MG MGB User Manual

Fa
THE OVERD RIVE
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H
t
x
“s
I_——
A92
93
Fig.
Fa.7
Align the
operating lever
to
check the adjustment
of the
operating
plunger
A
new
plunger
must
be
■tted
with
a
new
solenoid. It will be
necessary
to
check the
setting
for
correct
valve
operation
after
fitment.
Section
Fa.8
OPERATING
VALVE
Access
may
be
gained
to
the operating
valve
after
removing
the
gear
selector
remote
control
assembly
from
inside the
car
(see
Section
Fa.9).
Having
gained
access,
unscrew
the
plug and
remove
the
spring
and
plunger.
The
ball valve
will then be
seen
inside
the valve
chamber. The
ball
should be
lifted
3712
in.
(.8
mm.)
off
its
seat
when
the solenoid
is
operated.
If the
ball does
not
lift, the
fault lies
in
the
control
mechanism
(see
Section
Fa.7).
Remove
the ball
with
a
magnet
and
pull
out
the
valve,
using
a
piece
of
s
in.
(3.175
mm.)
dia. wire,
taking
care
not to
damage
the
seating
at
the
top
of the
valve. Near the bottom
of the
valve will be
seen a
small
hole breaking
through the
centre
drilling;
this
is
the
jet
for
restricting
the
exhaust
of
oil
from
the
operating
cylinders.
Check
the bore
of
the
operating
valve
with
a
%
in.
(3.175
mm.)
diameter
drill and
blow
out
the
jet.
If the ball
valve
is
not
seated
correctly the
ball
should
be
tapped sharply
onto
its
seat
in
the
casing,
using
a
soft-metal
drift.
V
If the
unit
fails
to
operate
and
the ball
valve
is
seating
and
lifting
correctly
check that
the
pump
is
functioning,
as
follows.
Jack
up
the
rear
wheels,
then
with
the
engine
idling and
the
valve plug
removed
engage
top
gear.
Watch for oil being
pumped
into
the valve
chamber.
If
none appears,
then
the
pump
is
not
functioning.
Possible
causes
of
trouble
are:
(1) Failure
of the
non-return
valve
due
to
foreign
matter
on
the
seat
or
to
a
broken
valve
spring,
and
(2) Breakage
of the spring
holding
the
pump
;_
plunger
in
contact
with the
cam.
j
Fa.8
Testing
oil
pressure
Remove
the
operating
valve
plug,
■t
an
adaptor
(Service
tool 18G
251D)
in
its
place, and
connect
up a
pressure
gauge.
Jack
up
the
rear
wheels
and then
with the
engine
idling
engage
top
gear.
Operate
the overdrive
solenoid;
a
pressure
of
540
to
5601b./sq.
in.
(37.97
to
39.37
kg./crn.2)
should be recorded.
Section Fa.9
REMOVING AND
REPLACING
To
dismantle
the
unit
further
than
already
described
necessitates
the
removal of the
unit
from
the
car.
It
is
not
possible
to
lift
out
the overdrive alone
from
the
car;
the
engine,
gearbox, and overdrive
must
be
removed
complete.
Removing
1.
Prepare the
engine
for removal from the
car as
detailed
in
Section A,
and
take the weight
of the
engine.
2.
Remove
the
retainer
and pull the
gear
lever
grormnet
clear of
the
remote
control
cover.
Release the
circlip
and
withdraw the
gear
lever
from
its
housing.
3.
Withdraw the four
screws
securing
the speaker
panel
and
remove
the panel.
Pull back the
tunnel
carpet
and
remove
the gearbox
remote
control
cover.
4.
Pull
the
solenoid
wire
from the
snap
connector
and
disconnect
the
gear
switch
wires.
5.
Drain the
oil from the gearbox
and overdrive.
6. Disconnect
and
remove
the propeller
shaft
as
detailed
in
Section
G, and
disconnect
the speedometer
pinion
drive.
7.
Disconnect
the clutch slave
cylinder
push-rod
from
the
clutch withdrawal lever
and
the slave
cylinder
from the
clutch housing. Tie
the cylinder
clear
of the
gearbox.
8.
Remove
the
screws
securing
the
rear
cross-member
to
the
body and lower
the
engine
and gearbox
until the
gearbox
rests
on
the fixed body
cross-member.
9.
Release
the
engine
stay-rod
bracket from the
rear
cross-member
and
remove
the four
nuts
and
washers
securing
the gearbox
rear
rubber mountings
to
the
cross-member.
Withdraw
the
rear
cross-member
from
the
body.
10.
Ease the
assembly
forward
until
it is
clear
of the
■xed
body
cross-member
and
then tilt the
assembly
and lift
it
from
the
car.
Replacement
is
a
reversal
of the
removal
sequence.
After
refitting the
unit
re■ll
with fresh oil.
Section
Fa.10
DISMANTLING AND
REASSEMBLING
Dismantling
Remove
the
remote
control assembly
after withdrawing
the
six
bolts and
spring
washers
securing
the control
to
the
MGB. Issue3.
65891

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English