ESP NISSAN PATROL 1998 Y61 / 5.G Engine Mechanical Workshop Manual

VALVE OIL SEAL
1. Remove timing belts.
2. Remove camshaft sprocket and back covers.
3. Remove camshaft brackets by loosening bracket nuts from
center to outside in two or three stages.
4. Remove camshaft oil seals and camshaft.
5. Remove valve lifters and mark order No. on each lifter.
6. Replace valve oil seal according to the following procedure.
When replacing valve oil seal, set the corresponding piston at
TDC. Failure to do so causes the valve to drop into the cylin-
der.
1) Set No. 1 cylinder at TDC.
2) Remove valve springs and valve oil seals for No. 1 and No. 6
cylinders. Valve spring seats should not be removed.
3) Install new valve oil seals for No. 1 and No. 6 cylinders as
illustrated. Reinstall valve springs. (narrow pitch side toward
cylinder head)
4) Install valve spring retainers on intake valves and valve rotators
on exhaust valves, and remount valve assembly.
5) Set No. 2 cylinder at TDC.
6) Replace valve oil seals for No. 2 and No. 5 cylinders according
to steps 2) and 3).
7) Set No. 3 cylinder at TDC.
8) Replace valve oil seals for No. 3 and No. 4 cylinders according
to steps 2) and 3).
9) Install valve lifters in original positions.
SEM716B
SEM790F
SEM745B
SEM746B
OIL SEAL REPLACEMENT
EM-21

4. Measure outer diameter ``Dm'' of each crankshaft main journal.
5. Calculate main bearing clearance.
Main bearing clearance = A þ Dm:
Standard 0.036 - 0.063 mm (0.0014 - 0.0025 in)
Limit 0.12 mm (0.0047 in)
If it exceeds the limit, replace bearing.
+If clearance cannot be adjusted within the standard of any
bearing, grind crankshaft journal and use undersized bearing.
+If crankshaft or cylinder block is replaced, select thickness of
main bearings as follows:
a. Grade number of each cylinder block main journal is punched
on the respective cylinder block. These numbers are punched
in either Arabic or Roman numerals.
b. Grade number of each crankshaft main journal is punched on
the respective crankshaft. These numbers are punched in
either Arabic or Roman numerals.
c. Select main bearing with suitable thickness according to the
following table.
Main bearing grade number:
Main journal grade number 0 1 2
Crankshaft
journal grade
number0012
1123
2234
For example:
Main journal grade number: 1
Crankshaft journal grade number: 2
Main bearing grade number=1+2=3
Connecting rod bearing (Big end)
1. Install connecting rod bearing to connecting rod and cap.
2. Install connecting rod cap to connecting rod.
Tighten bolts to the speci®ed torque. Refer to EM-20.
3. Measure inner diameter ``C'' of each bearing.
AEM033
SEM912A
SEM911A
AEM027
CYLINDER BLOCK
Inspection (Cont'd)
EM-52

Assembly
PISTON
1. Install new snap ring on one side of piston pin hole.
2. Heat piston to 60 to 70ÉC (140 to 158ÉF) and assemble piston,
piston pin, connecting rod and new snap ring.
+Align the direction of piston and connecting rod.
+Numbers stamped on connecting rod and cap correspond
to each cylinder.
+After assembly, make sure connecting rod swings
smoothly.
3. Set piston rings as shown.
CAUTION:
+When piston rings are not replaced, make sure that piston
rings are mounted in their original positions.
+Install new piston rings either side up if there is no punch-
mark.
+Align piston rings so that end gaps are positioned as
shown.
CRANKSHAFT
1. Set main bearings in their proper positions on cylinder block
and main bearing cap.
+Con®rm that correct main bearings are selected by using
Method A or Method B. Refer to EM-52.
+Apply new engine oil to bearing surfaces.
SEM146B
SEM754B
SEM156B
SEM160B
SEM157B
CYLINDER BLOCK
EM-54

2. Install crankshaft and main bearing caps and tighten bolts to
the speci®ed torque.
+Apply new engine oil to the bolt thread and seat surface.
+Prior to tightening bearing cap bolts, shift crankshaft back
and forth to properly seat the bearing cap.
+Tighten bearing cap bolts gradually in two or three steps.
Start with center bearing and move outward as shown in
®gure.
+After securing bearing cap bolts, make sure crankshaft
turns smoothly by hand.
3. Measure crankshaft end play.
Crankshaft end play:
Standard
0.050 - 0.18 mm (0.0020 - 0.0071 in)
Limit
0.30 mm (0.0118 in)
If beyond the limit, replace thrust bearing with a new one.
4. Install connecting rod bearings in connecting rods and connect-
ing rod caps.
+Con®rm that correct bearings are selected. Refer to ``Con-
necting rod bearing (Big end)'', EM-52.
+Install bearings so that oil hole in connecting rod aligns
with oil hole of bearing.
+Apply new engine oil to bearing surfaces, bolt threads and
seating surfaces.
5. Install pistons with connecting rods.
a. Install them into corresponding cylinders with Tool.
+Make sure connecting rod does not scratch cylinder wall.
+Make sure connecting rod bolts do not scratch crankshaft
pin journals.
+Arrange so that front mark on piston head faces toward
front of engine.
+Apply new engine oil to piston rings and sliding surface of
piston.
b. Install connecting rod caps.
+Apply new engine oil to bolt threads and nut seating sur-
faces.
Tighten connecting rod cap nuts using the following procedure.
(1) Tighten to 14 to 16 Nzm
(1.4 to 1.6 kg-m, 10 to 12 ft-lb).
(2) Turn nuts 60 to 65É clockwise with an angle wrench. If
an angle wrench is not available, tighten nuts to 37 to
45 Nzm (3.8 to 4.6 kg-m, 27 to 33 ft-lb).
SEM801FA
SEM756B
SEM757B
SEM936A
SEM759B
CYLINDER BLOCK
Assembly (Cont'd)
EM-55