Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 117

SC(STI)-24

Generator

STARTING/CHARGING SYSTEMS

(3) Disconnect the connection and remove the

brush.

10) Remove the rectifier as follows.

(1) Remove the bolts which secure the rectifier.

(2) Remove the cover on terminal B.

(3) Remove the nuts of terminal B, then remove

the rectifier.

D: ASSEMBLY

Assemble in the reverse order of disassembly.
NOTE:

• Refer to component for tightening torque of each

part. <Ref. to SC(STI)-5, GENERATOR, COMPO-

NENT, General Description.>

• After assembling, manually turn the pulley to

check that the rotor rotates smoothly.

1) Push of the brush

Before assembling the front and rear parts, press

the brush down into the brush holder, then fix the

brush in that position by inserting a wire [1 mm

(0.08 in) dia., 40 — 50 mm (1.6 — 2.0 in) long]

through the hole as shown in the figure.
CAUTION:

After assembling, remove the wire.

2) Install the ball bearings

(1) Set the ball bearings in the front cover, then

securely install an appropriate tool (such as a

socket wrench of proper size) to the bearing

outer race.

(2) Using a press to press the ball bearings into

the specified location.

(3) Install the bearing retainer.

3) Install the bearings.
CAUTION:

Do not apply grease to the bearings. If there is

any oil on the bearing box, remove it complete-

ly.

(1) Use a press to install the bearings to the ro-

tor shaft.

(2) Heat the bearing box in rear cover at 50 to

60°C (122 to 140°F), and then press the bear-

ing into rear cover.

SC-00088

SC-00089

SC-00090

SC-00091

(A) Wire

SC-00092

(A)

SC(STI)-25

Generator

STARTING/CHARGING SYSTEMS

E: INSPECTION

1. DIODE

CAUTION:

There is the possibility of damaging the diodes

if a mega-tester (used to measure high voltag-

es) or a similar measuring instrument is used.

Never use a mega tester or equivalent for this

test.

1) Check for continuity between the diode lead and

positive side heat sink. If resistance is 1 Ω or more

only in the direction from the diode lead to the heat

sink, replace the rectifier.

2) Check for continuity between the negative side

heat sink and diode lead. If resistance is 1 Ω or

more only in the direction from the heat sink to the

diode lead, replace the rectifier.

2. ROTOR

1) Inspect the slip rings for contamination or any

roughness on the sliding surface. Repair the slip

ring surface using a lathe or sand paper.

2) Measure the slip ring outer diameter. Replace

the rotor if the slip ring is worn.
Slip ring outer diameter:

Standard

22.7 mm (0.894 in)

Limit

22.1 mm (0.870 in)

3) Using a circuit tester, check the resistance be-

tween slip rings. If resistance exceeds the stan-

dard, replace the rotor.
Standard:

Approx. 1.8 — 2.2

Ω

4) Check the continuity between slip ring and rotor

core or shaft. If there is continuity, replace the rotor

because the rotor coil is grounded.

5) Check the bearings. If there is any noise, or the

rotor does not rotate smoothly, replace the bear-

ings.

(A) Diode lead
(B) Heat sink (positive side)

(A) Diode lead
(B) Heat sink (negative side)

SC-00042

(B)

(A)

(A)

(B)

SC-00043

SC-00044

SC-00045

SC(STI)-26

Generator

STARTING/CHARGING SYSTEMS

3. STATOR COIL

1) Inspect continuity between the stator coil lead

wire terminals. If the resistance is 1 MΩ or more, re-

place the stator coil.

2) Inspect the continuity between the stator coil sta-

tor core and lead wire terminals. If the resistance is

1 Ω or less, replace the stator coil.

4. BRUSH

1) Measure the length of each brush. Replace the

brush if wear exceeds service limits. There is a ser-

vice limit mark (A) on each brush.
Brush length:

Standard (1)

18.5 mm (0.728 in)

Limit (2)

5.0 mm (0.197 in)

2) Using a spring pressure indicator, push the

brush into the brush holder until its tip protrudes 2

mm (0.08 in). Then measure the pressure of brush

spring. If the pressure is 2.648 N (270 g, 9.52 oz) or

less, replace the brush spring with a new part.

4.609 — 5.786 N (470 — 590 g, 16.58 — 20.810

oz) pressure is required on the new spring.

5. BALL BEARING

Check the ball bearings. Replace the ball bearings

if there is resistance in the rotation, or if there is any

abnormal noise.

6. OTHER INSPECTIONS

Check that the generator does not have deforma-

tion, cracks and any other damage.

(A) Stator coil

(A)

SC-00047

SC-00048

SC-02313

(A)

(1)

(2)

SC-00093

SC(STI)-27

Battery

STARTING/CHARGING SYSTEMS

4. Battery

A: REMOVAL

1) Disconnect the positive (+) terminal after discon-

necting the negative (–) terminal of battery.

2) Remove the harness clip of the negative termi-

nal from the battery rod.

3) Remove the flange nut from battery rod and re-

move battery holder.

4) Remove the battery.

B: INSTALLATION

Install in the reverse order of removal.
Tightening torque:

3.5 N·m (0.4 kgf-m, 2.6 ft-lb)

NOTE:

• Clean the battery cable terminals and apply

grease to retard the formation of corrosion.

• Connect the positive (+) terminal, and then con-

nect the negative (–) terminal of the battery.

• After the battery is installed, initial diagnosis of

the electronic throttle control is performed. Wait for

10 seconds or more after turning the ignition switch

to ON, and then start the engine.

C: INSPECTION

WARNING:

• Electrolyte is corrosive acid, and has toxici-

ty; be careful of handling the fluid.

• Make sure the electrode does not come into

contact with skin, eyes or clothing. Especially

at contact with eyes, flush with water for 15

minutes and get prompt medical attention.

• In addition, be careful not to let the electrode

contact with the coated parts.

• Be careful when handling the batteries be-

cause they produce explosive gases.

• Be sure to keep battery away from any fire.

• For safety, in case an explosion does occur,

wear eye protection or shield your eyes when

working near any battery. In addition, never

lean over the battery.

• Ventilate sufficiently when using or charging

battery in enclosed space.

• Before starting work, remove rings, metal

watch-bands, and other metal jewelry.

• Never allow metal tools to contact the posi-

tive battery terminal and anything connected to

it while you are at the same time in contact with

any other metallic portion of the vehicle.

1. EXTERNAL PARTS

Check the battery case, top cover, vent plugs, and

terminal posts for dirt or cracks. If necessary, clean

with water and wipe with a dry cloth.

Apply a thin coat of grease on the terminal posts to

prevent corrosion.

2. ELECTROLYTE LEVEL

Check the electrolyte level in each cell. If the level

is below MIN level, bring the level to MAX level by

pouring distilled water into the battery cell. Do not

fill beyond MAX level.

3. SPECIFIC GRAVITY OF ELECTROLYTE

1) Measure specific gravity of electrolyte using a

hydrometer and a thermometer.

Specific gravity varies with temperature of electro-

lyte so that it must be corrected at 20°C (68°F) us-

ing the following calculation:
S

20

= St + 0.0007 × (t – 20)

S

20

: Specific gravity corrected at electrolyte

temperature of 20°C (68°F)

St: Measured specific gravity

t: Measured temperature (°C)

Judge whether or not the battery requires

charging according to corrected specific

gravity.

Standard specific gravity: 1.220 — 1.290 [at

20°C (68°F)]

SC-02238