1999 LAND ROVER DEFENDER tow

ENGINE
37
DESCRIPTION AND OPERATION An additional tapping is included at the front left hand side of the cylinder head to supply oil to the chain lubrication
jet and a through hole near the front centre of the cylinder head allows a passage of oil through from the cast-in
groove to lubricate the timing chain and camshaft sprocket.
At the centre front of the cylinder head, the cast-in groove channels oil into the rocker shaft via the front rocker
shaft fixing. Oil flow through the rocker shaft and clearance around the rocker shaft fixings provides oil feed to the
camshaft bearings.
A tapping towards the right hand side of the cylinder head diverts oil supply from the cast-in groove down to a stub
pipe which attaches to a feed line to the vacuum pump. An hydraulic tensioner is located below the vacuum stub
pipe which receives oil through a small hole in the side of the tensioner body to force a plunger against a plastic
faced adjuster shoe for timing chain tensioning. Oil from the vacuum pump is returned to the a port in the timing
chain cover via a short hose which connects to stub pipes at both ends using spring clips.
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12ENGINE
14
OVERHAUL Valve springs - Inspection
1.Check free length of valve springs:
Free length =47.0±0.25 mm (1.85±0.011 in)
CAUTION: Valve springs must be replaced
as a set, if springs are to be refitted, keep
them in their fitted order.
Valves and valve guides - Inspection
1.Clean carbon from valves, check valves for
burning, pitting or cracking; replace as
necessary.
2.Clean carbon from valve seat inserts, remove all
loose particles on completion.
3.Check valve seat inserts for pitting and burning.
CAUTION: It is not permissible to recut or
replace valve seat inserts.
4.Remove carbon deposits from valve guides
using toolLRT-12-186.
CAUTION: Tool must be inserted from
combustion chamber face side of cylinder
head, ensure all loose particles of carbon
are removed on completion.
5.Check and record diameter of each valve stem.
Valve stem diameter:
Inlet = 6.907 to 6.923 mm (0.2719 to 0.2725 in)
Exhaust = 6.897 to 6.913 mm (0.2715 to 0.2721
in)
6.Renew any valve if stem diameter is less than
specified.7.Check and record valve stem to guide clearance
using the following procedures:
8.Insert each valve into its respective guide.
9.Extend valve head 10 mm (0.375 in) out of valve
seat and position a DTI gauge to rear of valve
head.
10.Move valve towards front of cylinder head and
zero DTI gauge ensuring that stylus of gauge
remains in contact with valve head.
11.Move valve towards rear of cylinder head, record
gauge reading to give valve stem to guide
clearance.
Valve stem to guide clearance:
Inlet valve = 0.025 to 0.059 mm (0.0009 to
0.0023 in)
Exhaust valve = 0.035 to 0.069 mm (0.0013 to
0.0027 in)
CAUTION: If stem to guide clearance
exceeds figures given and valve stem
diameters were as specified, cylinder head
assembly must be replaced; it is not possible to
replace valve guides.
12.Repeat above procedures for remaining valves.
CAUTION: Keep valves in their fitted order.
13.Check face angle of each valve, renew any
valve with incorrect face angles, do not attempt
to recut.
Valve face angle:
Inlet =29°48’±12’
Exhaust =44°48’±12’
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ENGINE
29
OVERHAUL 10.Remove crankshaft pulley bolt.
11.Fit Woodruff key to crankshaft.
12.Fit oil pump drive chain to rear row of teeth on
crankshaft sprocket i.e. teeth furthest away from
timing mark on sprocket.
13.Fit sprocket to crankshaft ensuring that timing
mark on sprocket is facing towards front end of
crankshaft.
14.Fit oil pump drive sprocket to oil pump and drive
chain ensuring that’D’shape on sprocket is
located on flat on oil pump drive shaft.
15.Apply Loctite 242 to threads of oil pump drive
sprocket bolt, fit bolt and tighten to25 Nm (18
lbf.ft).
16.Fit timing chain fixed guide, fit bolts and tighten
to:
M6 bolt -10 Nm (7 lbf.ft)
M10 bolt -45 Nm (34 lbf.ft)
17.Fit timing chain adjustable guide, fit bolt and
tighten to25 Nm (18 lbf.ft).
18.Fit camshaft sprocket to timing chain with timing
mark on sprocket between the 2 coloured links,
suitably retain sprocket to chain.
19.Fit timing chain to crankshaft sprocket aligning
coloured link to timing mark on sprocket.
CAUTION: Ensure timing marks are
positioned as shown - No. 1 piston at TDC
firing.
