1990 BMW 5 SERIES alternator

REF•18Automotive chemicals and lubricants
A number of automotive chemicals and
lubricants are available for use during vehicle
maintenance and repair. They include a wide
variety of products ranging from cleaning
solvents and degreasers to lubricants and
protective sprays for rubber, plastic and
vinyl.
Cleaners
Carburettor cleaner and choke cleaner
is a strong solvent for gum, varnish and
carbon. Most carburettor cleaners leave a
dry-type lubricant film which will not harden or
gum up. Because of this film, it is not
recommended for use on electrical
components.
Brake system cleaneris used to remove
grease and brake fluid from the brake system,
where clean surfaces are absolutely
necessary. It leaves no residue, and often
eliminates brake squeal caused by
contaminants.
Electrical cleaner removes oxidation,
corrosion and carbon deposits from electrical
contacts, restoring full current flow. It can also
be used to clean spark plugs, carburettor jets,
voltage regulators and other parts where an
oil-free surface is desired.
Moisture dispersantsremove water and
moisture from electrical components such as
alternators, voltage regulators, electrical
connectors and fuse blocks. They are non-
conductive and non-corrosive.
Degreasersare heavy-duty solvents used
to remove grease from the outside of the
engine and from chassis components. They
can be sprayed or brushed on, and are usually
rinsed off with water.
Lubricants
Engine oilis the lubricant formulated for
use in engines. It normally contains a wide
variety of additives to prevent corrosion and
reduce foaming and wear. Engine oil comes in
various weights (viscosity ratings) from 5 to
60. The recommended weight of the oil
depends on the season, temperature and the
demands on the engine. Light oil is used in
cold climates and under light load conditions.
Heavy oil is used in hot climates, and where
high loads are encountered. Multi-viscosity
(multigrade) oils are designed to have
characteristics of both light and heavy oils,
and are available in a number of weights from
5W-20 to 20W-50.
Gear oilis designed to be used in
differentials, manual transmissions and other
areas where high-temperature lubrication is
required.
Chassis and wheel bearing greaseis a
heavy grease used where increased loads and
friction are encountered, such as for wheel
bearings, balljoints, tie-rod ends and universal
joints.High-temperature wheel bearing grease
is designed to withstand the extreme
temperatures encountered by wheel bearings
in disc brake-equipped vehicles. It usually
contains molybdenum disulphide (moly),
which is a dry-type lubricant.
White greaseis a heavy grease for metal-
to-metal applications where water is a
problem. White grease stays soft at both low
and high temperatures, and will not wash off
or dilute in the presence of water.
Assembly lubeis a special extreme-
pressure lubricant, usually containing moly,
used to lubricate high-load parts (such as
main and rod bearings and cam lobes) for
initial start-up of a new engine. The assembly
lube lubricates the parts without being
squeezed out or washed away until the engine
oiling system begins to function.
Silicone lubricants are used to protect
rubber, plastic, vinyl and nylon parts.
Graphite lubricantsare used where oils
cannot be used due to contamination
problems, such as in locks. The dry graphite
will lubricate metal parts while remaining
uncontaminated by dirt, water, oil or acids. It
is electrically conductive, and will not foul
electrical contacts in locks such as the
ignition switch.
Penetrating oilsloosen and lubricate
frozen, rusted and corroded fasteners and
prevent future rusting or freezing.
Heat-sink greaseis a special electrically
non-conductive grease that is used for
mounting electronic ignition modules where it
is essential that heat is transferred away from
the module.
Sealants
RTV sealantis one of the most widely-
used gasket compounds. Made from silicone,
RTV is air-curing; it seals, bonds, waterproofs,
fills surface irregularities, remains flexible,
doesn’t shrink, is relatively easy to remove,
and is used as a supplementary sealer with
almost all low- and medium-temperature
gaskets.
Anaerobic sealantis much like RTV in that
it can be used either to seal gaskets or to form
gaskets by itself. It remains flexible, is solvent-
resistant, and fills surface imperfections. The
difference between an anaerobic sealant and
an RTV-type sealant is in the curing. RTV
cures when exposed to air, while an anaerobic
sealant cures only in the absence of air. This
means that an anaerobic sealant cures only
after the assembly of parts, sealing them
together.
Thread and pipe sealant is used for
sealing hydraulic and pneumatic fittings and
vacuum lines. It is usually made from a Teflon
compound, and comes in a spray, a paint-on
liquid and as a wrap-around tape.
Chemicals
Anti-seize compoundprevents seizing,
chafing, cold welding, rust and corrosion in
fasteners. High-temperature anti-seize,
usually made with copper and graphite
lubricants, is used for exhaust system and
exhaust manifold bolts.
