1983 FIAT UNO light

Safety First!0•5
Working on your car can be dangerous.
This page shows just some of the potential
risks and hazards, with the aim of creating a
safety-conscious attitude.
General hazards
Scalding
• Don’t remove the radiator or expansion
tank cap while the engine is hot.
• Engine oil, automatic transmission fluid or
power steering fluid may also be dangerously
hot if the engine has recently been running.
Burning
• Beware of burns from the exhaust system
and from any part of the engine. Brake discs
and drums can also be extremely hot
immediately after use.
Crushing
• When working under or near
a raised vehicle,
always
supplement the
jack with axle
stands, or use
drive-on
ramps.
Never
venture
under a car which
is only supported by a jack.
• Take care if loosening or tightening high-
torque nuts when the vehicle is on stands.
Initial loosening and final tightening should
be done with the wheels on the ground.
Fire
• Fuel is highly flammable; fuel vapour is
explosive.
• Don’t let fuel spill onto a hot engine.
• Do not smoke or allow naked lights
(including pilot lights) anywhere near a
vehicle being worked on. Also beware of
creating sparks
(electrically or by use of tools).
• Fuel vapour is heavier than air, so don’t
work on the fuel system with the vehicle over
an inspection pit.
• Another cause of fire is an electrical
overload or short-circuit. Take care when
repairing or modifying the vehicle wiring.
• Keep a fire extinguisher handy, of a type
suitable for use on fuel and electrical fires.
Electric shock
• Ignition HT
voltage can be
dangerous,
especially to
people with heart
problems or a
pacemaker. Don’t
work on or near the
ignition system with
the engine running or
the ignition switched on.• Mains voltage is also dangerous. Make
sure that any mains-operated equipment is
correctly earthed. Mains power points should
be protected by a residual current device
(RCD) circuit breaker.
Fume or gas intoxication
• Exhaust fumes are
poisonous; they often
contain carbon
monoxide, which is
rapidly fatal if inhaled.
Never run the
engine in a
confined space
such as a garage
with the doors shut.
• Fuel vapour is also
poisonous, as are the vapours from some
cleaning solvents and paint thinners.
Poisonous or irritant substances
• Avoid skin contact with battery acid and
with any fuel, fluid or lubricant, especially
antifreeze, brake hydraulic fluid and Diesel
fuel. Don’t syphon them by mouth. If such a
substance is swallowed or gets into the eyes,
seek medical advice.
• Prolonged contact with used engine oil can
cause skin cancer. Wear gloves or use a
barrier cream if necessary. Change out of oil-
soaked clothes and do not keep oily rags in
your pocket.
• Air conditioning refrigerant forms a
poisonous gas if exposed to a naked flame
(including a cigarette). It can also cause skin
burns on contact.
Asbestos
• Asbestos dust can cause cancer if inhaled
or swallowed. Asbestos may be found in
gaskets and in brake and clutch linings.
When dealing with such components it is
safest to assume that they contain asbestos.
Special hazards
Hydrofluoric acid
• This extremely corrosive acid is formed
when certain types of synthetic rubber, found
in some O-rings, oil seals, fuel hoses etc, are
exposed to temperatures above 400
0C. The
rubber changes into a charred or sticky
substance containing the acid. Once formed,
the acid remains dangerous for years. If it
gets onto the skin, it may be necessary to
amputate the limb concerned.
• When dealing with a vehicle which has
suffered a fire, or with components salvaged
from such a vehicle, wear protective gloves
and discard them after use.
The battery
• Batteries contain sulphuric acid, which
attacks clothing, eyes and skin. Take care
when topping-up or carrying the battery.
• The hydrogen gas given off by the battery
is highly explosive. Never cause a spark or
allow a naked light nearby. Be careful when
connecting and disconnecting battery
chargers or jump leads.
Air bags
• Air bags can cause injury if they go off
accidentally. Take care when removing the
steering wheel and/or facia. Special storage
instructions may apply.
