1999 LAND ROVER DEFENDER shaft

12ENGINE
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DESCRIPTION AND OPERATION GENERAL
The Td5 diesel engine is a 2.5 litre, 5 cylinder, in-line direct injection unit having 2 valves per cylinder, operated by
a single overhead camshaft. The engine emissions on pre EU3 models comply with ECD2 (European Commission
Directive) legislative requirements. EU3 models comply with ECD3 legislative requirements. Both units employ
electronic engine management control, positive crankcase ventilation and exhaust gas recirculation to limit the
emission of pollutants. The unit is water cooled and turbo-charged and is controlled by an electronic engine
management system.
The cylinder block is a monobloc cast iron construction with an aluminium stiffening plate fitted to the bottom of the
cylinder block to improve lower structure rigidity. The cylinder head and sump are cast aluminium. An acoustic
cover is fitted over the upper engine to reduce engine generated noise.
The engine utilises the following features:
Electronic Unit Injectors (EUI’s)controlled by an Engine Management System for precise fuel delivery under
all prevailing operating conditions.
Turbochargingwhich delivers compressed air to the combustion chambers via an intercooler for improved
power output.
Fuel Cooler
Oil Cooler
Centrifuge Oil Filter
Hydraulic Lash Adjusterswith independent finger followers
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ENGINE
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DESCRIPTION AND OPERATION CYLINDER BLOCK
The cylinders and crankcase are contained in a single cast iron construction. The cylinders are direct bored and
plateau honed with lubrication oil supplied via lubrication jets for piston and gudgeon pin lubrication and cooling. It
is not possible to rebore the cylinder block if the cylinders become worn or damaged. Three metal core plugs are
fitted to the three centre cylinders on the right hand side of the cylinder block.
Lubrication oil is distributed throughout the block via the main oil gallery to critical moving parts through channels
bored in the block which divert oil to the main and big-end bearings via oil holes machined into the crankshaft. Oil
is also supplied from the cylinder block main gallery to the five lubrication jets which cool and lubricate the piston
and gudgeon pins. Plugs are used to seal both ends of the main oil gallery at front and rear of the engine block.
An oil cooler is fitted to the LH side of the engine block; ports in the oil cooler assembly mate with ports in the
cylinder block to facilitate coolant flow. Oil is diverted through the oil cooler, centrifuge filter and full-flow filter
before supplying the main oil gallery. A tapping in the oil filter housing provides a lubrication source for the
turbocharger bearings and an oil pressure switch is included in a tapping in the oil cooler housing which
determines whether sufficient oil pressure is available to provide engine lubrication and cooling.
Cylinder cooling is achieved by water circulating through chambers in the engine block casting. A threaded coolant
jacket plug is located at the front RH side of the cylinder block.
Cast brackets are bolted to both sides of the engine block for mounting the engine to the chassis on the LH and
RH hydramount studs.
The gearbox bolts directly to the engine block; a gearbox shim plate is located between the adjoining faces of the
gearbox and the flywheel side of the engine block and is fixed to the rear of the engine block by two bolts. Two
hollow metal dowels locate the rear of the cylinder block to the shim plate. The gearbox casing provides the
mounting for the starter motor.
A port is included at the rear left hand side of the cylinder block which connects to the turbocharger oil drain pipe
to return lubrication oil to the sump. A plug sealing the lubrication cross-drilling gallery is located at the front right
hand side of the cylinder block and plugs for the main lubrication gallery are located at the front and rear of the
cylinder block. Two plastic dowels are used to locate the cylinder head to the cylinder block and must be replaced
every time the cylinder head is removed from the cylinder block.
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12ENGINE
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DESCRIPTION AND OPERATION Connecting rods
1.Small-end oil holes
2.Small-end bushing3.Connecting rod
4.Serrated fracture
The connecting rods are machined, H-section steel forgings which feature a fracture-split at the big-end between
the connecting rod and the bearing cap. The connecting rod features a serrated fracture across the big-end at
right angles to the length of the connecting rod, this forms a unique mating surface between the connecting rod
and the fractured end which is used as the big-end cap. The use of a fracture split in the big-end of the connecting
rod ensures a perfect match for assembly on the crankshaft bearing journals and provides the connecting rod with
strong resistance to lateral movement.
The end-cap fixing bolts are offset to ensure that the cap is fitted to the connecting rod in the correct orientation. If
the end-cap is fitted incorrectly and the end-cap bolts tightened, the connecting rod must be replaced, since the
matching serrations will have been damaged.
The big-end bearing shells are plain split halves without location tags. On EU2 vehicles the two halves of the
bearing shells are of different construction. The upper half bearing shell fitted to the connecting rod is treated
using the sputtering process to improve its resistance to wear. The connecting rod bearing shell can be identified
by having a slighter darker colouration than the big-end bearing cap shell, and the back face of the connecting rod
bearing shell has a shinier finish than the front face.
