Page 145 of 1672
ENGINE - TD5
12-1-6 DESCRIPTION AND OPERATION
Cylinder head components
Page 146 of 1672

ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-7
1Camshaft carrier
2Dowel – rocker shaft to camshaft carrier (1 off)
3Cylinder head bolts (12 off)
4Rocker shaft to camshaft carrier bolts (6 off)
5Rocker shaft
6Circlips (10 off)
7EUI Rocker arms (5 off)
8Camshaft carrier to cylinder head screws (13
off)
9Finger follower (10 off)
10Valve spring collets (20 off)
11Lash adjuster (10 off)
12Valve spring retainer (10 off)
13Valve spring (10 off)
14Valve stem seal (10 off)
15Valve guide (10 off)
16Valve seat insert (10 off)
17Inlet valve (5 off)
18Exhaust valve (5 off)
19Camshaft
20Camshaft bore seal (rear)21Coolant jacket core plug
22Cylinder head block
23Water jacket threaded plug
24Engine lifting bracket (LH)
25Engine lifting bracket bolts (2 off)
26Coolant outlet elbow to cylinder head bolts (3
off)
27Coolant outlet elbow
28Coolant outlet elbow gasket
29Cylinder head gasket
30Non-return valve (not removable, integral in
cylinder head)
31Camshaft bore end cap (front)
32End cap seal
33Cylinder head to cam carrier dowel (2 off)
34Engine lifting bracket (RH)
35Engine lifting bracket bolts (2 off)
Page 147 of 1672
ENGINE - TD5
12-1-8 DESCRIPTION AND OPERATION
Camshaft cover and engine cover
Page 148 of 1672
ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-9
1Acoustic cover
2Oil filler flap
3Rear acoustic cover
4Rear acoustic cover inserts (2 off)
5Rear acoustic cover grommets (2 off)
6Rear acoustic cover screws (2 off)
7Acoustic cover grommets (3 off)
8Acoustic cover bolts (3 off)
9Camshaft cover isolators (13 off)
10Camshaft cover flange screws (13 off)
11Breather hose clip
12Breather hose
13Breather hose to breather valve clip
14Breather valve
15Camshaft cover seal
16Oil separator plate
17Oil separator plate gasket
18Camshaft cover
19Acoustic cover to camshaft cover seal
20Oil filler cap and seal
Page 149 of 1672
ENGINE - TD5
12-1-10 DESCRIPTION AND OPERATION
Camshaft timing chain components
Page 150 of 1672
ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-11
1Vacuum pump stub pipe
2Cylinder head to timing chain cover bolt
3Cylinder head to timing chain cover nut
4Cylinder head to timing chain cover stud
5Tensioner assembly pivot screw
6Tensioner adjuster
7Tensioner arm assembly
8Duplex timing chain – crankshaft to camshaft
sprocket
9Camshaft sprocket bolts (3 off)
10Camshaft sprocket
11Fixed chain guide
12Fixed guide pin
13Fixed chain guide to cylinder block screws
14Oil pump drive chain
15Oil pump sprocket
16Oil pump sprocket screw
17Crankshaft sprockets
18Bearing to viscous fan shaft
19Viscous fan to cover bearing
20Circlip
21Hub – viscous fan to bearing flange
22Timing chain cover
23Timing chain cover to crankshaft seal
24Timing cover to cylinder head screws (8 off)
Page 151 of 1672

ENGINE - TD5
12-1-12 DESCRIPTION AND OPERATION
Description
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) and on EU3 models, comply with ECD3 legislative requirements. Both models 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 engine 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:
lElectronic Unit Injectors (EUI's) controlled by an Engine Management System for precise fuel delivery under
all prevailing operating conditions.
lTurbocharging which delivers compressed air to the combustion chambers via an intercooler for improved
power output.
lFuel Cooler
lOil Cooler
lCentrifuge Oil Filter
lHydraulic Lash Adjusters with independent finger followers
Cylinder block components
The cylinder block components are described below:
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 mounting 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 gearbox 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 is included at the front and rear of the cylinder block.
Page 152 of 1672

ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-13
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.
Connecting rods
1Small-end oil holes
2Small-end bushing
3Connecting rod
4Serrated fracture
The connecting rods are machined, H-sectioned 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 models 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. The connecting rod bearing shell can be identified by having a slightly darker colouration than the
end cap bearing shell and the back of the connecting rod bearing shell has a shinier finish than the front face.
On EU3 models 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 with 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.