Anaerobic locking compoundsare used
to keep fasteners from vibrating or working
loose, and cure only after installation, in the
absence of air. Medium-strength locking
compound is used for small nuts, bolts and
screws that may be removed later. High-
strength locking compound is for large nuts,
bolts and studs which aren’t removed on a
regular basis.
Oil additivesrange from viscosity index
improvers to chemical treatments that claim
to reduce internal engine friction. It should be
noted that most oil manufacturers caution
against using additives with their oils.
Fuel additivesperform several functions,
depending on their chemical make-up. They
usually contain solvents that help dissolve
gum and varnish that build up on carburettor,
fuel injection and intake parts. They also serve
to break down carbon deposits that form on
the inside surfaces of the combustion
chambers. Some additives contain upper
cylinder lubricants for valves and piston rings,
and others contain chemicals to remove
condensation from the fuel tank.
Miscellaneous
Brake fluidis specially-formulated
hydraulic fluid that can withstand the heat and
pressure encountered in brake systems. It is
poisonous and inflammable. Care must be
taken so this fluid does not come in contact
with painted surfaces or plastics. An opened
container should always be resealed, to
prevent contamination by water or dirt. Brake
fluid absorbs moisture from the air, if left in an
unsealed container.
Weatherstrip adhesiveis used to bond
weatherstripping around doors, windows and
boot lids. It is sometimes used to attach trim
pieces.
Undersealis a petroleum-based, tar-like
substance that is designed to protect metal
surfaces on the underside of the vehicle from
corrosion. It also acts as a sound-deadening
agent by insulating the bottom of the vehicle.
Waxes and polishesare used to help
protect painted and plated surfaces from the
weather. Different types of paint may require
the use of different types of wax and polish.
Some polishes utilise a chemical or abrasive
cleaner to help remove the top layer of
oxidised (dull) paint on older vehicles. In
recent years, many non-wax polishes
containing a wide variety of chemicals such as
polymers and silicones have been introduced.
These non-wax polishes are usually easier to
apply, and last longer than conventional
waxes and polishes.

REF•20Glossary of Technical Terms
A
ABS (Anti-lock brake system)A system,
usually electronically controlled, that senses
incipient wheel lockup during braking and
relieves hydraulic pressure at wheels that are
about to skid.
Air bag An inflatable bag hidden in the
steering wheel (driver’s side) or the dash or
glovebox (passenger side). In a head-on
collision, the bags inflate, preventing the
driver and front passenger from being thrown
forward into the steering wheel or windscreen.
Air cleanerA metal or plastic housing,
containing a filter element, which removes
dust and dirt from the air being drawn into the
engine.
Air filter elementThe actual filter in an air
cleaner system, usually manufactured from
pleated paper and requiring renewal at regular
intervals.
Allen keyA hexagonal wrench which fits into
a recessed hexagonal hole.
Alligator clipA long-nosed spring-loaded
metal clip with meshing teeth. Used to make
temporary electrical connections.
AlternatorA component in the electrical
system which converts mechanical energy
from a drivebelt into electrical energy to
charge the battery and to operate the starting
system, ignition system and electrical
accessories.
Ampere (amp)A unit of measurement for the
flow of electric current. One amp is the
amount of current produced by one volt
acting through a resistance of one ohm.
Anaerobic sealerA substance used to
prevent bolts and screws from loosening.
Anaerobic means that it does not require
oxygen for activation. The Loctite brand is
widely used.
AntifreezeA substance (usually ethylene
glycol) mixed with water, and added to a
vehicle’s cooling system, to prevent freezing
of the coolant in winter. Antifreeze also
contains chemicals to inhibit corrosion and
the formation of rust and other deposits thatwould tend to clog the radiator and coolant
passages and reduce cooling efficiency.
Anti-seize compoundA coating that
reduces the risk of seizing on fasteners that
are subjected to high temperatures, such as
exhaust manifold bolts and nuts.
AsbestosA natural fibrous mineral with great
heat resistance, commonly used in the
composition of brake friction materials.
Asbestos is a health hazard and the dust
created by brake systems should never be
inhaled or ingested.
AxleA shaft on which a wheel revolves, or
which revolves with a wheel. Also, a solid
beam that connects the two wheels at one
end of the vehicle. An axle which also
transmits power to the wheels is known as a
live axle.
AxleshaftA single rotating shaft, on either
side of the differential, which delivers power
from the final drive assembly to the drive
wheels. Also called a driveshaft or a halfshaft.