On EU3 vehicles both bearing shells are of the same construction as the connecting rod bearing shell.
The small-end of the connecting rod has a bushed solid eye which is free to move on the gudgeon pin, the
bushing is a hand push, interference fit. The steel bushing has two slots machined in its upper surface for
providing oil lubrication to the moving surface of the gudgeon pin. The oil slots must be correctly aligned to the oil
slots provided in the small end of the connecting rod. The small-end lubrication is supplied by squirt feed from the
piston lubrication jets.
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12ENGINE
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DESCRIPTION AND OPERATION CRANKSHAFT, SUMP AND OIL PUMP
The crankshaft, sump and oil pump components are described below:
Sump
The sump is a wet-type, of aluminium construction and is sealed to the engine block by means of a rubber gasket
and twenty fixing bolts. The four bolts at the gearbox end of the sump are longer than the other sixteen bolts.
The sump gasket incorporates compression limiters (integrated metal sleeves) at the bolt holes, which are
included to prevent distortion of the gasket when the sump to cylinder block bolts are being tightened.
An oil drain plug is fitted at the bottom of the oil sump reservoir. An oil return drain pipe is also attached to the oil
sump which returns oil from the centrifugal filter.
Stiffener Plate
The stiffener plate assembly provides lower engine block rigidity and utilises dowels to align it to the bottom of the
cylinder block. A rotary oil pump is integral with the stiffener plate and an oil pick-up and strainer assembly is fitted
to the underside of the stiffener plate. The stiffener and oil pump assembly is secured to the cylinder block by 22
bolts.
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12ENGINE
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DESCRIPTION AND OPERATION Crankshaft
1.Front end to crankshaft sprocket
2.Oil supply cross-drillings
3.Main journals4.Big-end journals
5.Rear end to flywheel
The crankshaft is constructed from cast iron and is surface-hardened. The areas between the crankshaft journals
and the adjoining webs and balance weights are compressed using the cold roll process to form journal fillets.
Cross-drillings in the crankshaft between adjoining main and big-end bearings are used to divert lubrication oil to
the big-end bearings.
A torsional vibration damper is attached to the crankshaft pulley by three bolts.
The crankshaft is carried in six main bearings, with end-float being controlled by thrust washers positioned on both
sides of No. 3 main bearing.
Main bearings
There are six main bearings used to carry the crankshaft. Each of the bearing caps are of cast iron construction
and are attached to the cylinder block by two bolts.
The bearing shells are of the split cylindrical type. The upper half bearing shells are grooved to facilitate the supply
of lubrication oil to the bearings and fit into a recess in the underside of the cylinder block. The lower half bearing
shells are smooth and fit into the bearing caps.
Steel-backed, thrust washers are included at each side of No. 3 main bearing to control crankshaft end-float. One
side of each of the thrust washers is grooved, the grooved side of each of the thrust washers is fitted facing
outward from No. 3 main bearing.
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ENGINE
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DESCRIPTION AND OPERATION CYLINDER HEAD COMPONENTS
The cylinder head components are described below:
Cylinder head
The cylinder head is of aluminium construction. It is not possible to reface the cylinder head if it becomes worn or
damaged. An alloy camshaft carrier is bolted directly to the upper surface of the cylinder head. Two dowels are
included in the cylinder head upper face for correct location of the camshaft carrier.
The EU3 cylinder head has a single internal fuel rail for delivering fuel to the injectors and an external fuel pipe for
returning spill fuel back to the fuel connector block. Therefore, pre EU3 and EU3 cylinder heads are not
interchangeable.
CAUTION: The cylinder head incorporates drillings for the fuel injection system, any
contamination which enters these drillings could cause engine running problems or injector
failure. It is therefore, essential that absolute cleanliness is maintained when carrying out work on
the cylinder head.
The camshaft carrier and cylinder head assembly is attached to the cylinder block by twelve cylinder head
retaining bolts which pass through the camshaft carrier and the cylinder head to secure the assembly to the
cylinder block.
CAUTION: The valve heads, tips of the injectors and glow plugs protrude below the face of the
cylinder head and will be damaged if the cylinder head is stored face down.
The camshaft is located between the cylinder head and the camshaft carrier, and the bearing journals are line
bored between the two components to form a matched pair.
CAUTION: Always fit plugs to open connections to prevent contamination.
The valve guides and valve seat inserts are sintered components which are an interference fit to the cylinder
head. The cylinder head machining also provide the locations for the electronic unit injectors, glow plugs, hydraulic
lash adjusters, finger followers and low pressure fuel rail.
Cooling to the cylinder head is provided by coolant flow through a water jacket machined into the cylinder head.
Drillings through the block provide lubrication channels for pressurised oil supply to cylinder head components
such as the lash adjusters, finger followers, rocker arms and camshaft bearings.
A coolant outlet elbow is fitted to the front LH side of the cylinder head to allow flow of coolant from the cylinder
head back to the radiator. A metal gasket is used to seal the joint between the water outlet elbow and the cylinder
head. A coolant temperature sensor is located in a port in the side of the water outlet elbow for monitoring coolant
temperature.
