40 - 2
Removal and Replacement
Disconnect cables and remove battery. Remove cables from
main starter terminal and solenoid terminal. Using special
tool 825/00410 (and adapter 825/99833 if required) unscrew
three securing nuts and remove starter motor.
Replace by reversing the removal sequence.
Dismantling
Note:
Dismantle only to item
34
unless the field windings are
to be renewed. Test the windings electrically before
removing them from the motor yoke
15
.
Using a slotted steel tube, displace ring
23
to permit
withdrawal of ring
22
.
Allow brake shoes
28
to remain in the end plate
11
unless
requiring renewal.
Inspection
Renew brushes
14
and
14A
if their length is less than 8mm
(0.3in.).
Clean the commutator
A
. If individual copper bars are
burned or eroded the armature has broken windings and
must be renewed. Otherwise polish with fine grade glass
paper (not emery). Renew armature if commutator diameter
is 38mm (1.5in.) or less.
Check the field windings for open circuits by connecting a
multimeter set to measure resistance (see
Electrical Testing
Methods
) between the stud terminal
B
and each positive
brush
14A
in turn. A high or infinity reading indicates an
open circuit. Similarly, connect the meter between brushes
14A
and the motor yoke
15
. Any reading other than infinity
indicates a short circuit between the coils and the yoke.
Renew the coils as necessary, removing screws
36
with a
pole shoe screwdriver C50 (obtainable from Lucas dealers).
Check bronze bushes
32
and
34
for wear.
Assembly
Align crosspin
C
with the notches in the brake shoes
28
before assembling brush carrier and back plate to motor
yoke. Ensure that brushes
14A
are correctly located in the
insulated brush boxes.
Smear drive shaft splines and operating collar bearing
surface with JCB MPL Grease before assembly. Assemble
operating fork
19
with curved face toward the armature.
Set the movement of drive pinion
24
by connecting a 6v
battery and switch as shown. Operate switch and check
dimension
D
. Adjust to 0.13-1.14mm (0.005-0.045in.) by
slackening locknut
17
and rotating eccentric pin
18
as
necessary. Re-tighten locknut.
Section C
9803/3280
Section C
40 - 2
Issue 1
Starter Motor
S02303A
D
