differential SUBARU IMPREZA 2007 3.G User Guide

7-20Starting and operating
Limited slip differential (LSD)
(if equipped)
The LSD provides optimum distribution of
power according to the difference in
revolutions between the right and left
wheels that may be caused by certain
driving conditions, thereby improving driv-
ing stability on snow-covered, muddy or
other slippery roads or when high speeddriving.
CAUTION
. Never start the engine while a tire
on one side is jacked up, as the
vehicle may move.
. If one tire is spinning in mud,
avoid continued spinning at high
speed as this could adversely
affect the LSD.
. If you use a temporary spare tire
to replace a flat tire, be sure to
use the original temporary spare
tire stored in the vehicle. Using
other sizes will adversely affect
the LSD. Power steering
The power steering system operates only
when the engine is running.
If you lose power steering assist because
the engine stops or the system fails to
function, you can steer but it will take
much more effort. NOTE
Right after the engine has been started
and before it has warmed up, you may
hear a noise coming from areas adja-
cent to the power steering pump which
is located at the right-front area of the
engine compartment. This noise is
normal. It does not indicate power
steering system trouble.
CAUTION
Do not hold the steering wheel at the
fully locked position left or right for
more than 5 seconds. This may
damage the power steering pump. Braking &
Braking tips
WARNING
Never rest your foot on the brake
pedal while driving. This can cause
dangerous overheating of the
brakes and needless wear on the
brake pads and linings.
! When the brakes get wet
When driving in rain or after washing the
vehicle, the brakes may get wet. As a
result, brake stopping distance will be
longer. To dry the brakes, drive the vehicle
at a safe speed while lightly depressing
the brake pedal to heat up the brakes. ! Use of engine braking
Remember to make use of engine braking
in addition to foot braking. When descend-
ing a grade, if only the foot brake is used,
the brakes may start working improperly
because of brake fluid overheating,
caused by overheated brake pads. To
help prevent this, shift into a lower gear to
get stronger engine braking.

8-20Driving tips
Trailer towing
Your vehicle is designed and intended to
be used primarily as a passenger-carrying
vehicle. Towing a trailer puts additional
loads on your vehicle ’s engine, drivetrain,
brakes, tires and suspension and has an
adverse effect on fuel economy.
If you do decide to tow a trailer, your safety
and satisfaction depend upon proper use
of correct equipment and cautious opera-
tion of your vehicle. Seek the advice of
your SUBARU dealer to assist you in
purchasing a hitch and other necessary
towing equipment appropriate for your
vehicle. In addition, be sure to follow the
instructions on correct installation and use
provided by the trailer and other towing
equipment manufacturers.
SUBARU assumes no responsibility for
injuries or vehicle damage that result from
trailer towing equipment, or from any
errors or omissions in the instructions
accompanying such equipment or for your
failure to follow the proper instructions.
& Warranties and maintenance
SUBARU warranties do not apply to
vehicle damage or malfunction caused
by trailer towing. If you use your vehicle to
tow a trailer, more frequent maintenance
will be required due to the additional load. (Refer to
“Maintenance schedule under
severe driving conditions ”in the “Warranty
and Maintenance Booklet ”.)
Under no circumstances should a trailer
be towed with a new vehicle or a vehicle
with any new powertrain component (en-
gine, transmission, differential, wheel
bearings, etc.) for the first 1,000 miles
(1,600 km) of driving.
& Maximum load limits
WARNING
Never exceed the maximum load
limits explained in the following.
Exceeding the maximum load limits
could cause personal injury and/or
vehicle damage.
CAUTION
. Adequate size trailer brakes are
required when the trailer and its
cargo exceed 1,000 lbs (453 kg)
total weight.
. Before towing a trailer, check the
trailer total weight, GVW, GAWs
and tongue load. Make sure the
load and its distribution in your
vehicle and trailer are accepta- ble.
! Total trailer weight
Total trailer weight
The total trailer weight (trailer weight plus
its cargo load) must never exceed the
maximum weight shown in the followingtable.

