 – 45.0060 mm (1.7717 – 1.7718 in.)
2 45.0061 – 45.0120 mm (1.7719 – 1.7721 in.)
3 45.0121 – 45.0180 mm (1.7722 – 1.7723 in.)
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Downloaded from www.Manualslib.com manuals search engine 1D-59 Engine Mechanical:
Main Bearings InspectionS7RS0B1406038
General Information
• Service main bearings are available in standard size and 0.25 mm (0.0098 in.) undersize, and each of them
has 5 kinds of bearings differing in tolerance.
• Upper half of bearing (1) has oil groove (2) as shown in figure.
Install this half with o il groove to cylinder block.
• Lower half of bearing does not have an oil groove.
Visual Inspection
Check bearings for pitting, scratches, wear or damage.
If any malcondition is foun d, replace both upper and
lower halves. Never replace either half without replacing
the other half.
Main Bearing Clearance
NOTE
Do not rotate crankshaft while gauging
plastic is installed.
Check clearance by using ga uging plastic according to
the following procedure.
1) Remove bearing caps.
2) Clean bearings and main journals.
3) Place a piece of gauging plastic (1) the full width of bearing (parallel to crankshaft) on journal, avoiding
oil hole. 4) Tighten main bearing cap No.1 bolts (a) and main
bearing cap No.2 bolts (b) gradually as follows.
a) Tighten bolts (“1” through “10”) to 30 N ⋅m (3.0
kgf-m, 22.0 lb-ft) according to numerical order in
the figure.
b) In the same manner as in Step a), tighten them to 50 N ⋅m (5.0 kgf-m, 36.5 lb-ft).
c) In the same manner as in Step a), retighten them to 60 °.
d) Tighten bolts (“11” through “18”) to 25 N ⋅m (2.5
kgf-m, 18.0 lb-ft) according to numerical order in
the figure.
Tightening torque
Main bearing cap No.1 bolt (a): 30 Nm (3.0
kgf-m, 22.0 lb-ft), 50 Nm (5.0 kgf-m, 36.5 lb-ft)
and then retighten by turning through 60°
Main bearing cap No.2 bolt (b): 25 N·m (2.5
kgf-m, 18.0 lb-ft)
5) Remove bearing caps and using scale (1) on gauging plastic envelop (2), measure gauging 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.
Main bearing clearance
Standard: 0.021 – 0.041 mm (0.0008 – 0.0016 in.)
Limit: 0.054 mm (0.0021 in.)
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Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-60
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 the following procedure and install it.
1) First check journal diameter. As shown in the figure, crank web No.2 has stamped numbers.
Three kinds of numbers (“1”, “2” and “3”) represent
the following journal diameters.
Stamped numbers on crank web No.2 represent
journal diameters marked with an arrow in the figure
respectively. For example, stamped number “1”
indicates that corresponding journal diameter is
51.9940 – 52.0000 mm (2.0471 – 2.0472 in.).
Crankshaft journal diameter2) Next, check bearing cap bore diameter without bearing. On mating surface of cylinder block, five
alphabets are stamped as shown in figure.
Three kinds of alphabets (“A”, “B” and “C”) or
numbers (“1”, “2” and “3”) represent the following
cap bore diameters.
Stamped alphabets or numbers on cylinder block
represent bearing cap bore diameter marked with an
arrow in the figure respectively.
For example, stamped “A” or “1” indicates that
corresponding bearing cap bo re diameter is 56.0000
– 56.0060 mm (2.2048 – 2.2049 in.).
Crankshaft bearing cap bore
Stamped
numbers Journal diameter
1 51.9940 – 52.0000 mm
(2.0471 – 2.0472 in.)
2 51.9880 – 51.9939 mm
(2.0468 – 2.0470 in.)
3 51.9820 – 51.9879 mm
(2.0465 – 2.0467 in.)
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Stamped alphabet
(number) Bearing cap bore diameter (without
bearing)
A or 1 56.0000 – 56.0060 mm
(2.2048 – 2.2049 in.)
B or 2 56.0061 – 56.0120 mm
(2.2050 – 2.2051 in.)
C or 3 56.0121 – 56.0180 mm
(2.2052 – 2.2054 in.)
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Downloaded from www.Manualslib.com manuals search engine 1D-61 Engine Mechanical:
3) There are 5 kinds of standard bearings differing in thickness. To distinguish them, they are painted in the following colors at the position as indicated in figure.
Each color indicated the following th ickness at the center of bearing.
Standard size of crankshaft main bearing thickness
4) From number stamped on crank web No.2 and alphabets stamped on cylinder block, determine new standard bearing to be installed to journal, by referring to the table shown.
For example, if number stamped on crank web No.2 is “1 ” and alphabet stamped on cylinder block is “B”, install a
new standard bearing painted in “Brown” to its journal.
New standard size crankshaft main bearing specification
5) Using scale (1) on gauging plastic (2), check be aring clearance with newly selected standard bearing.
If clearance still exceeds its limit, use ne xt 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 number stamped on new crankshaft or alphabets stamped on new cylinder block.
Color
painted Bearing thickness
Purple 1.992 – 1.996 mm (0.07843 – 0.07858 in.)
Brown 1.995 – 1.999 mm (0.07855 – 0.07870 in.) Green 1.998 – 2.002 mm (0.07867 – 0.07882 in.)Black 2.001 – 2.005 mm (0.07878 – 0.07893 in.)
Colorless (no paint) 2.004 – 2.008 mm (0.07890 – 0.07906 in.)
1. Paint
Number stamped on crank web No.2 (Journal diameter)
123
Alphabet stamped on cylinder block (Cap bore dia.) A or 1 Purple Brown Green
B or 2 Brown Green Black
C or 3 Green Black Colorless
New standard bearing to be installed
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