Diesel injection equipment
• Diesel injection pumps supply fuel at very
high pressure. Take care when working on
the fuel injectors and fuel pipes.
Warning: Never expose the hands,
face or any other part of the body
to injector spray; the fuel can
penetrate the skin with potentially fatal
results.
Remember...
DO
• Do use eye protection when using power
tools, and when working under the vehicle.
• Do wear gloves or use barrier cream to
protect your hands when necessary.
• Do get someone to check periodically
that all is well when working alone on the
vehicle.
• Do keep loose clothing and long hair well
out of the way of moving mechanical parts.
• Do remove rings, wristwatch etc, before
working on the vehicle – especially the
electrical system.
• Do ensure that any lifting or jacking
equipment has a safe working load rating
adequate for the job.
A few tips
DON’T
• Don’t attempt to lift a heavy component
which may be beyond your capability – get
assistance.
• Don’t rush to finish a job, or take
unverified short cuts.
• Don’t use ill-fitting tools which may slip
and cause injury.
• Don’t leave tools or parts lying around
where someone can trip over them. Mop
up oil and fuel spills at once.
• Don’t allow children or pets to play in or
near a vehicle being worked on.

Roadside Repairs0•7
Connect one end of the red jump lead to
the positive (+) terminal of the flat
batteryConnect the other end of the red lead to
the positive (+) terminal of the booster
battery.Connect one end of the black jump lead
to the negative (-) terminal of the
booster battery
Connect the other end of the black
jump lead to a bolt or bracket on the
engine block, well away from the
battery, on the vehicle to be started.
–
+
+
–
123
4
Make sure that the jump leads will not
come into contact with the fan, drive-
belts or other moving parts of the
engine.5
Start the engine using the booster
battery, then with the engine running at
idle speed, disconnect the jump leads in
the reverse order of connection.6
Jump starting will get you out
of trouble, but you must correct
whatever made the battery go
flat in the first place. There are
three possibilities:
1The battery has been drained by
repeated attempts to start, or by
leaving the lights on.
2The charging system is not working
properly (alternator drivebelt slack
or broken, alternator wiring fault or
alternator itself faulty).
3The battery itself is at fault
(electrolyte low, or battery worn out).
Booster battery (jump) starting
When jump-starting a car using a
booster battery, observe the following
precautions:
4Before connecting the booster
battery, make sure that the ignition is
switched off.
4Ensure that all electrical equipment
(lights, heater, wipers, etc) is
switched off.4Make sure that the booster battery is
the same voltage as the discharged
one in the vehicle.
4If the battery is being jump-started
from the battery in another vehicle,
the two vehcles MUST NOT TOUCH
each other.
4Make sure that the transmission is in
neutral (or PARK, in the case of
automatic transmission).
Jump starting

0•8Roadside Repairs
To avoid repetition, the procedure for
raising the vehicle, in order to carry out work
under it, is not included before each relevant
operation described in this Manual.
It is to be preferred, and it is certainly
recommended, that the vehicle is positioned
over an inspection pit or raised on a lift. Where
these facilities are not available, use ramps or
jack up the vehicle strictly in accordance with
the following guide. Once the vehicle is raised,
supplement the jack with axle stands.
Jacking
The jack supplied with the car should only
be used to change a wheel. Do not use this
jack when overhaul or repair work is being
carried out; employ a hydraulic or screw jack
and supplement it with axle stands.
Jacking points are located under the sills
for use with the jack supplied.To raise the front end with a garage jack,
locate the jack under the transmission lower
mounting, just below and slightly to the rear of
the transmission oil drain plug. Protect the
mounting by placing a block of wood between
the jack head and the mounting.
To raise the rear of the car, the jack should
be placed under the spare wheel housing as
far to the rear as possible. Place a wooden
bearer between the jack head and the
housing.
Towing
When being towed, use the left-hand front
towing eye.
When towing another vehicle, use the rear
towing eye adjacent to the exhaust tailpipe.