Engine overheating
WARNING
Never attempt to remove the radia-
tor cap until the engine has been
shut off and has fully cooled down.
When the engine is hot, the coolant
is under pressure. Removing the
cap while the engine is still hot
could release a spray of boiling hot
coolant, which could burn you very
seriously.
If the engine overheats, safely pull off the
road and stop the vehicle in a safe place. & If steam is coming from the
engine compartment
Turn off the engine and get everyone
away from the vehicle until it cools down. & If no steam is coming from
the engine compartment
1. Keep the engine running at idling speed.
2. Open the hood to ventilate the engine compartment.
Confirm that the cooling fan is turning. If
the fan is not turning, immediately turn off the engine and contact your authorized
dealer for repair.
3. After the engine coolant temperature
has dropped, turn off the engine.
If the temperature gauge stays at the
overheated zone, turn off the engine.
4. After the engine has fully cooled down,
check the coolant level in the reservetank.
If the coolant level is below the
“LOW ”
mark, add coolant up to the “FULL ”mark.
5. If there is no coolant in the reserve
tank, add coolant to the reserve tank.
Then remove the radiator cap and fill the
radiator with coolant.
If you remove the radiator cap from a hot
radiator, first wrap a thick cloth around the
radiator cap, then turn the cap counter-
clockwise slowly without pressing down
until it stops. Release the pressure from
the radiator. After the pressure has been
fully released, remove the cap by pressing
down and turning it. Towing
If towing is necessary, it is best done by
your SUBARU dealer or a commercial
towing service. Observe the following
procedures for safety.
WARNING
Never tow AWD vehicles (both AT
and MT) with the front wheels raised
off the ground while the rear wheels
are on the ground, or with the rear
wheels raised off the ground while
the front wheels are on the ground.
This will cause the vehicle to spin
away due to the operation or dete-
rioration of the center differential. In case of emergency
9-11
– CONTINUED –

Maintenance schedule....................................... 11-3
Maintenance precautions ................................... 11-3
Before checking or servicing in the engine compartment .................................................... 11-4
When you do checking or servicing in the engine compartment while the engine is running .......... 11-4
Engine hood ....................................................... 11-4
Engine compartment overview .......................... 11-6
Non-turbo models .............................................. 11-6
Turbo models ..................................................... 11-7
Engine oil ............................................................ 11-8
Checking the oil level ......................................... 11-8
Changing the oil and oil filter .............................. 11-9
Recommended grade and viscosity .................. 11-11
Recommended grade and viscosity under severe driving conditions .......................................... 11-12
Synthetic oil ..................................................... 11-12
Cooling system ................................................ 11-12
Cooling fan, hose and connections ................... 11-12
Engine coolant ................................................. 11-13
Air cleaner element .......................................... 11-15
Replacing the air cleaner element ..................... 11-15
Spark plugs ...................................................... 11-17
Recommended spark plugs .............................. 11-18
Drive belts ........................................................ 11-18
Manual transmission oil .................................. 11-19
Checking the oil level ....................................... 11-19
Recommended grade and viscosity .................. 11-20
Automatic transmission fluid .......................... 11-20
Checking the fluid level .................................... 11-20 Recommended fluid
......................................... 11-21
Front differential gear oil (AT vehicles) .......... 11-21
Checking the oil level ...................................... 11-21
Recommended grade and viscosity .................. 11-22
Rear differential gear oil .................................. 11-22
Checking the gear oil level ............................... 11-22
Recommended grade and viscosity .................. 11-23
Power steering fluid ........................................ 11-24
Checking the fluid level .................................... 11-24
Recommended fluid ......................................... 11-25
Brake fluid ........................................................ 11-25
Checking the fluid level .................................... 11-25
Recommended brake fluid ............................... 11-26
Clutch fluid (MT vehicles) ............................... 11-26
Checking the fluid level .................................... 11-26
Recommended clutch fluid ............................... 11-27
Brake booster .................................................. 11-27
Brake pedal ...................................................... 11-27
Checking the brake pedal free play .................. 11-27
Checking the brake pedal reserve distance....... 11-28
Clutch pedal (MT vehicles) .............................. 11-28
Checking the clutch function ............................ 11-28
Checking the clutch pedal free play .................. 11-28
Replacement of brake pad and lining ............ 11-29
Breaking-in of new brake pads and linings ....... 11-29
Parking brake stroke ....................................... 11-30
Tires and wheels .............................................. 11-30
Types of tires ................................................... 11-30
Tire inspection ................................................. 11-30
Tire pressures and wear .................................. 11-31
Maintenance and service
11

11-6Maintenance and service
Engine compartment overview &Non-turbo models1) Air cleaner element (page 11-15)
2) Manual transmission oil level gauge (MT)
(page 11-19) or Differential gear oil level
gauge (AT) (page 11-21)
3) Clutch fluid reservoir (page 11-26)
4) Automatic transmission fluid level gauge (page 11-20)
5) Brake fluid reservoir (page 11-25)
6) Fuse box (page 11-42)
7) Battery (page 11-41)
8) Windshield washer tank (page 11-36)
9) Engine coolant reservoir (page 11-13)
10) Engine oil level gauge (page 11-8)
11) Engine oil filler cap (page 11-8)
12) Radiator cap (page 11-13)
13) Power steering fluid reservoir (page 11- 24)

&Turbo models1) Air cleaner element (page 11-15)
2) Manual transmission oil level gauge (MT)
(page 11-19) or Differential gear oil level
gauge (AT) (page 11-21)
3) Automatic transmission fluid level gauge (page 11-20)
4) Clutch fluid reservoir (page 11-26)
5) Brake fluid reservoir (page 11-25)
6) Fuse box (page 11-42)
7) Battery (page 11-41)
8) Windshield washer tank (page 11-36)
9) Engine oil filler cap (page 11-8)
10) Engine coolant reservoir (page 11-13)
11) Engine oil level gauge (page 11-8)
12) Radiator cap (page 11-13)
13) Power steering fluid reservoir (page 11- 24)Maintenance and service
11-7

