Thursday, September 13, 2012

Car care: troubleshooting suspension problems

[Article copyright Ewe Paik Leong]

There are two types of suspensions: strut suspension or conventional suspension.

Most front-wheel drive cars have strut suspension where the strut has a built-in shock absorber. The car is supported by a coil spring with a bearing plate at its upper end and a seat at its lower end. Two half drive-shafts and four constant velocity universal joints carry engine torque to the front drive wheels.

In the conventional suspension, two control arms are attached to the inner and outer ends of the frame by shafts and ball joints (via a steering knuckle) respectively. A coil spring and shock absorber are located between the frame and either the lower and upper control arm.

Shock absorbers and strut assemblies work with the springs and tyres to make your car ride smoother and safer over rough surfaces.

Symptoms of bad shock absorbers include the following:

--car bounces excessively after going over a bump,
--car nose-dives when brakes are applied,
--steering control is poor when car changes direction, and
--car sags in the front or rear instead of being level when it is stationary.

Worn-out springs will cause the car to bottom-out, sag, and swerve excessively.

When the constant velocity joints are faulty, clicking or clacking noises are heard when the car is executing sharp turns.

Improper alignment leads to excessive or uneven tyre wear, steering wheel vibration, steering-wheel pull to one side, car vibration as speed increases, and changes in direction when car hits a bump.

Excessive tyre wear to the inside or outside of the tyre treads is a result of incorrect toe. (The distance between the front of the wheels compared to the back of the wheels is called toe).

When a car's wheels are not equal distance from its centreline, problems include excessive wear of front tyres, poor steering control, and an off-centred steering wheel position.


Published by Monsoon Books, Singapore. Sold in Malaysia from Kinokuniya, Popular Book Store, Borders and MPH nationwide. An e-book edition is also available.


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