BBall bearingAn anti-friction bearing
consisting of a hardened inner and outer race
with hardened steel balls between two races.BearingThe curved surface on a shaft or in a
bore, or the part assembled into either, that
permits relative motion between them with
minimum wear and friction.
Big-end bearingThe bearing in the end of
the connecting rod that’s attached to the
crankshaft.
Bleed nippleA valve on a brake wheel
cylinder, caliper or other hydraulic component
that is opened to purge the hydraulic system
of air. Also called a bleed screw.
Brake bleedingProcedure for removing air
from lines of a hydraulic brake system.
Brake discThe component of a disc brake
that rotates with the wheels.
Brake drumThe component of a drum brake
that rotates with the wheels.
Brake liningsThe friction material which
contacts the brake disc or drum to retard the
vehicle’s speed. The linings are bonded or
riveted to the brake pads or shoes.
Brake padsThe replaceable friction pads
that pinch the brake disc when the brakes are
applied. Brake pads consist of a friction
material bonded or riveted to a rigid backing
plate.
Brake shoeThe crescent-shaped carrier to
which the brake linings are mounted and
which forces the lining against the rotating
drum during braking.
Braking systemsFor more information on
braking systems, consult the Haynes
Automotive Brake Manual.
Breaker barA long socket wrench handle
providing greater leverage.
BulkheadThe insulated partition between
the engine and the passenger compartment.
CCaliperThe non-rotating part of a disc-brake
assembly that straddles the disc and carries
the brake pads. The caliper also contains the
hydraulic components that cause the pads to
pinch the disc when the brakes are applied. A
caliper is also a measuring tool that can be set
to measure inside or outside dimensions of an
object.
Brake bleeding
Bearing
Axle assembly
Anti-seize compound
Alternator (exploded view)
Air filter

REF•21
REF
Glossary of Technical Terms
CamshaftA rotating shaft on which a series
of cam lobes operate the valve mechanisms.
The camshaft may be driven by gears, by
sprockets and chain or by sprockets and a
belt.
CanisterA container in an evaporative
emission control system; contains activated
charcoal granules to trap vapours from the
fuel system.
CarburettorA device which mixes fuel with
air in the proper proportions to provide a
desired power output from a spark ignition
internal combustion engine.
CastellatedResembling the parapets along
the top of a castle wall. For example, a
castellated balljoint stud nut.
CastorIn wheel alignment, the backward or
forward tilt of the steering axis. Castor is
positive when the steering axis is inclined
rearward at the top.Catalytic converterA silencer-like device in
the exhaust system which converts certain
pollutants in the exhaust gases into less
harmful substances.
CirclipA ring-shaped clip used to prevent
endwise movement of cylindrical parts and
shafts. An internal circlip is installed in a
groove in a housing; an external circlip fits into
a groove on the outside of a cylindrical piece
such as a shaft.
ClearanceThe amount of space between
two parts. For example, between a piston and
a cylinder, between a bearing and a journal,
etc.
Coil springA spiral of elastic steel found in
various sizes throughout a vehicle, for
example as a springing medium in the
suspension and in the valve train.
CompressionReduction in volume, and
increase in pressure and temperature, of a
gas, caused by squeezing it into a smaller
space.
Compression ratioThe relationship between
cylinder volume when the piston is at top
dead centre and cylinder volume when the
piston is at bottom dead centre.
Constant velocity (CV) jointA type of
universal joint that cancels out vibrations
caused by driving power being transmitted
through an angle.
Core plugA disc or cup-shaped metal device
inserted in a hole in a casting through which
core was removed when the casting was
formed. Also known as a freeze plug or
expansion plug.
CrankcaseThe lower part of the engine
block in which the crankshaft rotates.
CrankshaftThe main rotating member, or
shaft, running the length of the crankcase,
with offset “throws” to which the connecting
rods are attached.Crocodile clipSee Alligator clip
DDiagnostic codeCode numbers obtained by
accessing the diagnostic mode of an engine
management computer. This code can be
used to determine the area in the system
where a malfunction may be located.
Disc brakeA brake design incorporating a
rotating disc onto which brake pads are
squeezed. The resulting friction converts the
energy of a moving vehicle into heat.
Double-overhead cam (DOHC)An engine
that uses two overhead camshafts, usually
one for the intake valves and one for the
exhaust valves.
Drivebelt(s)The belt(s) used to drive
accessories such as the alternator, water
pump, power steering pump, air conditioning
compressor, etc. off the crankshaft pulley.
DriveshaftAny shaft used to transmit
motion. Commonly used when referring to the
axleshafts on a front wheel drive vehicle.
Drum brakeA type of brake using a drum-
shaped metal cylinder attached to the inner
surface of the wheel. When the brake pedal is
pressed, curved brake shoes with friction
linings press against the inside of the drum to
slow or stop the vehicle.
