MG MGB User Manual

THE
ELECTRICAL SYSTEM
N
16.
Clean
any
burrs
from
the
gear
shaft and
withdraw the
gear,
taking
care
not to
lose
the dished
washer ■tted
under
it.
17.
Mark
the yoke
and gearbox
for
reassembly.
18.
Unscrew
the
two
■xing
bolts
from the yoke
and
remove
the
yoke
assembly
and
armature.
The yoke
must
be
kept clear
of
metallic particles
which will be
attracted
to
the
pole—piece.
19.
Remove
the
screws
securing
the brush
gear
and the
terminal end
switch
assembly, and
remove
both
assemblies.
Inspection
MOTOR AND
GEARBOX
ASSEMBLY
20.
Examine
the
brushes
for
excessive
wear.
If the
main
bushes
(diametrically
opposite)
are worn
to
Tl;
in
(4.8
mm.)
or
if the
narrow
section
of
the
third brush
is
worn
to
the
full Width
of the
brush the
brush
gear
assembly
must
be
renewed.
21.
Check
the
brush
Spring
pressure
with
a
push—type
gauge.
The
gauge
reading
should be 5
to
7
oz.
(140
to
200
gm.)
when the bottom
of the brush
is
level with
the bottom
of the slot
in
the
brush box.
The brush
gear
assembly
must
be
renewed
if the
springs
are
not
satisfactory.
22.
Test
the
armature
for
insulation and
open- or
short-circuits.
Renew
the
armature
if faulty.
23.
Examine
the
gear
wheel for damage
or
excessive
wear.
Renew
if
necessary.
Reassembling
MOTOR
AND
GEARBOX
ASSEMBLY
24.
Reverse
the dismantling
procedure
in
12
to
19, noting
the
following
points:
3.
Use
Ragosine
Histate
Grease
to
lubricate
the
gear
wheel
teeth and
cam.
armature
shaft
worm
gear,
connecting
rod
and
pin,
cross-head slide,
cable
rack, and
wheelbase
gear
wheels.
b.
Use
Shell Turbo 41
oil
to
lubricate
the bearing
bushes,
armature
shaft bearing
journals
(sparingly),
gear
wheel
shaft and
crankpin,
felt
washer
in
the
yoke bearing
(thoroughly
soak),
and the
wheelbox
spindles.
c.
Tighten the
yoke
fixing bolts
to
a
torque
■gure
of
20
lb.
in.
(.23
kg.
m.).
d.
If
a
replacement
armature
is
being
fitted, slacken
the thrust
screw
to
provide end-■oat
for
fitting
the
yoke.
e
Fit
the thrust disc
inside
the yoke bearing
with
its
concave
side
towards the
end face
of the
bearing.
f Fit
the
dished washer
beneath
the
gear
wheel
with
its
concave
side
towards the
gear
wheel.
g.
When
fitting the
connecting
rod
to
the crankpin
ensure
that the
larger
of the
two
■at washers
is
fitted under the connecting
rod with the
smaller
one on
top
beneath the circlip.
MGB.
Issue3.
25729
h.
With
the thrust
screw
fully tightened
against
the
gearbox
casing,
an
end-■oat of
.004
to
.008
in.
(.l
to
.21
mm.)
should
exist
on
the
armature.
Adjustment of the
armature
end-■oat
can
be
achieved
by adjustment
of the
thrust
screw.
DOGOI
Fig. N31
The
armature
end-■oat adjusting
screw
Refitting
WHEELBOXES
25.
Reverse
the
removing
procedure
in
8
to
11.
MOTOR
AND
GEARBOX
ASSEMBLY
26. Reverse
the
removing
procedure
in 1
to
7
ensuring
that
the
inner
cable
engages
correctly
with
the
wheelbox
gear
teeth.
Section
N.28
STARTER
(Lucas
Type
M418G
Pre-engaged)
Removing
1.
Disconnect
the
battery.
2
Remove
the distributor Section B5.
3.
Remove
the
starter
top
securing
bolt.
4 Disconnect
the
wiring
from the
starter
terminals.
5. Remove
the
starter
lower
securing
bolt and
remove
the
starter.
Dismantling
,6.
Disconnect
the
lower
solenoid
terminal marked ‘STA’.
7. Remove
the solenoid
unit
securing
nuts.
8.
Withdraw the solenoid
from the drive end bracket,
carefully disengaging
the solenoid plunger
from the
drive
engagement
lever.
9. Remove
the
cover
band and
lift the brushes from their
holders.
10. Unscrew
the
two
through-bolts from the
commutator
end bracket.
11.
Slacken
the drive
engagement
lever
pivot pin securing
nut;
unscrew
and withdraw
the
pin.
N33

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English