AUX FORD SIERRA 1992 2.G SOHC Engines User Guide

chamfered inner edge which should fit against
the shoulder on the flywheel. When hot
enough, place the gear in position quickly,
tapping it home if necessary, and let it cool
naturally without quenching in any way.
Refitting
9Commence refitting of the
flywheel/driveplate by refitting the engine
adapter plate to the dowels on the rear of the
cylinder block, where applicable.
10Ensure that the mating faces are clean,
then locate the flywheel/driveplate on the rear
of the crankshaft, aligning the previously
made marks (see illustration).
11Coat the threads of the securing bolts
with a liquid thread-locking agent, then insert
the bolts. Note that the manufacturers rec-
ommend the use of new bolts. Where
applicable refit the reinforcing plate(s) on
models with A4LD type automatics12Prevent the flywheel/driveplate from
turning as described in paragraph 2, then
tighten the securing bolts to the specified
torque in a diagonal sequence (see
illustration).
13If the engine is in the vehicle, refit the
clutch or the automatic transmission, as
applicable.
Note: A new gasket will be required for
refitting if the old seal housing is removed
during this procedure.
1Remove the timing belt and the crankshaft
sprocket.
2If an oil seal removal tool is available, the oil
seal can be removed at this stage. It may also
be possible to remove the oil seal by drillingthe outer face and using self-tapping screws
and a pair of grips.
3If the oil seal cannot be removed as
described in paragraph 2, remove the sump
and the auxiliary shaft sprocket, then unbolt
the oil seal housing and the auxiliary shaft
front cover. Recover the gasket. The oil seal
can then be driven out from the inside of the
housing (see illustrations).
4Clean the oil seal housing, then drive in a
new seal using a suitable metal tube or
socket. Make sure that the seal lip faces into
the engine and lightly smear the lip with clean
engine oil (see illustration).
5Where applicable, refit the oil seal housing
and the auxiliary shaft front cover, using a
new gasket, and tighten the bolts. Using a
straight edge, ensure that the bottom face of
the oil seal housing is aligned with the bottom
face of the cylinder block before finally
tightening the bolts (see illustrations). Refit
the auxiliary shaft sprocket and refit the sump.
6Refit the crankshaft sprocket and timing
belt.
1Remove the flywheel/driveplate and the
engine adapter plate.
2Extract the oil seal using an oil seal removal
tool if available. It may also be possible to
remove the oil seal by drilling the outer face
and using self-tapping screws and a pair of
grips (see illustration).
28Crankshaft rear oil seal -
renewal27Crankshaft front oil seal -
renewal
SOHC engines 2A¥19
2A
27.3a Removing the crankshaft front oil
seal housing27.3b Driving the crankshaft front oil seal
from the housing
28.2 Crankshaft rear oil seal location
(arrowed)27.5b Checking the alignment of the
crankshaft front oil seal housing27.5a Crankshaft front oil seal
housing/auxiliary shaft cover gasket
located on front of cylinder block
27.4 Using a socket to fit a new crankshaft
front oil seal
26.12 Use a strap to prevent the flywheel
turning as its securing bolts are tightened26.10 Flywheel located on crankshaft

4Before fitting the new rings to the pistons,
insert them into the cylinder bore and use a
feelerblade to check that the end gaps are
within the specified limits (see illustration).
5Clean out the piston ring groove using a
piece of old piston ring as a scraper. Be
careful not to scratch the aluminium surface
of the pistons. Protect your fingers - piston
ring edges are sharp.
6Fit the oil control ring sections with the
spreader ends abutted opposite the front of the
piston. The side ring gaps should be 25 mm (1.0
in) either side of the spreader gap. Fit the
tapered lower compression ring with the ÒTOPÓ
mark towards the top of the piston and the gap
150¼ from the spreader gap, then fit the upper
compression ring with the gap 150¼ on the
other side of the spreader gap. Note that the
compression rings are coated with a
molybdenum skin which must not be damaged.
Note also that the compression rings are made
of cast iron, and will snap if expanded too far.
Removal
1With the engine removed from the vehicle,
remove the timing belt, crankshaft sprocket,
auxiliary shaft sprocket and the
flywheel/driveplate.
2Remove the pistons and connecting rods. If
no work is to be done on the pistons and
connecting rods, there is no need to push the
pistons out of the cylinder bores.
3Unbolt the crankshaft front oil seal housing
and the auxiliary shaft front cover and remove
the gasket.4Remove the oil pump and pick-up tube.