Castellated nut
Catalytic converter
Crankshaft assembly
Carburettor
Canister
Drum brake assembly
Accessory drivebelts
Driveshaft

REF•23
REF
Glossary of Technical Terms
JJump startStarting the engine of a vehicle
with a discharged or weak battery by
attaching jump leads from the weak battery to
a charged or helper battery.
LLoad Sensing Proportioning Valve (LSPV)A
brake hydraulic system control valve that
works like a proportioning valve, but also
takes into consideration the amount of weight
carried by the rear axle.
LocknutA nut used to lock an adjustment
nut, or other threaded component, in place.
For example, a locknut is employed to keep
the adjusting nut on the rocker arm in
position.
LockwasherA form of washer designed to
prevent an attaching nut from working loose.
MMacPherson strutA type of front
suspension system devised by Earle
MacPherson at Ford of England. In its original
form, a simple lateral link with the anti-roll bar
creates the lower control arm. A long strut - an
integral coil spring and shock absorber - is
mounted between the body and the steering
knuckle. Many modern so-called MacPherson
strut systems use a conventional lower A-arm
and don’t rely on the anti-roll bar for location.
MultimeterAn electrical test instrument with
the capability to measure voltage, current and
resistance.
NNOxOxides of Nitrogen. A common toxic
pollutant emitted by petrol and diesel engines
at higher temperatures.
OOhmThe unit of electrical resistance. One
volt applied to a resistance of one ohm will
produce a current of one amp.
OhmmeterAn instrument for measuring
electrical resistance.
O-ringA type of sealing ring made of a
special rubber-like material; in use, the O-ring
is compressed into a groove to provide the
sealing action.Overhead cam (ohc) engineAn engine with
the camshaft(s) located on top of the cylinder
head(s).
Overhead valve (ohv) engineAn engine with
the valves located in the cylinder head, but
with the camshaft located in the engine block.
Oxygen sensorA device installed in the
engine exhaust manifold, which senses the
oxygen content in the exhaust and converts
this information into an electric current. Also
called a Lambda sensor.
PPhillips screwA type of screw head having a
cross instead of a slot for a corresponding
type of screwdriver.
PlastigageA thin strip of plastic thread,
available in different sizes, used for measuring
clearances. For example, a strip of Plastigage
is laid across a bearing journal. The parts are
assembled and dismantled; the width of the
crushed strip indicates the clearance between
journal and bearing.
Propeller shaftThe long hollow tube with
universal joints at both ends that carries
power from the transmission to the differential
on front-engined rear wheel drive vehicles.
Proportioning valveA hydraulic control
valve which limits the amount of pressure to
the rear brakes during panic stops to prevent
wheel lock-up.
RRack-and-pinion steeringA steering system
with a pinion gear on the end of the steering
shaft that mates with a rack (think of a geared
wheel opened up and laid flat). When the
steering wheel is turned, the pinion turns,
moving the rack to the left or right. This
movement is transmitted through the track
rods to the steering arms at the wheels.
RadiatorA liquid-to-air heat transfer device
designed to reduce the temperature of the
coolant in an internal combustion engine
cooling system.
RefrigerantAny substance used as a heat
transfer agent in an air-conditioning system.
R-12 has been the principle refrigerant for
many years; recently, however, manufacturers
have begun using R-134a, a non-CFC
substance that is considered less harmful tothe ozone in the upper atmosphere.
Rocker armA lever arm that rocks on a shaft
or pivots on a stud. In an overhead valve
engine, the rocker arm converts the upward
movement of the pushrod into a downward
movement to open a valve.
RotorIn a distributor, the rotating device
inside the cap that connects the centre
electrode and the outer terminals as it turns,
distributing the high voltage from the coil
secondary winding to the proper spark plug.
Also, that part of an alternator which rotates
inside the stator. Also, the rotating assembly
of a turbocharger, including the compressor
wheel, shaft and turbine wheel.
RunoutThe amount of wobble (in-and-out
movement) of a gear or wheel as it’s rotated.
The amount a shaft rotates “out-of-true.” The
out-of-round condition of a rotating part.
SSealantA liquid or paste used to prevent
leakage at a joint. Sometimes used in
conjunction with a gasket.
Sealed beam lampAn older headlight design
which integrates the reflector, lens and
filaments into a hermetically-sealed one-piece
unit. When a filament burns out or the lens
cracks, the entire unit is simply replaced.
Serpentine drivebeltA single, long, wide
accessory drivebelt that’s used on some
newer vehicles to drive all the accessories,
instead of a series of smaller, shorter belts.