When being towed, remember that the
brake pedal will require heavier pressure due
to lack of servo assistance. Always turn theignition key to MAR to retain the steering in
the unlocked position.
Wheel changing
With the car on firm level ground, apply the
handbrake fully. Remove the hub cap or
wheel trim, if fitted.
Release, but do not remove, the bolts.
Chock the front and rear of the opposite
roadwheel and then raise the car using the sill
jack supplied with the car if it is being done at
the roadside. Alternatively use a workshop
jack supplemented with axle stands.
Remove the wheel bolts, change the wheel
and screw in the bolts finger tight. It is
recommended that the bolt threads are
smeared with multi-purpose grease. Lower
the car, remove the jack and tighten the wheel
bolts to the specified torque. Refit any wheel
trim that was removed.
Spare wheel and jack stowage
Front tow hook Rear tow hook
Jacking, towing and wheel changing

0•10Routine maintenance
Maintenance is essential for ensuring safety and desirable for the
purpose of getting the best in terms of performance and economy
from the car. Over the years the need for periodic lubrication has been
greatly reduced if not totally eliminated. This has unfortunately tended
to lead some owners to think that because no such action is required
the items either no longer exist or will last forever. This is certainly not
the case; it is essential to carry out regular visual examinations as
comprehensively as possible in order to spot any possible defects at
an early stage before they develop into major and expensive repairs.
For information applicable to later models, see Supplement.
Every 250 miles (400 km), weekly,
or before a long journey
m mCheck engine oil level
m mCheck brake reservoir fluid level
m mCheck tyre pressures
m mCheck operation of all lights and horn
m mTop up washer fluid reservoirs, adding a screen
wash, and check operation of washers and wipers
m mCheck coolant level
m mCheck battery electrolyte level
Every 6000 miles (10 000 km)
or six months, whichever comes first
m mRenew engine oil and filter (Chapter 1, Section 2)
m mCheck drivebelt tension (Chapter 2, Section 8)
m mCheck carburettor idle speed and mixture
adjustments (Chapter 3)
m mCheck contact points and dwell angle (mechanical
breaker distributors) (Chapter 4, Section 3)
m mCheck tyre tread wear (Chapter 7, Section 7)
m mCheck disc pads for wear (Chapter 8, Section 3)
Every 36 000 miles (60 000 km)
or three years, whichever comes first
m mRenew the timing belt - 1116 and 1299/1301 cc
(Chapter 1, Section 28)
m mCheck exhaust system for corrosion (Chapter 3,
Section 19)
m mRenew contact breaker points and adjust dwell
angle (mechanical breaker distributors) (Chapter 4,
Section 3)
m mCheck and adjust ignition timing (Chapter 4,
Section 4)
m mRenew spark plugs (Chapter 4, Section 11)
m mCheck clutch adjustment (Chapter 5, Section 2)
m mCheck transmission oil level (Chapter 6, Section 2)
m mCheck driveshaft and steering rack gaiters for splits
(Chapters 7 and 10)
m mCheck rear brake shoe linings for wear (Chapter 8,
Section 4)
m mCheck handbrake travel (Chapter 8, Section 16)
m mCheck headlamp beam alignment (Chapter 9,
Section 17)
m mCheck balljoints for wear (Chapter 10, Section 2)
m mCheck front wheel alignment (Chapter 10, Section 8)
m mCheck suspension bushes for wear (Chapter 11,
Section 2)
m mCheck seat belts for fraying (Chapter 12, Section 23)
m mLubricate controls, hinges and locks
Every 24 000 miles (40 000 km)
or two years, whichever comes first
m mRenew coolant anti-freeze mixture (Chapter 2,
Section 3)
m mRenew transmission oil (Chapter 6, Section 2)
m mRenew brake hydraulic fluid (Chapter 8, Section 12)
m mCheck for underbody corrosion and clean out door
and sill drain holes (Chapter 12, Section 2)
Every 12 000 miles (20 000 km) or
12 months, whichever comes first
m mCheck and adjust valve clearances (Chapter 1,
Sections 5 and 26)
m mRenew air cleaner element (Chapter 3, Section 2)

Cylinder head and valves
Material (cylinder head) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Light alloy
Maximum distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05 mm (0.002 in)
Valve guide bore in head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.950 to 12.977 mm (0.5099 to 0.5109 in)
Valve guide outside diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.010 to 13.030 mm (0.5122 to 0.5130 in)
Valve guide oversizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5, 0.10, 0.25 mm (0.002, 0.004, 0.010 in)
Inside diameter of valve guide (reamed) . . . . . . . . . . . . . . . . . . . . . . . . . 7.022 to 7.040 mm (0.2765 to 0.2772 in)
Guide fit in head (interference) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.033 to 0.080 mm (0.0013 to 0.0032 in)
Valve stem diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.982 to 7.000 mm (0.2748 to 0.2756 in)
Maximum clearance (valve stem to guide) . . . . . . . . . . . . . . . . . . . . . . . 0.022 to 0.058 mm (0.0009 to 0.0023 in)
Valve seat angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44º 55’ to 45º 05’
Valve face angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45º 25’ to 45º 35’
Valve head diameter:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.0 mm (1.1417 in)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26.0 mm (1.0236 in)