5Check the main bearing caps for
identification marks and if necessary use a
centre-punch to identify them (see
illustration).
6Before removing the crankshaft, check that
the endfloat is within the specified limits by
inserting a feeler blade between the centre
crankshaft web and the thrustwashers (see
illustration). This will indicate whether or not
new thrustwashers are required.
7Unscrew the bolts and tap off the main
bearing caps complete with bearing shells. If
the thrustwashers are to be re-used identify
them for location. Recover the sealing wedges
from either side of the rear bearing cap.
8Lift the crankshaft from the crankcase and
remove the rear oil seal. Recover the
remaining thrustwashers (see illustration).
9Extract the bearing shells, keeping them
identified for location (see illustration).
Refitting
10Commence refitting as follows.
11Wipe the bearing shell locations in the
crankcase with a soft, non-fluffy rag.
12Wipe the crankshaft journals with a soft,
non-fluffy rag.
13If the old main bearing shells are to be
renewed (not to do so is a false economy,
unless they are virtually new) fit the five upper
halves of the main bearing shells to their
location in the crankcase.
14Identify each main bearing cap and place
in order. The number is cast on to the cap and
on intermediate caps an arrow is marked
which points towards the front of the engine.
15Wipe each cap bearing shell location with
a soft non-fluffy rag. 16Fit the bearing half shell onto each main
bearing cap.
17Apply a little grease to each side of the
centre main bearing so as to retain the
thrustwashers.
18Fit the upper halves of the thrustwashers
into their grooves either side of the main
bearing. The slots must face outwards.
19Lubricate the crankshaft journals and the
upper and lower main bearing shells with
clean engine oil and locate the rear oil seal
(with lip lubricated) on the rear of the
crankshaft.
20Carefully lower the crankshaft into the
crankcase.
21Lubricate the crankshaft main bearing
journals again, and then fit No 1 bearing cap. Fit
the two securing bolts but do not tighten yet.
22Make sure that the mating faces are
clean, then apply sealant (Loctite 518 or
equivalent) to the areas on the rear main
bearing cap shown (see illustration).
23Fit the rear main bearing cap. Fit the two
securing bolts but as before do not tighten yet.
24Apply a little grease to either side of the
centre main bearing cap so as to retain the
thrustwashers. Fit the thrustwashers with the
tag located in the groove and the slots facing
outwards (see illustration).
25Fit the centre main bearing cap and the
two securing bolts, then refit the intermediate
main bearing caps. Make sure that the arrows
point towards the front of the engine.
26Lightly tighten all main bearing cap
securing bolts and then fully tighten in a
progressive manner to the specified torque
wrench setting.
27Check that the crankshaft rotates freely.
Some stiffness is to be expected with new
34Crankshaft and main bearings
- removal and refitting
SOHC engines 2A¥23
2A
34.6 Checking crankshaft endfloat
34.22 Coat the arrowed areas of the rear
main bearing cap with sealant34.9 Extract each main bearing shell34.8 Removing a thrustwasher from the
centre main bearing
34.5 Main bearing cap identification marks.
The arrow points to the front of the engine
33.4 Checking a piston ring gap at the top
of the cylinder bore

components, but there must be no tight spots
or binding.
28Check that the crankshaft endfloat is
within the specified limits by inserting a feeler
blade between the centre crankshaft web and
the thrustwashers.
29Make sure that the rear oil seal is fully
located onto its seating. Coat the rear main
bearing cap sealing wedges with sealing
compound, then press them into position
using a blunt screwdriver with the rounded
red face towards the cap (see illustration).
30Refit the oil pump and pick-up tube.
31Refit the crankshaft front oil seal housing
and the auxiliary shaft front cover using a new
gasket, and tighten the securing bolts. Smear
the lip of the oil seal with clean engine oil
before fitting; and using a straight edge, ensure
that the bottom face of the oil seal housing is
aligned with the bottom face of the cylinder
block before finally tightening the bolts.
32Refit the pistons and connecting rods.
33Refit the flywheel/driveplate and the
auxiliary shaft sprocket, crankshaft sprocket,
and timing belt.
1Examine the bearing surfaces of the
crankshaft for scratches or scoring and, using
a micrometer, check each journal and
crankpin for ovality. Where this is found to be
in excess of 0.0254 mm (0.001 in) the
crankshaft will have to be reground and
undersize bearings fitted.
