Page 158 of 1672

ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-19
Oil Pressure switch
The oil pressure switch is located in a port on the outlet side of the oil cooler housing. It detects when a safe operating
pressure has been reached during engine starting and initiates the illumination of a warning light in the instrument
pack if the pressure drops below a given value.
Crankshaft, sump and oil pump components
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.
The 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.
Page 168 of 1672
ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-29
Lubrication circuit
Cylinder block flow
1Oil squirt jets (5 off)
2Main oil delivery gallery
3Inflow from oil cooler housing
4Flow to oil cooler / filters (from oil pump via
cylinder block)
5Sump
6Oil pick-up pipe
7Flow from oil pump (relief-valve in housing)
8Oil pump9Cross-drilling supply to main and crankshaft
bearings
10To cylinder head
Page 169 of 1672

ENGINE - TD5
12-1-30 DESCRIPTION AND OPERATION
Oil from the sump is drawn up through a two-piece plastic pick-up which contains a mesh to siphon any relatively large
pieces of material which could cause damage to the pump. The head of the pick-up is centrally immersed in the sump
oil and oil is delivered to the inlet side of the eccentric rotor pump through a gallery in the stiffener plate.
Pressurised oil from the pump is passed through to the cylinder block where it is delivered to the centrifuge filter and
full-flow filter via a port in the RH cylinder block which interfaces with a port in the centre gallery of the oil cooler
housing. The oil pump contains an oil pressure relief valve which opens to allow oil to be recirculated back around the
pump if the oil pressure increases to a high enough level.
10% of the oil flow from the pump is diverted through the centrifuge filter and returned to the sump via the centrifuge
filter drain tube. The remaining 90% of the oil passes through the standard full-flow filter to the main oil gallery in the
cylinder block.
Page 170 of 1672
ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-31
Oil cooler / Filter flow (thermostat open)
1To cylinder block main gallery (from rear of oil
cooler housing)
2Oil cooler housing
3Oil pressure switch
4Full-flow filter
5Centrifuge filter6Return to sump
7Flow from oil pump (via cylinder block)
8Oil cooler matrix
Page 171 of 1672

ENGINE - TD5
12-1-32 DESCRIPTION AND OPERATION
When the engine temperature is below 74° C, the thermostat in the full-flow filter housing is closed and a proportion
of the oil flow to the main oil gallery is diverted to the oil cooler to supply an oil feed to the turbocharger bearings. Oil
passes through the oil cooler to the front gallery in the oil cooler housing where there is a tapping to connect the feed
pipe to the turbocharger. Oil used by the turbocharger bearings is returned to the sump through an oil drain pipe which
connects to a port in the LH side of the cylinder block.
The remainder of the oil flow leaving the full-flow filter outlet is passed into the cylinder block via a port at the rear of
oil cooler rear gallery.
When the oil temperature rises above 74
° C the thermostat in the full-flow filter adaptor housing begins to open to
allow a proportion of the oil from the full-flow filter to pass through the oil cooler before it reaches the main oil gallery
in the cylinder block. In this instance, oil supply to the turbocharger bearings is fed directly from the full-flow filter
without first passing through the oil cooler. Between 74
° C and 88° C the thermostat valve plunger opens by about
9mm to allow proportionally more oil to flow through the oil cooler before being passed to the cylinder block main oil
delivery gallery. Above 88
°C the thermostat valve continues to open by about 1mm for every 10° C increase in
temperature until the valve is fully open, when all the oil flow to the cylinder block is forced to pass to the cylinder block
via the oil cooler.
An oil pressure switch is located in a port in the rear gallery of the oil cooler housing to sense the oil pressure level
before flow enters the main oil gallery in the engine block. A warning lamp in the instrument cluster is switched on if
the oil pressure is detected as being too low.
+ INSTRUMENTS, DESCRIPTION AND OPERATION, Description.
Drillings from the cylinder block main oil gallery direct oil to the crankshaft main bearings and cross drillings in the
crankshaft direct oil to the big-end bearings. An additional five drillings in the cylinder block supply oil at reduced
pressure to the oil squirt jets for piston cooling and gudgeon pin lubrication.
Oil supply from the cylinder block is then passed to the cylinder head galleries through a non-return valve which is
included as an integral item in the lower face of the cylinder head.
Page 192 of 1672