Contact band (valve to seat) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 to 1.5 mm (0.0512 to 0.0591 in)
Valve clearance:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15 mm (0.006 in)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20 mm (0.008 in)
For timing check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.60 mm (0.024 in)
Valve timing:
Inlet valve:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7º BTDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36º ABDC
Exhaust valve:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5º ATDC
Lubrication system
Oil pump type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gear, driven by shaft from camshaft
Tooth tip to body clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05 to 0.14 mm (0.0020 to 0.0055 in)
Gear endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.020 to 0.105 mm (0.0008 to 0.0041 in)
Oil pressure at normal operating temperature and average road/
engine speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.94 to 3.92 bar (42 to 57 lbf/ in
2)
Oil capacity (with filter change) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.42 litre (6.0 pint)
Oil type/specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multigrade engine oil, viscosity SAE 15W/40
Oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion C101
Torque wrench settingsNm lbf ft
Cylinder head bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 22
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 43.5
Camshaft sprocket bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Main bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 51
Big-end bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 30
Crankshaft pulley nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 72
Flywheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 32
Rocker pedestal nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 29
Engine mounting bracket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Engine mounting centre nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Exhaust manifold nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Temperature sender switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Driveshaft to hub nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 200
Hub carrier to strut clamp bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Roadwheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 63
Brake caliper mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 39
Tie-rod end balljoint nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 25
Driveshaft inboard boot retainer bolts . . . . . . . . . . . . . . . . . . . . . . . . . . 9 7
Engine – general 1•3
1

Crankshaft
Journal diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.785 to 50.805 mm (1.9994 to 2.0002 in)
Standard main bearing shell thickness . . . . . . . . . . . . . . . . . . . . . . . . . . 1.825 to 1.831 mm (0.0719 to 0.0721 in)
Undersizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.254, 0.508, 0.762, 1.016 mm (0.010. 0.020, 0.030, 0.040 in)
Crankshaft endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.06 to 0.26 mm (0.0024 to 0.0102 in)
Crankpin diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45.498 to 45.518 mm (1.7926 to 1.7934 in)
Standard big-end shell bearing thickness . . . . . . . . . . . . . . . . . . . . . . . 1.531 to 1.538 mm (0.0603 to 0.0606 in)
Undersizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.254, 0.508, 0.762, 1.016 mm (0.010, 0.020, 0.030, 0.040 in)
Camshaft
Number of bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Diameter of camshaft journals:
No. 1 (timing end) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.944 to 29.960 mm (1.1798 to 1.1804 in)
No. 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47.935 to 47.950 mm (1.8886 to 1.8892 in)
No. 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.135 to 48.150 mm (1.8965 to 1.8971 in)
No. 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.335 to 48.350 mm (1.9044 to 1.9050 in)
No. 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.535 to 48.550 mm (1.9122 to 1.9129 in)
Cam lift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8 mm (0.3467 in)
Camshaft bearing diameters in carrier:
No. 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.990 to 30.014 mm (1.1816 to 1.1825 in)
No. 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47.980 to 48.005 mm (1.8904 to 1.8913 in)
No. 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.180 to 48.205 mm (1.8982 to 1.8992 in)
No. 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.380 to 48.405 mm (1.9062 to 1.9072 in)
No. 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.580 to 48.605 mm (1.9141 to 1.9150 in)
Outside diameter of cam follower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36.975 to 36.995 mm (1.4568 to 1.4576 in)
Cam follower running clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.005 to 0.050 mm (0.0002 to 0.0020 in)
Lubrication system
Oil pump type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gear driven from auxiliary shaft
Tooth tip to body clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.110 to 0.180 mm (0.0043 to 0.0071 in)
Gear endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.020 to 0.105 mm (0.0008 to 0.0041 in)
Oil pressure at normal operating temperature and average road/