20.Apply an even film film of sealant, Part No. STC
4600 to mating face of timing cover and spread
to an even film using a roller.
CAUTION: Assembly and bolt tightening
must be completed within 20 minutes of
applying sealant.
21.Fit timing cover, fit bolts in their original fitted
positions and working from the centre outwards,
tighten progressively to27 Nm (20 lbf.ft).
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12ENGINE
34
OVERHAUL
5.Starting with No. 1 piston, invert piston and with
arrow on piston crown pointing towards REAR of
cylinder block, insert piston into No. 1 cylinder
bore.
6.Position piston with bottom of skirt 25 mm (1.0
in) from top of cylinder bore.
7.Using feeler gauges, measure and record
clearance between piston skirt and LEFT HAND
side of cylinder bore 60 mm (2.4 in) from top of
bore:
Piston to cylinder bore clearance =0.171 to
0.207 mm (0.007 to 0.008 in)
8.Repeat above procedures for remaining pistons.
CAUTION: Oversize pistons are not
available, if piston to cylinder bore
clearance exceeds limits given, repeat
check using a new piston; if clearances are still
excessive, replace cylinder block.
Piston and 1st compression rings fitted to Engine
Serial No. Prefixes 15P to 19P may be fitted to
Engine Serial No. Prefixes 10P to 14P in engine
sets only. Oil control and 2nd compression rings
are interchangeable between all engines.
9.Check fit of each gudgeon pin in its piston. Pin
must be a tight, sliding fit with no perceptible
side play.
10.Measure gudgeon pin diameter at each end and
centre of pin. Renew gudgeon pin and piston as
an assembly if diameters are less than specified
or if excessive pin to piston side play is evident.
Gudgeon pin diameter =29.995 to 30.000 mm
(1.180 to 1.181 in)
11.Check connecting rod small-end bushes for
wear, check that gudgeon pin is a sliding fit in
the bush with no perceptible side play.
CAUTION: Small-end bushes cannot be
replaced, a new connecting rod must be
fitted.
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ENGINE
35
OVERHAUL Piston ring gaps - Checking
1.Insert new compression and oil control piston
rings in turn into No. 1 cylinder bore 30 mm (1.25
in) from top of bore and check ring fitted gaps;
ensure rings are kept square to bore when
checking gaps.
1st compression ring fitted gap =0.30 to 0.40
mm (0.012 to 0.016 in)
2nd compression ring fitted gap =0.40 to 0.60
mm (0.016 to 0.024 in)
Oil control ring fitted gap =0.25 to 0.50 mm
(0.01 to 0.02 in)
Repeat for each cylinder bore in turn.
CAUTION: Ensure rings are suitably
identified with the cylinder bore in which
they were checked and are fitted to the
piston for that bore.
2.Fit oil control expander and ring to piston.
3.Fit 2nd compression ring with’TOP’marking
upwards.
4.Fit 1st compression ring with’TOP’marking
upwards.
5.Check piston ring to groove clearance:
1st compression ring -Not measured
2nd compression ring =0.050 to 0.082 mm
(0.02 to 0.003 in)
Oil control ring =0.050 to 0.082 mm (0.02 to
0.003 in)
Pistons and connecting rods - Assembling
1.Lubricate gudgeon pin, gudgeon pin holes in
piston and small-end bush with engine oil.
2.Position piston to its respective connecting rod
with arrow on piston crown on the same side as
the cast boss on the connecting rod.
3.Fit gudgeon pin to its respective piston and
connecting rod; secure with new circlips.
CAUTION: Ensure circlips are fully seated
in their grooves.
4.Repeat above procedures for remaining pistons.
5.Lubricate piston rings and cylinder bores with
engine oil.
6.Check that rings are free to rotate, position ring
gaps at 120°to each other and away from the
thrust - LH side of piston - viewed from front of
piston.
7.Using a suitable piston ring clamp, compress
piston rings.
8.Insert connecting rod and piston into its
respective cylinder bore, ensuring that the arrow
on piston crown and the cast boss on connecting
rod are facing towards the front of the cylinder
block.
CAUTION: Ensure that connecting rod
does not contact cylinder bore or oil squirt
jet. Do not pull connecting rod fully down
cylinder bore at this stage.
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19FUEL SYSTEM
12
REPAIR FUEL TANK
Service repair no - 19.55.01
Remove
1.Drain fuel tank.See Adjustment.
2.Raise rear of vehicle.
WARNING: Support on safety stands.
Vehicles fitted with tow bar
3.Remove 2 bolts securing support bars to drop
plate.
