Steering linkage needs lubrication

Lubricate the steering linkage.

Low or uneven tire pressure

Inflate the tires to the recommended pressure.

Loose wheel bearings

Adjust or replace the wheel bearings.

Incorrect front wheel alignment (caster)

Check and align the front suspension.

Broken springs

Replace the springs.

Malfunctioning shock absorber

Check and replace the shock absorber.

Broken stabilizer shaft or a missing link

Replace the stabilizer shaft.