engine speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.43 to 4.9 bar (50 to 71 lbf/in
2)
Oil capacity (with filter change) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.05 litre (7.1 pint)
Oil type/specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multigrade engine oil, viscosity SAE 15W/40
Oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion C106
Cylinder head and valves
Head material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Light alloy
Maximum distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05 mm (0.002 in)
Valve guide bore in head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.950 to 13.977 mm (0.5496 to 0.5507 in)
Valve guide outside diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.040 to 14.058 mm (0.5532 to 0.5539 in)
Valve guide oversizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05, 0.10, 0.25 mm (0.002, 0.004, 0.010 in)
Inside diameter of valve guide (reamed) . . . . . . . . . . . . . . . . . . . . . . . . . 8.022 to 8.040 mm (0.3161 to 0.3168 in)
Valve guide fit in cylinder head (interference) . . . . . . . . . . . . . . . . . . . . . 0.063 to 0.108 mm (0.0025 to 0.0043 in)
Valve stem diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.974 to 7.992 mm (0.3142 to 0.3149 in)
Maximum clearance (valve stem to guide) . . . . . . . . . . . . . . . . . . . . . . . 0.030 to 0.066 mm (0.0012 to 0.0026 in)
Valve face angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45º 25’ to 45º 35’
Valve seat angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44º 55’ to 45º 05’
Valve head diameter:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35.850 to 36.150 mm (1.4125 to 1.4243 in)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30.850 to 31.450 mm (1.2155 to 1.2391 in)
Contact band (valve to seat) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 to 1.5 mm (0.0512 to 0.0591 in)
Valve clearance:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 mm (0.0158 in)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.50 mm (0.0197 in)
For timing check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.80 mm (0.0315 in)
Valve clearance adjusting shim thicknesses . . . . . . . . . . . . . . . . . . . . . 3.25 to 4.70 mm (0.128 to 0.185 in), in increments of 0.05 mm
(0.002 in)
Valve timing:
Inlet valve:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7º BTDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35º ABDC
Exhaust valve:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5º ATDC
Engine – general 1•5
1

Auxiliary shaft
Bearing internal diameter (reamed):
No. 1 (timing belt end) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35.664 to 35.684 mm (1.4052 to 1.4059 in)
No. 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.000 to 32.020 mm (1.2608 to 1.2616 in)
Shaft journal diameter:
No. 1 (timing belt end) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35.593 to 35.618 mm (1.4024 to 1.4033 in)
No. 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.940 to 31.960 mm (1.2584 to 1.2592 in)
Cylinder block and crankcase
Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cast-iron
Bore diameter:
1116 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80.000 to 80.050 mm (3.152 to 3.154 in)
1301 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86.400 to 86.450 mm (3.404 to 3.406 in)
Maximum cylinder bore taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.015 mm (0.0006 in)
Maximum cylinder bore ovality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.015 mm (0.0006 in)
Torque wrench settingsNm lbf ft
Cylinder head bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 30
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turn through 90º Turn through 90º
Stage 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turn through 90º Turn through 90º
Camshaft carrier to cylinder head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
Main bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 59
Big-end cap nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 38
Flywheel mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 61
Camshaft sprocket bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 61
Belt tensioner bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 32
Exhaust manifold nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 21
Auxiliary shaft sprocket bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 61
Flexible mounting bracket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 44
Flexible mounting centre nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Oil pressure switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 24
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Roadwheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 63
Driveshaft/hub nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 200
Tie-rod end balljoint nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 25
Brake caliper mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 39
Front strut lower clamp bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Driveshaft inboard boot retainer bolts . . . . . . . . . . . . . . . . . . . . . . . . . . 9 7
Crankshaft pulley nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 7
1•6 Engine – general
Part 1: General
1 Description
1The Uno may be powered by one of three
engines depending upon the particular model.
