Lexus RX300 (MCU15). Service manual — part 506

ST09C–02

P10584

Ohmmeter

Continuity

P10585

Ohmmeter

No Continuity

P10586

P10587

ST0040

ST–8

–

STARTING

STARTER

LEXUS RX300 (RM785E)

INSPECTION

1.

INSPECT ARMATURE COIL

(a)

Check the commutator for open circuit.
Using an ohmmeter, check that there is continuity be-
tween the segments of the commutator.

If there is no continuity between any segment, replace the ar-
mature.

(b)

Check the commutator for ground.
Using an ohmmeter, check that there is no continuity be-
tween the commutator and armature coil core.

If there is continuity, replace the armature.
2.

INSPECT COMMUTATOR

(a)

Check the commutator for the dirty and burnt surfaces.

If the surface is dirty or burnt, correct it with sandpaper (No.400)
or on a lathe.

(b)

Check for the commutator circle runout.
(1)

Place the commutator on V–blocks.

(2)

Using a dial gauge, measure the circle runout.

Maximum circle runout:
0.05 mm (0.0020 in.)

If the circle runout is greater than maximum, correct it on a lathe.

(c)

Using vernier calipers, measure the commutator diame-
ter.
Standard diameter:
30.0 mm (1.181 in.)
Minimum diameter:
29.0 mm (1.142 in.)

If the diameter is less than minimum, replace the armature.

(d)

Check that the undercut depth is clean and free of foreign
materials. Smooth out the edge.
Standard undercut depth:
0.6 mm (0.024 in.)
Minimum undercut depth:
0.2 mm (0.008 in.)

If the undercut depth is less than minimum, correct it with a
hacksaw blade.

P10588

Ohmmeter

Continuity

P10589

Ohmmeter

No Continuity

Z10079

Brush Holder Side

Field Flame Side

Length

Length

ST0019

–

STARTING

STARTER

ST–9

LEXUS RX300 (RM785E)

3.

INSPECT FIELD COIL

(a)

Check the field coil for open circuit.
Using an ohmmeter, check that there is continuity be-
tween the lead wire and field coil brush lead.

If there is no continuity, replace the field frame.

(b)

Check the field coil for ground.
Using an ohmmeter, check that there is no continuity be-
tween the field coil end and field frame.

If there is continuity, repair or replace the field frame.

4.

INSPECT BRUSHES

Using vernier calipers, measure the brush length.

Standard length:
15.5 mm (0.610 in.)
Minimum length:
8.5 mm (0.335 in.)

If the length is less than minimum, replace the brush holder and
field frame.

5.

INSPECT BRUSH SPRINGS

Check the brush spring load.

Take the pull scale reading the instant the brush spring
separates from the brush.
Standard spring installed load:
17.6 – 23.5 N (1.8 – 2.4 kgf, 3.9 – 5.3 lbf)
Minimum spring installed load:
11.8 N (1.2 kgf, 2.6 lbf)

If the installed load is less than minimum, replace the brush
springs.

P13481

No Continuity

Ohmmeter

B01162

Lock

Free

B01163

Ohmmeter

Terminal 50

Terminal C

Continuity

B01164

Ohmmeter

Terminal 50

Continuity

ST–10

–

STARTING

STARTER

LEXUS RX300 (RM785E)

6.

INSPECT BRUSH HOLDER

Check the brush holder insulation.

Using an ohmmeter, check that there is no continuity be-
tween the positive (+) and negative (–) brush holders.

If there is continuity, repair or replace the brush holder.
7.

INSPECT CLUTCH AND GEAR

(a)

Check the gear teeth on the pinion gear, idler gear and
clutch assembly for wear or damage.

If damaged, replace the gear or clutch assembly.
If damaged, also check the ring gear of the flywheel/drive plate
for wear or damage.

(b)

Check the clutch pinion gear.
Hold the starter clutch and rotate the pinion gear counter-
clockwise, and check that it turns freely. Try to rotate the
pinion gear clockwise and check that it locks.

If necessary, replace the clutch assembly.

8.

INSPECT MAGNETIC SWITCH

(a)

Check the pull–in coil for open circuit.
Using an ohmmeter, check that there is continuity be-
tween terminals 50 and C.

If there is no continuity, check and replace the magnetic switch.

(b)

Check the hold–in coil for open circuit.
Using an ohmmeter, check that there is continuity be-
tween terminal 50 and the switch body.

If there is no continuity, replace the magnetic switch.
9.

INSPECT BEARING

Turn the bearing by hand while applying inward force.
If resistance is felt or the bearing sticks, replace the bearing.
(See page ST–11)

ST09D–02

B01224

B01225

B01226

B01227

Stop Collar

Pinion Gear

Compression
Spring

B01228

–

STARTING

STARTER

ST–11

LEXUS RX300 (RM785E)

REPLACEMENT

1.

REPLACE CLUTCH ASSEMBLY

(a)

Disassemble the starter housing and the clutch assembly.
(1)

Mount a brass bar in a vise, and install the starter
housing and clutch assembly to the brass bar.

(2)

Push down the pinion gear.

(3)

Using a plastic–faced hammer, tap down the stop
collar.

(4)

Using a screwdriver, pry out the snap ring.

(5)

Remove the stop collar.

(6)

Remove the pinion gear.

(7)

Remove the compression spring.

(8)

Push down the starter housing, and remove the
spring retainer.

(9)

Disassemble the starter housing.

(10) Disassemble the starter clutch.
(11) Disassemble the compression spring.
(12) Disassemble the clutch shaft.