4.Loosen 2 nuts securing support bars to chassis.All Vehicles
5.Remove 2 nuts securing fuel tank support to rear
chassis member.
6.Remove 2 bolts securing fuel tank support plate
to chassis member.
7.Release clip securing filler hose and release
hose from filler neck.
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19FUEL SYSTEM
14
REPAIR Refit
19.Clean fuel pump and mating face.
20.Fit new fuel pump sealing ring.
21.Fit fuel pump and secure with locking ring.
22.Fit breather hose and secure clip.
23.Position heat shield and secure with scrivits.
24.With assistance position fuel tank and support
plate.
25.Connect fuel hoses and multiplug to fuel pump.
26.Connect filler neck breather and secure clip.
27.Position vent hose and secure to chassis clips.
28.Raise fuel tank to its fitted position.
29.Fit nuts and bolts securing fuel tank and tighten
to25 Nm (18 lbf.ft).
30.Connect filler hose and secure clip.
Vehicles fitted with tow bar
31.Position support bar and tighten nuts and bolts.
32.Reconnect battery negative lead.
33.Fit battery cover.NECK - FUEL TANK FILLER
Service repair no - 19.55.07
Remove
1.Drain fuel tank.See Adjustment.
2.Loosen clip securing breather hose to fuel filler
neck and release hose.
3.Loosen clip securing fuel filler hose to neck and
release hose.
4.Remove screw and release earth lead from filler
neck.
5.Remove grommet securing filler neck to body.
6.Remove filler neck from body.
Refit
7.Fit filler neck to body.
8.Coat rubber grommet with soap solution.
9.Fit rubber grommet securing filler neck to body.
10.Connect earth lead and tighten screw.
11.Connect filler hose to neck and tighten clip.
12.Fit breather hose to filler neck and secure with
clip.
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MANIFOLD AND EXHAUST SYSTEM
3
DESCRIPTION AND OPERATION Front pipe assembly
The front pipe is of welded and fabricated tubular construction. The front pipe is connected to a flange on the
turbocharger and secured with three flanged nuts and sealed with a metal laminated gasket. The front pipe
incorporates a flexible pipe near the connection with the turbocharger and terminates in a flanged connection with
the intermediate pipe.
The flexible pipe is formed into a concertina shape with woven metal strands around its outer diameter. The
flexible pipe allows for ease of exhaust system alignment and also absorbs engine vibration. The woven metal
strands also increase the longevity of the flexible pipe.
The front pipe is attached via a bracket and a mounting rubber to the chassis. The mounting rubber allows ease of
alignment and vibration absorption.
Intermediate pipe and silencer
The intermediate pipe is of welded and fabricated tubular construction. It connects at its forward end to the front
pipe flange. Two captive studs on the intermediate pipe flange allow for attachment to the front pipe with locknuts.
The rear section of intermediate pipe connects to the tail pipe assembly via a flanged joint, sealed with a metal
gasket and secured with locknuts and studs.
The forward and rear sections are joined by a silencer. The silencer is fabricated from stainless steel sheet to form
the body of the silencer. An end plate closes each end of the silencer and is attached to the body with seam joints.
Perforated baffle tubes, inside the silencer, are connected to the inlet and outlet pipes on each end plate. Internal
baffle plates support the baffle tubes and, together with a stainless steel fibre packing, absorb combustion noise
as the exhaust gases pass through the silencer.
The intermediate pipe is attached by two brackets, positioned at each end of the silencer, and two mounting
rubbers to the chassis. The mounting rubber allows for ease of alignment and vibration absorption.
Tail pipe assembly
The tail pipe is of welded and fabricated construction. The tail pipe connects to the intermediate pipe with a
flanged joint secured with locknuts and sealed with a metal gasket. The pipe is shaped to locate above the rear
axle allowing clearance for axle articulation. The pipe is also curved to clear the left hand side of the fuel tank
which has a reflective shield to protect the tank from heat generated from the pipe.
A fabricated silencer is located at the rear of the tail pipe. The silencer is circular in section and is constructed from
stainless steel sheet. A baffle tube is located inside the silencer and the space around the baffle tube is packed
with a stainless steel fibre. The holes in the baffle tube allow the packing to further reduce combustion noise from
the engine. The tail pipe from the silencer is curved downwards at the rear of the vehicle and directs exhaust
gases towards the ground. The curved pipe allows the exhaust gases to be dissipated by the airflow under the
vehicle and prevents the gases from being drawn behind the vehicle.
The tail pipe is attached by a bracket, positioned forward of the silencer, and a mounting rubber to the chassis.
The mounting rubber allows ease of alignment and vibration absorption.
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