903 cc
2This is of four cylinder overhead valve type
with a light alloy cylinder head and a cast-iron
block and crankcase.
3A three bearing crankshaft is used and the
chain-driven camshaft runs in three steel
backed white metal bearings.
4The light alloy pistons are fitted with two
compression and one oil control ring. The
gudgeon pin is an interference fit in the small
end of the connecting rod.
5Lubrication is provided by an oil pump
within the sump pan and both the pump and
the distributor are driven from a gear on the
camshaft. Pressurised oil passes through acartridge type oil filter. An oil pressure relief
valve is incorporated in the oil pump. The
engine oil is independent of the transmission
lubricant.
1116 cc and 1301 cc
6These engines are of single overhead
camshaft type, the camshaft being driven by a
toothed belt.
7The difference in engine capacity is
achieved by increasing the cylinder bore on
the 1301 cc engine.
8The cylinder head is of light alloy while the
cylinder block and crankcase are of cast-iron
construction.
9A five bearing crankshaft is used and the
camshaft runs in a similar number of bearings,
but as these are in-line bored directly in the
camshaft carrier, no repair is possible.
10The pistons are of light alloy with two
compression and one oil control ring. The
gudgeon pin is an interference fit in the small
end of the connecting rod.
11An auxiliary shaft, driven by the timing belt
is used to drive the distributor, oil pump and
fuel pump.12The oil pump is located within the sump
pan and incorporates a pressure relief valve.
13Pressurised oil passes through a cartridge
type oil filter.
14The crankshaft main bearings are
supplied under pressure from drillings in the
crankcase from the main oil gallery whilst the
connecting rod big-end bearings are
lubricated from the main bearings by oil
forced through the crankshaft oilways. The
camshaft bearings are fed from a drilling from
the main oil gallery. The cams and tappets are
lubricated by oil mist from outlets in the
camshaft bearings.
15The cylinder walls, pistons and gudgeon
pins are lubricated by oil splashed up by the
crankshaft webs. An oil pressure warning light
is fitted to indicate when the pressure is too
low.
All engines
16The engine is mounted transversely with
the transmission at the front of the car.
17The engine oil is independent of the
transmission lubricant.

13Engage the timing chain with the teeth of
the crankshaft sprocket. Then locate the
camshaft sprocket within the upper loop of
the chain in such a way that when the
sprocket is pushed onto the camshaft, the
timing marks will be in alignment. Make sure
that the self-tensioning links are on the inside
of the chain against the cylinder block
(photos).
14Place the camshaft sprocket onto the
camshaft so that its positioning dowel
engages.
15Secure the camshaft sprocket by fitting
the special cam, that drives the fuel pump, on
its locating dowel. Fit the camshaft sprocket
retaining bolt (photo).
16Tighten the sprocket bolt to the specified
torque.
17If the timing cover oil seal showed signs of
leaking before engine overhaul the old seal
should be removed and a new one fitted.
