MG MGB User Manual

THE OVERDRIVE
Fa
5.
Insuf■cient hydraulic
pressure
due
to
sticking
or
worn
relief
valve.
6. Damaged
gears,
hearings,
or
moving
parts
within the
unit requiring
removal
and
inspection
of
the
assembly.
Overdrive does
not
release
(NOTE—Do
not
attempt to
reverse
the
car or
damage
may
be caused within the
overdrive
unit.)
Fault
in
electrical
control
system.
Blocked
restrictor jet
in operating
valve.
Solenoid
operating
lever
adjustment.
Sticking
clutch.
Damaged
parts
within the
unit necessitating removal
and
inspection
of
the
assembly.
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Clutch slip
in overdrive
As 1, 3,
4, and
5
under
‘Overdrive does
not
engage’.
Clutch slip
in
reverse
or
free-wheel
condition
on
overrun
1.
Solenoid
operating
lever
out
of
adjustment.
2.
Partially
blocked
restrictor jet
in operating
valve.
3. Worn
clutch
linings.
Section F 3.5
PUMP
NON-RETURN
VALVE
Access
to
the
pump
non-return
valve
is gained
through
the
centre
cap
in
the
bottom of the
main casing
(see [2],
Fig,
Fa.6).
Removing
1.
Remove
the
engine
stay
rod
from
the
gearbox adaptor
and the
stay
rod bracket from
the
rear
cross-member.
2.
Remove the drain
plugs
and drain off the
oil.
3.
Unclip the
locking
wire.
Unscrew the
valve
cap
and
take
out
the
spring and
ball
and
unscrew
the
non-return
valve
body from the
pump
body.
Clean the
components
and
examine
the
seating
for
pits,,etc.
If the
ball valve
is
not
seating
correctly the
ball should
be
tapped
sharply
onto
its
seat
in
the
non-return
valve
body,
using
a
soft-metal
drift.
Fig.
Fa.6
Bottom view
of
overdrive unit
3.
Relief
valve plug.
1.
Drain plug.
2. Non—returnvalve plug.
MGB.
Issue
3. 60230
Reassembly
is
the
reverse
of
the above
sequence.
Position
the
ball
on
the
spring
with petroleum
jelly. Ensure
that the
copper
washer
between the
valve
cap
and
main
casing is
■tted
correctly
over
the
step
on
the
cap.
NOTE—The valve body
must
be
removed
from
the
pump
body
to reseat
the
ball valve,
otherwise
damage
may
be
caused
to
the
pump.
Section
Fa.6
RELIEF VALVE
Access
to
the relief
valve
is
gained through
the
right-hand
cap
in
the bottom
of the
main casing
(see
[3],
Fig.
Fa.6).
Removing
1.
Remove the
engine
stay
rod
from
the
gearbox adaptor
and the
stay
rod bracket from
the
rear
cross-member.
2. Remove the
drain
plugs and drain off
the oil.
3.
Unclip the
locking
wire.
Unscrew the
valve
cap
and
remove
the
spring
and
piston.
4. Remove the relief
valve
body with circlip
pliers, taking
care
not to
damage the
piston
bore.
Reassembly
is
the
reverse
of the
above
sequence.
Ensure
that the
copper
washer
between the
cap
and
main
casing is
■tted
correctly
over
the
step
on
the
cap.
Section
Fa.7
HYDRAULIC
LEVER
SETTING
The
setting
of
the
operating
lever
can
be checked
by
means
of
a
hole
in
the
lever
accessible from
under
the
car
after
removal of the
cover-plate
on
the
right-hand
side of
the
unit.
The
controls
are
set
correctly when
a
it;
in.
(4.76 mm.)
diameter
rod
can
be passed through
the hole
in
the lever
into
the
hole
in
the
casing
with
the solenoid
energized,
i.e.
with the
ignition switched
on,
top
gear
engaged, and the
fascia
switch
in
the
‘Overdrive’
position.
If the
solenoid
operates
but does
not
move
the
setting
lever
far
enough
to
allow the
rod
to
be
inserted,
the solenoid
plunger
must
be adjusted
as
follows.
Screw
the
self-locking
nut
on
the
plunger
in
or
out,
with
the plunger
pushed
into
the solenoid
as
far
as
it
will
go.
The
plunger
must
be held
against
rotation
with
a
spanner
on
two
■ats
on
the spindle. The
operating
lever fork
should
just
contact
the
nut
with the
1% in.
(4.74
mm.)
rod
in
position.
Operate
the overdrive
several
times and check
that the
setting
rod
can
be inserted
and
that
the solenoid
current
does
not
exceed
2
amperes.
If the
current
is maintained
at
17
amperes
(approx.),
it
indicates that
the solenoid
plunger
is
not
moving
far
enough
to
switch from
the
operating
to
the
holding coil; the plunger
must
therefore
be
readjusted.
Fa.7

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English