2Crankshaft regrinding should be carried out
by a suitable engineering works, who will
normally supply the matching undersize main
and big-end shell bearings.
3Note that undersize bearings may already
have been fitted, either in production or by a
previous repairer. Check the markings on the
backs of the old bearing shells, and if in doubt
take them along when buying new ones.
Production undersizes are also indicated by
paint marks as follows:
White line on main bearing cap - parent bore
0.40 mm oversize
Green line on crankshaft front counterweight
- main bearing journals 0.25 mm
undersize
Green spot on counterweight - big-end
bearing journals 0.25 mm undersize4If the crankshaft endfloat is more than the
maximum specified amount, new
thrustwashers should be fitted to the centre
main bearings. These are usually supplied
together with the main and big-end bearings
on a reground crankshaft.
5An accurate method of determining bearing
wear is by the use of Plastigage. The
crankshaft is located in the main bearings
(and big-end bearings if necessary) and the
Plastigage filament located across the journal
which must be dry. The cap is then fitted and
the bolts/nuts tightened to the specified
torque. On removal of the cap the width of the
filaments is checked against a scale which
shows the bearing running clearance. This
clearance is then compared with that given in
the Specifications (see illustration).
6If the spigot bearing in the rear of the
crankshaft requires renewal, extract it with a
suitable puller. Alternatively fill it with heavy
grease and use a close fitting metal dowel
driven into the centre of the bearing. Drive the
new bearing into the crankshaft with a soft
metal drift.
1The cylinder bores must be examined for
taper, ovality, scoring and scratches. Start by
examining the top of the bores; if these are
worn, a slight ridge will be found which marks
the top of the piston ring travel. If the wear is
excessive, the engine will have had a high oil
consumption rate accompanied by blue
smoke from the exhaust.
2If available, use an inside dial gauge to
measure the bore diameter just below the
ridge and compare it with the diameter at the
bottom of the bore, which is not subject to
wear. If the difference is more than 0.152 mm
(0.006 in), the cylinders will normally require
reboring with new oversize pistons fitted.
3Proprietary oil control rings can be obtained
for fitting to the existing pistons if it is felt that
the degree of wear does not justify a rebore.
However, any improvement brought about by
such rings may be short-lived.
4If new pistons or piston rings are to be fitted
to old bores, deglaze the bores with abrasive
paper or a Òglaze busterÓ tool. The object is to
produce a light cross-hatch pattern to assistthe new rings to bed in.
5If there is a ridge at the top of the bore and
new piston rings are being fitted, either the
top piston ring must be stepped (Òridge
dodgerÓ pattern) or the ridge must be
removed with a ridge reamer. If the ridge is
left, the piston ring may hit it and break.
6Thoroughly examine the crankcase and
cylinder block for cracks and damage and use
a piece of wire to probe all oilways and
waterways to ensurethatthey are
unobstructed.
1Make a final check to ensure that
everything has been reconnected to the
engine and that no rags or tools have been left
in the engine bay.
2Check that oil and coolant levels are
correct.
3Start the engine. This may take a little
longer than usual as fuel is pumped up to the
engine.
4Check that the oil pressure light goes out
when the engine starts.
5Run the engine at a fast tickover and check
for leaks of oil, fuel or coolant. Also check
power steering and transmission fluid cooler
unions, where applicable. Some smoke and
odd smells may be experienced as assembly
lubricant burns off the exhaust manifold and
other components.
6Bring the engine to normal operating
temperature, then check the ignition timing
and the idle speed (where applicable) and
mixture.
7If splined type cylinder head bolts have
been used, stop the engine after it has been
running for 15 minutes, then remove the
crankshaft cover and tighten the cylinder
head bolts to the fourth stage given in the
Specifications, in the correct order.
8When the engine has completely cooled,
re-check the oil and coolant levels, and
check, and if necessary adjust, the valve
clearances.
9If new bearings, pistons etc have been
fitted, the engine should be run-in at reduced
speeds and loads for the first 500 miles (800
km) or so. It is beneficial to change the engine
oil and filter after this mileage.
37Initial start-up after overhaul or
major repair
36Cylinder block and bores -
examination and renovation35Crankshaft and bearings -
examination and renovation
2A¥24SOHC engines
34.24 Fitting a thrustwasher to the centre
main bearing cap35.5 Checking the width of the filament
against the scale of the packet34.29 Fitting a sealing wedge to the rear
main bearing cap