18Using a screwdriver, carefully remove the
old oil seal, working from the rear of the cover.
Fit the new seal making sure it is inserted
squarely, and tap home with a hammer.
19Lubricate the oil seal with engine oil.
20With all traces of old gasket and jointing
compound removed from the timing cover
and cylinder block mating faces, smear a little
grease onto the timing cover mating face and
fit a new gasket in position.
21Fit the timing cover to the cylinder block
and finger tighten the securing bolts, and
spring washer. Ensure that the fuel pump
pushrod bush is in place in the cover.22Wipe the hub of the pulley and carefully
place into position on the crankshaft. It should
locate on the Woodruff key. It may be
necessary to adjust the position of the timing
cover slightly in order to centralise the oil seal
relative to the pulley hub.
23Tighten the timing cover securing bolts in
a diagonal and progressive manner.
24Tighten the crankshaft pulley nut to the
specified torque again holding the crankshaft
against rotation as previously described
(paragraph 2) this Section.
25Refit the fuel pump and alternator
drivebelt.
7 Cylinder head-
removal and refitting
3
1For safety reasons, disconnect the battery
negative lead.
2Refer to Chapter 2 and drain the cooling
system.
3Refer to Chapter 3 and remove the
carburettor, air cleaner and spacer block.
4Undo and remove the five nuts and
washers securing the exhaust manifold and
hot air ducting to the cylinder head.
5Detach the cable from the temperature
indicator sender unit.
6Refer to Chapter 4 and disconnect the
distributor LT lead and the coil HT lead.
7Refer to Chapter 2 and remove the
thermostat housing from the cylinder head.
8Disconnect the coolant hoses from the
cylinder head.
9Note the electrical connections to the rear
of the alternator and disconnect them.
10Disconnect the mounting and adjuster link
bolts and remove the alternator from the
engine.
11Unscrew the four nuts securing the rocker
cover to the top of the cylinder head and lift
away the spring washers and metal packing
pieces. Remove the rocker cover and cork
gasket.
12Unscrew the four rocker pedestal
securing nuts in a progressive manner. Lift
away the four nuts and spring washers andease the valve rocker assembly from the
cylinder head studs.
13Remove the pushrods, keeping them in
the relative order in which they were removed.
The easiest way to do this is to push them
through a sheet of thick paper or thin card in
the correct sequence.
14Unscrew the cylinder head securing bolts
half a turn at a time in the reverse order to that
shown in Fig. 1.7; don’t forget the one within
the inlet manifold. When all the bolts are no
longer under tension they may be unscrewed
from the cylinder head one at a time. This will
also release a section of the cooling system
pipe secured by two of the bolts. All the bolts
have washers.
15The cylinder head may now be lifted off. If
the head is jammed, try to rock it to break the
seal. Under no circumstances try to prise it
apart from the cylinder block with a
screwdriver or cold chisel as damage may be
done to the faces of the head or block. If this
or the Hint, fail to work, strike the head
sharply with a plastic headed hammer, or with
a wooden hammer, or with a metal hammer
with an interposed piece of wood to cushion
the blows. Under no circumstances hit the
head directly with a metal hammer as this may
cause the casting to fracture. Several sharp
taps with the hammer, at the same time
pulling upwards, should free the head. Lift the
head off and place on one side.
16The cylinder head may now be de-
carbonised or dismantled, refer to Section 17.
Refitting
17After checking that both the cylinder block
and cylinder head mating surfaces are
perfectly clean, generously lubricate each
cylinder with engine oil.
18Always use a new cylinder head gasket as
the old gasket will be compressed and not
capable of giving a good seal.
1•10 903 cc engine
6.15 Fitting fuel pump drive cam and
sprocket bolt
6.13C Self-tensioning links on inside of
chain6.13B Timing mark alignment6.13A Fitting the sprockets and timing
chain
If the head will not readily
free, turn the crankshaft.
The compression generated
in the cylinders will often
break the gasket joint