MG MGB User Manual

THE CLUTCH
E
GENERAL
DESCRIPTION
The
clutch
mechanism
is
hydraulically operated
and
consists
of
a
driven
plate,
a
pressure
plate, and
a
diaphragm
spring
and
cover
assembly, The
cover
is
bolted
to
the
■ywheel
and encloses
the driven
plate,
pressure
plate, and
diaphragm
spring.
The
hydraulic
system
comprises
a
master
cylinder
coupled
to
a
slave
cylinder
which
operates
the
clutch release
mechanism.
Section
E]
CLUTCH
ASSEMBLY
The
driven
plate comprises
a
splined hub
connected
to
a
■exible steel
plate
by
a
spring
mounting.
The annular
friction
facings
are
riveted
to
the plate
and
damper springs
are
assembled
around the
hub
to
absorb
power
shocks and
torsional vibration.
The
diaphragm spring is
interposed between
two
annular
rings
which
provide
fulcrum
points
for the
diaphragm when
it is
■exed. The
rings
and the
diaphragm
are
located
and
secured
to
the
cover
by
nine
equally
spaced
rivets.
Three
clips
that
engage
the
outer
edge
of the diaphragm
are
bolted
to
the
pressure
plate.
The
bolts
pass
through three
straps
which
are
riveted
to
the inside
of the
cover;
the
straps
prevent
the diaphragm
and
the
pressure
plate
from
rotating
in
relation
to
the
cover.
The
release
plate
is
secured
directly
to
the
diaphragm and
is
an
integral
part
of the
clutch
cover
assembly.
On early
cars
the release
plate
is
retained
with
a
circlip
and
can
be
removed when
the
circlip
is
released.
The release
bearing is
graphite
and
is
mounted in
a cup
which
■ts
into
the
fork
of the
clutch
withdrawal lever.
The
cup
is
held
in
position
by
two
spring
retainers.
Removing
Remove
the
engine
as
described
in
Section
A.2l.
Loosen
each
of the
bolts
securing
the
clutch assembly
to
the
■ywheel
by
slackening
them
a
turn
at
a
time
until
spring
pressure
is
released.
The
clutch
cover
can now
be
disengaged
from
the
dowels
on
the
■ywheel
and the
assembly
removed.
Dismantling
On
earlier
cars
remove
the
circlip
securing
the release
plate
to
the
diaphragm
and
lift the
plate from
the diaphragm.
Unscrew
the three
screws
securing
the
clips
to
the
pressure
plate,
a
turn
at
a
time,
until
the
diaphragm
contacts
the
cover.
Remove
the
screws,
clips, and
washers
and the
pressure
plate.
Rotate
the release
bearing spring
retainers
through
90°
and
withdraw
the bearing
from the
withdrawal lever
fork.
MGB. Issue
4.
15676
Assembling
Assembly
is
a
reversal of the
dismantling
sequence,
but
ensure
that the release
bearing
retainers
are
correctly
located.
Replacing
Position
the driven plate
assembly
on
the flywheel with the
large
end
of the hub
away
from
the ■ywheel.
Centralize
the
plate
by
using
Service
tool 18G 680,
which
■ts
the splined
hub of the
driven plate
and the
pivot
bearing
in
the ■ywheel. As
an
alternative,
a
spare
first
motion
shaft
can
be used.
Locate
the
cover
assembly
on
the ■ywheel
dowels and
secure
it
with the bolts;
tighten the
bolts down
a
turn at
a
time
by
diametrical selection.
Do
not
remove
the
centralizer
until all bolts
are
securely tightened.
Remove
the clutch
centralizer
and
refit the
engine.
The
weight
of
the gearbox
must
be supported
during
refitting
in
order
to
avoid
strain
on
the
■rst
motion
shaft and
distortion
or
displacement
of
the
release plate and
straps,
or
driven
plate
assembly.
Fig.
E.1
A
section
through
the clutch
1.
Cover.
7.
Releaseplate.
2.
Strap
bolt.
8. Strapgrelease
3.
Washer—tab.
plate/cover.
4.
Clip.
9.
Diaphragm
spring.
5.
Strapidiaphragm
cover.
10.
Pressureplate.
6.
Releasebearing.
11.
Driven plate.
E.3

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English