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STEERING
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1.2. MAINTENANCE, INSPECTION AND TEST
1.2.1 PRELIMINARY INSPECTION
A. INSPECTION OF TYRE
Tyre wear pattern are a good indicators of the condi-
tion of the steering and suspension system. Hence
the tyre wear pattern should be observed carefully
for wear patterns that indicate wrong or lost wheel
alignment. For detailed interpretation of Wear pattern
refer Wheels and Tyres Section.
B. STEERING WHEEL FREE PLAY
Check steering wheel play.
(Refer steering wheel
alignment in regular maintenance)
C. TEST DRIVE
During test drive pay close attention to any steering
ball joint sounds and steering column vertical slack-
ness, usually observed in rough patched of road.
At speeds above 40 km-ph on an even road if the
steering wheel vibrates (wobbles), it might be mainly
due to out of balance wheel.
D. ROAD TEST
Before releasing the vehicle, take it for road tests.
E. ACTIVE RETURN FEATURE / STEERING RE-
TURN ABILITY
Active Return / Steering return ability is the feature
which Twist returns the steering wheel back to its
straight-ahead position when wheel is released by
driver after taking a turn. This is achieved by provid-
ing a calibrated return torque through the system;
Further, System also provides self-centering action
giving driver confidence and stability at higher
speeds.
Active return ability will activate only after the ini-
tialization & Initialization will happen automatically
in 2 scenarios as below,
Lock to lock steering wheel rotation.
Once vehicle speeds achieved 30 kmph.
Check the following:
1. SELF-CENTERING TEST
(WITHOUT LOAD)
Drive the vehicle in second gear at about 10-15
Kmph along a circle of 10 meter radius and leave the
steering wheel. The vehicle should come back to
straight ahead condition freely. Conduct tests for
both left and right turns.
2. STEERING EFFORT TEST
Check the steering effort while negotiating a sharp
turn of about 10m radius at low speeds of 10-15
km/hr. Check that steering effort is satisfactory.
3. ROAD HOLDING ABILITY TEST
a. Drive the vehicle on level road at 40 km/hr with
steering wheel left free. Check whether there is
any tendency of vehicle to pull to either left or
right.
b. Check for unusual vibration or wobbling of the
wheel.
c. Check for absence of road shocks on steering
wheel.
4. TURNING CIRCLE TEST
With wheel turned to lock, drive at 5-10 km/hr.
Check whether the required turning circle is
achieved. Repeat for both left and right turns. Ensure
that for all steering Tests the required road safety
precautions are followed. In case performance is not
satisfactory during road tests. Trace and rectify the
defects.
5. STEERING EFFORT TEST IN STATIONARY
CONDITION
Steering effort in stationary condition is < 2 Kg with
EPAS
Effort can be measured in 2 conditions
1. Effort before lock condition
2. Lock to lock average effort