1998 NISSAN PATROL engine

CAUTION:
+When installing sliding parts such as bearings and
pistons, apply engine oil to the sliding surfaces.
+Place removed parts, such as bearings and bearing caps,
in their proper order and direction.
+When installing connecting rod bolts and main bearing cap
bolts, apply new engine oil to threads and seating surfaces
of nuts.
+Do not allow any magnetic materials to contact the ring
gear teeth of drive plate.
Disassembly
PISTON AND CRANKSHAFT
1. Place engine on a work stand.
2. Remove timing belt and injection pump.
3. Drain coolant and remove water pump.
4. Remove front cover.
5. Drain oil.
6. Remove oil pan and oil pump.
7. Remove cylinder head.
8. Remove pistons with connecting rod.
+To disassemble piston and connecting rod, remove snap ring
®rst. Then heat piston to 60 to 70ÉC (140 to 158ÉF) and use
piston pin press to remove pin.
+When piston rings are not replaced, make sure that piston
rings are mounted in their original positions.
+When replacing piston rings, if there is no punchmark,
install with either side up.
9. Remove bearing cap bolts and main bearing caps in the order
shown, then remove crankshaft.
+Loosen bolts in two or three steps.
Inspection
PISTON AND PISTON PIN CLEARANCE
1. Measure inner diameter of piston pin hole ``dp''.
Standard diameter ``dp'':
26.995 - 27.005 mm (1.0628 - 1.0632 in)
SEM750B
SEM877B
SEM801F
SEM672E
CYLINDER BLOCK
EM-47

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