Nissan X-Trail 32. Instruction — part 1091
CYLINDER BLOCK
EM-261
< UNIT DISASSEMBLY AND ASSEMBLY >
[QR25DE]
C
D
E
F
G
H
I
J
K
L
M
A
EM
N
P
O
• If it exceeds the limit, replace piston and piston pin assembly and/or cylinder block. Refer to
Re-boring Cylinder Bore
1.
Cylinder bore size is determined by adding piston to cylinder bore clearance to piston skirt diameter.
2.
Install lower cylinder block, and tighten mounting bolts to the specified torque. Otherwise, cylinder bores
may be distorted in final assembly. Refer to
EM-248, "Disassembly and Assembly"
for the tightening pro-
cedure.
3.
Cut cylinder bores.
NOTE:
• When any cylinder needs boring, all other cylinders must also be bored.
• Do not cut too much out of cylinder bore at a time. Cut only 0.05 mm (0.0020 in) or so in diameter at a
time.
4.
Hone cylinders to obtain the specified piston to cylinder bore clearance.
5.
Measure the finished cylinder bore for out-of-round and taper.
NOTE:
Measurement should be done after cylinder bore cools down.
CRANKSHAFT MAIN JOURNAL DIAMETER
• Measure the outer diameter of crankshaft main journals with a
micrometer (A).
• If out of the standard, measure the main bearing oil clearance.
Then use undersize bearing. Refer to
.
CRANKSHAFT PIN JOURNAL DIAMETER
• Measure the outer diameter of crankshaft pin journal with a micrometer.
• If out of the standard, measure the connecting rod bearing oil clearance. Then use undersize bearing. Refer
EM-284, "Connecting Rod Bearing"
.
OUT-OF-ROUND AND TAPER OF CRANKSHAFT
• Measure the dimensions at four different points as shown in the
figure on each main journal and pin journal with a micrometer.
• Out-of-round is indicated by the difference in dimensions between
and
at
and .
• Taper is indicated by the difference in dimension between
and
at
and
.
Re-bored size calculation: D = A + B - C
where,
A: Piston diameter as measured
B: Piston - to - cylinder bore clearance (standard value)
C: Honing allowance 0.02 mm (0.0008 in)
D: Bored diameter
Standard :
.
JPBIA0228ZZ
Standard
: Refer to
Limit:
Out-of-round [Difference
between
and
]
JPBIA0229ZZ
EM-262
< UNIT DISASSEMBLY AND ASSEMBLY >
[QR25DE]
CYLINDER BLOCK
• If the measured value exceeds the limit, correct or replace crankshaft.
• If corrected, measure the bearing oil clearance of the corrected main journal and/or pin journal. Then select
main bearing and/or connecting rod bearing. Refer to
EM-284, "Connecting Rod Bearing"
.
CRANKSHAFT RUNOUT
• Place a V-block (A) on a precise flat table to support the journals
on the both end of the crankshaft.
• Place a dial indicator (B) straight up on the No. 3 journal.
• While rotating crankshaft, read the movement of the pointer on the
dial indicator. (Total indicator reading)
• If it exceeds the limit, replace crankshaft.
CONNECTING ROD BEARING OIL CLEARANCE
Method by Calculation
• Install connecting rod bearings
to connecting rod
and cap,
and tighten connecting rod bolts to the specified torque. Refer to
EM-248, "Disassembly and Assembly"
for tightening procedure.
• Measure the inner diameter of connecting rod bearing with an inside micrometer.
(Bearing oil clearance) = (Connecting rod bearing inner diameter) – (Crankshaft pin journal diameter)
• If clearance exceeds the limit, select proper connecting rod bearing according to connecting rod big end
diameter and crankshaft pin journal diameter to obtain specified bearing oil clearance. Refer to
.
Method of Using Plastigage
• Remove engine oil and dust on crankshaft pin and the surfaces of each bearing completely.
• Cut a plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil
holes.