4. Pull out the dipstick and check the fluid
level on the gauge. If it is below the lower
level on the“HOT ”range, add the recom-
mended automatic transmission fluid up to
the upper level. ! Checking the fluid level when the
fluid is cold
When the fluid level has to be checked
without time to warm up the automatic
transmission, check to see that the fluid
level is between the lower level and upper
level on the “COLD ”range. If it is below
that range, add fluid up to the upper level.
Be careful not to overfill.
CAUTION
Be careful not to spill automatic
transmission fluid when adding it.
If automatic transmission fluid
touches the exhaust pipe, it may
cause a bad smell, smoke, and/or a
fire. If automatic transmission fluid
gets on the exhaust pipe, be sure to
wipe it off. &
Recommended fluid
Use one of the following types of auto-
matic transmission fluid. Genuine Subaru Automatic Transmis-
sion Fruid Type-HP
IDEMITSU ATF HP
Castrol Transmax J
Pennzoil ATF-J*
* Available only in the USA (except
Alaska and Hawaii)
NOTE
For optimum transmission perfor-
mance, only use the automatic trans-
mission fluid that is recommended and
provided by Subaru.
If the recommended automatic trans-
mission fluid is unavailable, Dexron III
may be temporarily used. If the Dexron
III is used continuously there will be a
noticeable increase in the vibration and
noise from the automatic transmission. Front differential gear oil (AT
vehicles) &
Checking the oil level
1) Yellow handle
1. Park the vehicle on a level surface and
stop the engine.
2. Pull out the dipstick, wipe it clean, and
insert it again. Maintenance and service
11-21
– CONTINUED –

11-22Maintenance and service
1) Upper level
2) Lower level
3. Pull out the dipstick again and check
the oil level on it. If it is below the lower
level, add oil to bring the level up to the
upper level.
CAUTION
Be careful not to spill front differ-
ential gear oil when adding it. If oil
touches the exhaust pipe, it may
cause a bad smell, smoke, and/or a
fire. If oil gets on the exhaust pipe,
be sure to wipe it off. &
Recommended grade and viscosity
Each oil manufacturer has its own base
oils and additives. Never use different
brands together.
Oil grade: API classification GL-5
SAE viscosity No. and applicable tempera- ture Rear differential gear oil &
Checking the gear oil level
Your vehicle may be equipped with a rear
differential protector. The differential pro-
tector provides protection to the rear
differential assembly during off-road use.
Removal of the rear differential protector is
not required when checking the oil level.1) Filler plug
2) Drain plug

1) Filler hole
2) Drain hole
3) Oil level
Remove the plug from the filler hole and
check the oil level. The oil level should be
kept even with the bottom of the filler hole.
If the oil level is below the bottom edge of
the hole, add oil through the filler hole to
raise the level.
CAUTION
. Be careful not to spill rear differ-
ential gear oil when adding it. If
rear differential gear oil touches
the exhaust pipe, it may cause a
bad smell, smoke, and/or a fire. If
rear differential gear oil gets on
the exhaust pipe, be sure to wipe it off.
. If the vehicle requires frequent
refilling, there may be an oil leak.
If you suspect a problem, have
the vehicle checked at your
SUBARU dealer. &
Recommended grade and viscosity
Each oil manufacturer has its own base
oils and additives. Never use different
brands together.
Oil grade: API classification GL-5SAE viscosity No. and applicable tempera- ture Maintenance and service
11-23

12-4Specifications
&Capacities
Fuel tank 15.9 US gal (60 liters, 13.2 Imp gal)
Engine oil 4.2 US qt (4.0 liters, 3.5 Imp qt)
Transmission oil (MT) 5-speed 3.7 US qt (3.5 liters, 3.1 Imp qt)
6-speed 4.3 US qt (4.1 liters, 3.6 Imp qt)
Front differential gear oil (AT) 1.3 US qt (1.2 liters, 1.1 Imp qt)
Rear differential gear oil WRX-STI 1.1 US qt (1.0 liters, 0.9 Imp qt)
Others 0.8 US qt (0.8 liters, 0.7 Imp qt)
Transmission fluid (AT) 10.0 US qt (9.5 liters, 8.4 Imp qt)
Power steering fluid 0.7 US qt (0.7 liter, 0.6 Imp qt)
Engine coolant Non-turbo engine MT7.4 US qt (7.0 liters, 6.2 Imp qt)
AT 7.3 US qt (6.9 liters, 6.1 Imp qt)
Turbo engine MT 8.1 US qt (7.7 liters, 6.8 Imp qt)
AT 8.0 US qt (7.6 liters, 6.7 Imp qt)
AT: Automatic transmission
MT: Manual transmission