ENGINE - TD5
REPAIRS 12-1-53
Mounting - front - LH
$% 12.45.01
Remove
1.Remove centrifuge assembly.
+ ENGINE - Td5, REPAIRS, Gasket -
centrifuge oil drain pipe.
2.Remove 3 bolts, remove oil filter adaptor
housing and discard gasket.
3.Fit suitable lifting chains to support engine.
4.With assistance remove 2 bolts securing
engine mounting to chassis.
5.Remove 4 bolts securing engine mounting
bracket to cylinder block.
6.Remove nut securing mounting to mounting
bracket.
7.Remove mounting and mounting bracket.
8.Remove mounting shield.
Refit
1.Fit shield to mounting. 2.Fit mounting and mounting bracket.
3.Fit mounting bracket to cylinder block and
tighten – bolts securing front LH engine
mounting bracket to cylinder block to 48 Nm (35
lbf.ft).
4.With assistance, fit mounting to chassis and
tighten – bolts securing front LH engine
mounting to chassis to 85 Nm (63 lbf.ft).
5.Fit mounting to mounting bracket and tighten –
nut securing front LH mounting to mounting
bracket to 85 Nm (63 lbf.ft).
6.Remove engine support chains.
7.Clean oil filter adaptor housing and mating
face.
8.Fit oil filter adaptor housing to oil cooler
housing and tighten bolts to 25 Nm (18 lbf.ft).
9.Fit centrifuge assembly.
+ ENGINE - Td5, REPAIRS, Gasket -
centrifuge oil drain pipe.
Page 196 of 1672
ENGINE - TD5
REPAIRS 12-1-57
Filter - oil
$% 12.60.04
Remove
1.Remove 3 bolts and remove engine acoustic
cover.
2.Remove 3 bolts and remove exhaust manifold
heat shield.
3.Clean area around filter head and place a
container beneath engine.
4.Using a strap wrench, unscrew and discard
filter. Refit
1.Clean mating face of filter head.
2.Lubricate sealing ring of new filter with clean
engine oil.
3.Fit filter and tighten by hand until it seats then
tighten a further three-quarters of a turn.
4.Start and run engine to check for leaks.
5.Stop engine, wait a few minutes, then check oil
level.
6.Top up engine oil.
+ MAINTENANCE, PROCEDURES,
Engine oil - diesel engine.
7.Position exhaust manifold heatshield and
tighten M6 bolts to 9 Nm (7 lbf.ft) and M8 bolts
to 25 Nm (18 lbf.ft).
8.Fit engine acoustic cover and secure with
fixings.
Page 202 of 1672

ENGINE - TD5
REPAIRS 12-1-63
Refit
1.Clean oil pressure switch threads.
2.Fit oil pressure switch and tighten to 15 Nm (11
lbf.ft).
3.Connect multiplug to oil pressure switch.
4.Position exhaust manifold heatshield and
tighten M6 bolts to 9 Nm (7 lbf.ft) and M8 bolts
to 25 Nm (18 lbf.ft).
5.Fit and secure engine acoustic cover.
6.Top up engine oil.
+ MAINTENANCE, PROCEDURES,
Engine oil - diesel engine.
Cooler - engine oil
$% 12.60.68
Remove
1.Drain cooling system.
+ COOLING SYSTEM - Td5,
ADJUSTMENTS, Drain and refill.
2.Remove centrifuge assembly.
+ ENGINE - Td5, REPAIRS, Gasket -
centrifuge oil drain pipe.
3.Remove clutch housing bolt and release
coolant pipe from rear of engine.
4.Release clip and coolant hose from oil cooler.
5.Disconnect multiplug from oil pressure switch.
6.Remove full-flow oil filter element using a
suitable strap wrench.
7.Remove 3 bolts, remove oil filter adaptor
housing and discard gasket.
8.Remove 7 bolts, remove oil cooler and discard
gasket.
9.Remove oil pressure switch.