A stub pipe is connected at the front RH side of the cylinder block above the timing cover which connects a pipe to
supply oil to the vacuum pump. The timing chain tensioner adjuster is screwed in a thread in the cylinder head at a
location on the front RH side of the engine below the oil feed port for the vacuum pump.
An access hole for the camshaft gear is included at the front of the cylinder head which is sealed with a plastic
plug and rubber’O’ring. A press-fit core plug for the chain chest is located on the front face of the cylinder head.
A press-fit core plug for the cylinder head water jacket is located at the rear of the cylinder head and a threaded
brass plug for the water jacket is located on the LH side of the cylinder head beneath the exhaust manifold
assembly.
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12ENGINE
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DESCRIPTION AND OPERATION Fuel connector block
Type A - Non EU3 Models - Engine Serial No. Prefixes 10P to 14P
Type B - EU3 Models - Engine Serial No. Prefixes 15P to 19P
1.Fuel connector block assembly
2.Outlet stub pipe
3.Stub pipe - to fuel cooler4.Fuel temperature sensor
5.Fuel pressure regulator
6.Spill return fuel connection (EU3 models only)
A cast and machined aluminium alloy fuel connector block assembly is located at the rear RH side of the cylinder
head, attached by three flanged bolts. A metal gasket is used to seal the faces between the fuel connector block
and the cylinder head, which must be replaced every time the fuel connector block is removed.
CAUTION: The cylinder head incorporates drillings for the fuel injection system, any
contamination which enters these drillings could cause engine running problems or injector
failure. It is therefore, essential that absolute cleanliness is maintained when carrying out work on
the cylinder head.
CAUTION: The valve heads, tips of the injectors and glow plugs protrude below the face of the
cylinder head and will be damaged if the cylinder head is stored face down.
Camshaft carrier
The cast aluminium alloy camshaft carrier is bolted to the cylinder head by thirteen screws. The camshaft carrier
and cylinder head assembly is attached to the cylinder block by twelve cylinder head retaining bolts which pass
through the camshaft carrier and the cylinder head to secure the assembly to the cylinder block.
The carrier is machined together with the cylinder head to form a matched pair for carrying the camshaft.
Non-return valve
A non-return valve is located at the front, bottom LH side of the cylinder head. The non-return valve prevents oil
from draining from the lash adjusters and is an integral component within the cylinder head and is
non-serviceable.
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ENGINE
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DESCRIPTION AND OPERATION Camshaft
The camshaft is machined from cast steel and is located between the cylinder head and the camshaft carrier and
the six bearing journals are line bored between the two components to form a matched pair. The machined
camshaft has 15 lobes. Ten lobes operate the inlet and exhaust valves through hydraulic lash adjusters and finger
followers which are located below the camshaft. Five larger lobes activate the injector rockers which are located
above the camshaft on the rocker shaft and are used to generate fuel pressure in the EUI injectors.
The camshaft sprocket is driven via a Duplex chain connected to the crankshaft sprocket at a speed ratio of 2:1.
The camshaft sprocket is fixed to the front end of the camshaft by three bolts.
Camshaft lubrication is by splash and channel fed via pressurised oil flowing through galleries in the cylinder head.
Rocker shaft and rocker arms
Type A - Non EU3 Models - Engine Serial No. Prefixes 10P to 14P
Type B - EU3 Models - Engine Serial No. Prefixes 15P to 19p
1.Rocker arm adjusting screw
2.Rocker shaft
3.Rocker arm
4.EUI pin and roller assembly
5.Roller pin retention slug6.Camshaft lobe
7.Injector spring
8.Injector push-rod
9.Adjusting nut
The hollow rocker shaft is located in the camshaft carrier in six fixed mountings which sit above the camshaft. Six
bolts are used to lock the rocker shaft to the camshaft carrier. The front rocker shaft bearing has a ring dowel
located at the front rocker shaft mounting of the camshaft carrier for rocker shaft alignment. Two circlips hold each
rocker arm in position at the relevant positions on the rocker shaft.
CAUTION: The rocker shaft from a pre EU3 engine must not be fitted to an EU3 engine. This is
because the stroke of the EU3 injector has increased which requires the rocker to articulate over a
larger angle.
The camshaft end of each rocker arm features a roller which is free to rotate about a pin which passes through
two webs in the rocker arm, the roller pins are held in place by an interference fit retention slug passing through a
hole in the front web of each rocker arm.
To correctly function against the higher loads of the EU3 engine the geometry of the contact between the injector
pushrod and rocker arm adjusting screw has been modified. Both designs of adjusting screw are separately
available, with the EU3 version identified by an engraved dimple on the slotted end.
Rocker shaft and rocker arm lubrication is by splash and channel fed via pressurised oil flowing through galleries
in the cylinder head and through the rocker shaft.
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