Serpentine drivebelts are usually tensioned by
an automatic tensioner.
ShimThin spacer, commonly used to adjust
the clearance or relative positions between
two parts. For example, shims inserted into or
under bucket tappets control valve
clearances. Clearance is adjusted by
changing the thickness of the shim.
Slide hammerA special puller that screws
into or hooks onto a component such as a
shaft or bearing; a heavy sliding handle on the
shaft bottoms against the end of the shaft to
knock the component free.
SprocketA tooth or projection on the
periphery of a wheel, shaped to engage with a
chain or drivebelt. Commonly used to refer to
the sprocket wheel itself.
Starter inhibitor switchOn vehicles with an
O-ring
Serpentine drivebelt
Plastigage

REF•25
REF
Index
Note: References throughout this index relate to Chapter•page number
A
ABS - 9•2
Accelerator cable - 4•9
Acknowledgements - 0•4
Aerial - 12•4
Air bags - 0•5
Air cleaner - 4•8
Air conditioning system - 3•2, 3•7, 3•8,
3•9, 3•10
Air filter - 1•20
Air gap - 5•7
Air intake system - 4•2, 4•14
Airflow meter - 4•15, 6•4
Alternator - 5•10
Anti-lock Braking system (ABS) - 9•2
Anti-roll bar - 10•4, 10•9
Anti-theft audio system - 0•7
Antifreeze - 1•3, 1-8, 3•2
Asbestos - 0•5
ATF - 1•3, 1•13, 1•23
Automatic choke - 4•13
Automatic transmission- 7B•1et seq
Automatic transmission fault finding -
7B•4, REF•13
Automatic transmission fluid - 1•3, 1•13,
1•23
B
Backfire - REF•11
Balljoints - 10•7
Battery - 0•5, 1•16, 5•2
Battery fault - REF•11
Big-end bearings - 2B•17, 2B•21
Bleeding brakes - 9•14
Bleeding clutch - 8•4
Bleeding power steering - 10•16Block - 2B•14, 2B•15
Blower motor - 3•7
Body corrosion - REF•4
Body electrical systems- 12•1et seq
Bodywork and fittings- 11•1et seq
Bonnet - 11•4
Boot lid - 11•6
Boots - 8•9, 10•13
Brake fluid - 1•3, 1•9
Brake lines and hoses - 1•22, 9•13
Braking system- 1•22, 9•1et seq,REF•1,
REF•2, REF•3
Braking system fault finding - REF•14
Bulbs - 12•6
Bumpers - 11•6
Burning - 0•5
C
Cables - 4•9, 5•2, 7B•3, 9•12
Calipers - 9•4
Cam followers - 2B•11
Camshaft - 2A•12, 2B•11
Carburettor - 4•10, 4•11
Carpets - 11•2
Catalytic converter - 4•20, 6•6
Central locking - 12•8
Charging - 1•17, 5•9
Chemicals - REF•18
Choke - 4•13
Clutch and driveline- 8•1et seq
Clutch fault finding - REF•12
Clutch fluid - 1•3, 1•9
CO level adjustment - 1•15, REF•4
Coil - 5•5
Coil springs - 10•7, 10•9
Cold start injectors - 4•17, 4•18
Compression check - 2B•4Compressor - 3•8
Condenser - 3•9
Connecting rods -2B•12, 2B•16, 2B•21
Constant velocity (CV) joint - 8•2, 8•8, 8•9
Continuity check - 12•2
Control arm - 10•4, 10•5
Conversion factors - REF•17
Coolant - 1•3, 1•8
Coolant pump - 3•5
Coolant temperature sender unit - 3•6
Coolant temperature sensor - 6•2
Cooling fan - 3•4
Cooling, heating and air conditioning
systems- 1•21, 1•24, 3•1et seq
Cooling system fault finding - REF•12
Crankshaft - 2A•12, 2A•13, 2A•19, 2B•13,
2B•17, 2B•19, 2B•20
Cruise control - 12•3, 12•8
Crushing - 0•5
Cushion - 11•9
CV joints - 8•2, 8•8, 8•9
Cylinder head - 2A•13, 2B•7, 2B•10, 2B•12
Cylinder honing - 2B•15
D
Dents in bodywork - 11•2
Differential (final drive) - 8•2, 8•10, 8•11
Differential oil -1•3, 1•19, 1•26
Direction indicators - 12•2, 12•3
Discs - 1•22, 9•5
Distributor - 1•18, 5•4
Door - 11•6, 11•8, REF•2
Drivebelts - 1•14
Driveplate - 2A•18
Driveshafts - 1•22, 8•2, 8•9
Drums - 1•23