Subaru Legacy IV (2008 year). Manual - part 727

5AT-32

Stall Test

AUTOMATIC TRANSMISSION

5. Stall Test

A: INSPECTION

NOTE:
The stall test is extremely important in diagnosing
the condition of an automatic transmission and en-
gine. The test is necessary to measure the engine
stall speeds in “2nd of manual mode”.
Purposes of the stall test:
• Operational check of the automatic transmission
clutch
• Operational check of the torque converter clutch
• Engine performance check
1) Check that the throttle valve fully opens.
2) Check that the engine oil level is correct.
3) Check that the coolant level is correct.
4) Check that the ATF level is correct.
5) Check that the differential gear oil level is cor-
rect.
6) Raise the ATF temperature to 70 to 80°C (158 to
176°F) by driving a distance of 5 to 10 km (3 to 6
mile). Confirm the ATF temperature on Subaru Se-
lect Monitor. <Ref. to 5AT(diag)-18, READ CUR-
RENT DATA, OPERATION, Subaru Select
Monitor.>
7) Place the wheel chocks at the front and rear of
all wheels and apply the parking brake.
8) Move the manual linkage to ensure it operates
properly, then set to “2nd gear of manual mode”.
9) While stepping hard on the brake pedal, gradu-
ally step on the accelerator pedal.
10) When the engine speed is stabilized, quickly
record the engine speed and release accelerator
pedal.

5AT-33

Stall Test

AUTOMATIC TRANSMISSION

11) Shift the select lever to “N” range, and cool
down the engine by idling it for one minute or more.

NOTE:
• Do not perform a stall test for over 5 seconds at
a time. (Perform with the throttle from fully closed to
fully open to end up reading the stall speed.) Doing
so will make the engine oil and ATF deteriorate and
the clutch and brake to be adversely affected.
• After performing the stall test, be sure to cool
down the engine for at least one minute with the se-
lect lever set in “P” or “N” range, and at an idle
speed of 1,200 rpm or less.
• If the stall speed is higher than the specified
range, attempt to finish the stall test in as short a
time as possible, in order to prevent the automatic
transmission from sustaining damage.
• Perform the stall test in S mode.
• When depressing the accelerator pedal again af-
ter performing the stall test for 5 seconds or more,
the electronic throttle control remains closed for ap-
prox. 60 seconds.
• When the stall test is performed for 15 seconds
or more continuously, the test is completed forcibly
to protect the transmission unit.
When depressing the accelerator pedal again, the
electronic throttle control remains closed for ap-
prox. 60 seconds.

Stall speed (at sea level):

Turbo model

2,300 — 3,200 rpm

Non-turbo model

1,900 — 2,200 rpm

Stall speed (at sea level)

Range

Possible faulty parts

Over specified value

2nd gear of manual mode

• Line pressure too low
• Forward brake
• Direct clutch
• 3rd one-way clutch

5AT-34

Time Lag Test

AUTOMATIC TRANSMISSION

6. Time Lag Test

A: INSPECTION

NOTE:
When the select lever is shifted while the engine is
idling, there will be a certain time elapse or lag be-
fore shock is felt. Using this, check the condition of
forward brake, reverse brake, 1st one-way clutch
and 3rd one-way clutch.
• Perform the test at normal operation fluid tem-
perature of 70 — 80°C (158 — 176°F).
• Be sure to allow one minute or more interval be-
tween tests.
• Make three measurements and take the average
value.
1) Fully apply the parking brake.
2) Start the engine.
Check the idle speed (A/C OFF).
3) Shift the select lever from “N” to “D” range. Using
a stop watch, measure the time-lag from shifting
the lever until the shock is felt.

Time-lag

Standard: 1.2 seconds or less

If “N” 

o “D” time-lag is longer than specification:

• Line pressure too low
• Forward brake worn
• One-way clutch not operating properly
4) In the same manner, measure the time lag of “N”
o “R”.

Time-lag

Standard: 1.5 seconds or less

If “N” 

o “R” time lag is longer than specification:

• Line pressure too low
• Reverse brake worn

5AT-35

Line Pressure Test

AUTOMATIC TRANSMISSION

7. Line Pressure Test

A: MEASUREMENT

NOTE:
If the clutch or brake shows a sign of slippage, or
shifting interval is not correct, check the line pres-
sure.
• Excessive shock during up-shift may be due to
the line pressure being too high.
• Slippage or inability to operate the vehicle may,
in most cases, be due to loss of oil pressure for the
operation of clutch, brake or control valve.
1) Set the vehicle on a lift.
2) Remove the under cover.
3) Remove the test plug and attach the ST.
ST

498897200

OIL PRESSURE ADAPTER

4) Set the ST1 and ST2.
ST1

498897200

OIL PRESSURE ADAPTER

ST2

498575400

OIL PRESSURE GAUGE 
ASSY

5) Lower the vehicle, and pull ST2, which were set
in step 4), into the vehicle.
6) Connect the Subaru Select Monitor to the data
link connector and read the current data. <Ref. to
5AT(diag)-18, READ CURRENT DATA, OPERA-
TION, Subaru Select Monitor.>

AT-01752