Subaru 2004 IMPREZA Service Manual page 46

POWER ASSISTED SYSTEM (POWER STEERING)
2. MEASUREMENT OF STEERING EFFORT
Step
1 CHECK STEERING EFFORT.
1)Stop the vehicle on a concrete road.
2)Start the engine.
3)Idle the engine.
4)Install the spring scale on the steering wheel.
5)Pull the spring scale at an right angle to
steering wheel, and measure both right and left
steering wheel effort.
NOTE:
When turning the steering more quickly than
necessary from a direction to the other direction
at an engine speed over 2,000 rpm, steering ef-
fort may be heavy. This is caused by flow char-
acteristic of oil pump and is not a problem.
2 CHECK STEERING EFFORT.
1)Stop the engine.
2)Pull the spring scale at an right angle to the
steering wheel, and measure both right and left
steering wheel effort.
3 CHECK STEERING WHEEL EFFORT.
1)Remove the universal joint.
2)Measure the steering wheel effort.
4 CHECK STEERING WHEEL EFFORT.
Measure the steering wheel effort.
5 CHECK UNIVERSAL JOINT.
Measure the folding torque of the joint (yoke of
steering column side). <Ref. to PS-24,
INSPECTION, Universal Joint.>
6 CHECK UNIVERSAL JOINT.
Measure the folding torque of the joint (yoke of
gearbox side). <Ref. to PS-24, INSPECTION,
Universal Joint.>
7 CHECK FRONT WHEEL.
Check the front wheel.
8 CHECK TIE-ROD ENDS.
Remove the tie-rod ends.
9 CHECK BALL JOINT.
Remove the ball joint.
10 CHECK GEARBOX.
Measure the rotating of gearbox.
<Ref. to PS-45, TURNING RESISTANCE OF
GEARBOX, INSPECTION, Steering Gearbox
[LHD MODEL].> or <Ref. to PS-62, TURNING
RESISTANCE OF GEARBOX, INSPECTION,
Steering Gearbox [RHD MODEL].>
11 CHECK GEARBOX.
Measure the sliding of gearbox.
<Ref. to PS-44, SERVICE LIMIT, INSPEC-
TION, Steering Gearbox [LHD MODEL].> or
<Ref. to PS-61, SERVICE LIMIT, INSPEC-
TION, Steering Gearbox [RHD MODEL].>
General Diagnostic Table
Check
Is the steering effort less than
29.4 N (3.0 kgf, 6.6 lb)?
Is the steering effort less than
400 N (41 kgf, 90 lb)?
Is the maximum steering effort
less than 2.26 N (0.23 kgf, 0.51
lb)?
Is the difference of steering
effort between clockwise and
counterclockwise less than
20%?
Is the folding torque less than
7.3 N (0.74 kgf, 1.64 lb)?
Is the folding torque less than
3.8 N (0.39 kgf, 0.86 lb)?
Are the front wheels for
unsteady revolution or rattling
and brake for dragging?
Are the tie-rod ends of suspen-
sion for unsteady revolution or
rattling?
Are the ball joints of suspen-
sion for unsteady revolution or
rattling?
Is the rotating resistance of
gear box less than 10.5 N (1.1
kgf, 2.4 lb)?
Is the difference between
clockwise and counterclock-
wise 20%?
Is the sliding resistance of gear
box less than 400 N (41 kgf, 90
lb)?
Is the difference between right
and left 20%?
PS-90
Yes
Go to step 2. Adjust the back-
lash.
Go to step 3. Perform adjust-
ment.
Go to step 4. Check, adjust and
replace if neces-
sary.
Go to step 5. Check, adjust and
replace if neces-
sary.
Go to step 6. Replace with new
one.
Go to step 7. Replace with new
one.
Inspect, readjust Go to step 8.
and replace if nec-
essary.
Inspect and Go to step 9.
replace if neces-
sary.
Inspect and Go to step 10.
replace if neces-
sary.
Go to step 11. Readjust the back-
lash, and if ineffec-
tive, replace the
faulty parts.
Steering effort is Readjust the back-
normal. lash, and if ineffec-
tive, replace the
faulty parts.
No