• Install connecting rod bearings to connecting rod and cap, and tighten connecting rod bolts to the specified
EM-248, "Disassembly and Assembly"
for the tightening procedure.
CAUTION:
Never rotate crankshaft.
Taper [Difference between
and
]
: Refer to
.
Standard and Limit
: Refer to
JSBIA2531ZZ
: Connecting rod bearing cap
: Example
: Inner diameter measuring direction
PBIC3275J
Standard and Limit
: Refer to
.
CYLINDER BLOCK
EM-263
< UNIT DISASSEMBLY AND ASSEMBLY >
[QR25DE]
C
D
E
F
G
H
I
J
K
L
M
A
EM
N
P
O
• Remove connecting rod cap and bearing, and using the scale (A)
on the plastigage bag, measure the plastigage (B) width.
NOTE:
The procedure when the measured value exceeds the limit is
same as that described in the “Method by Calculation”.
MAIN BEARING OIL CLEARANCE
Method by Calculation
• Install main bearings
to cylinder block
and lower cylinder
block
, and tighten lower cylinder block mounting bolts to the
specified torque. Refer to
EM-248, "Disassembly and Assembly"
for the tightening procedure.
• Measure the inner diameter of main bearing with a bore gauge.
(Bearing oil clearance) = (Main bearing inner diameter) – (Crank-
shaft main journal diameter)
• If clearance exceeds the limit, select proper main bearing according to main bearing inner diameter and
crankshaft main journal diameter to obtain specified bearing oil clearance. Refer to
.
Method of Using Plastigage
• Remove engine oil and dust on crankshaft main journal and the surfaces of each bearing completely.
• Cut a plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil
holes.
• Install main bearings to cylinder block and lower cylinder block, and tighten lower cylinder block mounting
bolts to the specified torque. Refer to
EM-248, "Disassembly and Assembly"
for the tightening procedure.
CAUTION:
Never rotate crankshaft.
• Remove main bearing cap and bearings, and using the scale (A)
on the plastigage bag, measure the plastigage (B) width.
NOTE:
The procedure when the measured value exceeds the limit is
same as that described in the “Method by Calculation”.
MAIN BEARING CRUSH HEIGHT
JSBIA2534ZZ
: Example
: Inner diameter measuring direction
PBIC3277J
Standard and Limit
: Refer to
.
JSBIA2534ZZ
EM-264
< UNIT DISASSEMBLY AND ASSEMBLY >
[QR25DE]
CYLINDER BLOCK
• When main bearing cap is removed after being tightened to the
specified torque with main bearings
installed, the tip end of bear-
ing must protrude
. Refer to
EM-248, "Disassembly and Assem-
• If the standard is not met, replace main bearings.
CONNECTING ROD BEARING CRUSH HEIGHT
• When connecting rod cap is removed after being tightened to the
specified torque with connecting rod bearings
installed, the tip
end of bearing must protrude
.
• If the standard is not met, replace connecting rod bearings.
LOWER CYLINDER BLOCK MOUNTING BOLT OUTER DIAMETER
• Perform only with M10 bolts.
• Measure the outer diameters (“d
1
”, “d
2”
) at two positions as shown
in the figure.
• If reduction appears in “A” range, regard it as “d
2
”.
• If it exceeds the limit (a large difference in dimensions), replace
lower cylinder block mounting bolt with a new one.
CONNECTING ROD BOLT OUTER DIAMETER
• Measure the outer diameter “d” at position as shown in the figure.
• If reduction appears in a position other than “d”, regard it as “d”.
• When “d ” exceeds the limit (when it becomes thinner), replace
connecting rod bolt with a new one.
: Example
Standard
: There must be crush height.
PBIC3279J
: Example
Standard
: There must be crush height.
PBIC3279J
Limit (“d
1
”–“d
2
”): 0.13 mm (0.0051 in)
PBIC0911E
Limit: 7.75 mm (0.3051 in)
PBIC0912E
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст