Caster Description. Pontiac Sun Runner - 4WD (Canada) 1998

For 1990-2009 cars

Caster is the tilt of the highest point of the steering axis from the vertical. The caster is viewed from the side of the vehicle.

The caster can lean either forward or backward.

• | A backward tilt is positive (+)

• | A forward tilt is negative (-)

The caster influences directional control of the steering. The caster does not affect tire wear.

The vehicle height affects castor. Therefore, it is necessary to keep the body at its designated height.

The following conditions affect the caster:

• | An overload of the vehicle

• | A weak or sagging rear spring

When the rear of the vehicle is lower than the rear's designed trim height, the front suspension moves to a more positive caster.

If the rear of the vehicle is higher than the rear's designated trim height, the front suspension moves to a less positive caster.

Refer to Wheel Alignment Specifications in this section for caster specifications.