Opel Frontera UE. Manual - part 650
POWER-ASSISTED STEERING SYSTEM
2A–13
Caster:
This illustration shows view from the side of the vehicle.
480RS005
Caster (1) is the vertical tilting of the wheel axis either
forward or backward (when viewed from the side of the
vehicle). A backward tilt is positive (+) and a forward tilt
is negative (-). On the short and long arm type
suspension you cannot see a caster angle without a
special instrument, but if you look straight down from the
top of the upper control arm to the ground, the ball
joints do not line up (fore and aft) when a caster angle
other than 0 degree is present. With a positive angle,
the lower ball joint would be slightly ahead (toward the
front of the vehicle) of the upper ball joint center line.
Toe-in:
This illustration shows view from the top of the vehicle.
480RS003
Toe-in is the measured amount the front wheels are turn
in. The actual amount of toe-in is normally a fraction of
a degree. Toe-in is measured from the center of the tire
treads or from the inside of the tires. The purpose of
toe-in is to insure parallel rolling of the front wheels and
to offset any small deflections of the wheel support
system which occurs when the vehicle is rolling forward.
Incorrect toe-in results in excessive toe-in and unstable
steering. Toe-in is the last alignment to be set in the
front end alignment procedure.
Inspection
Before making any adjustments affecting caster, camber
or toe-in, the following front end inspection should be
made.
1. Inspect the tires for proper inflation pressure. Refer
to Main Data and Specifications in Wheel and Tire
System section.
2. Make sure that the vehicle is unladen condition
(With no passenger or loading).
3. Make sure that the spare tire is installed at the
normal position.
4. Inspect the front wheel bearings for proper
adjustment. Refer to Front Hub and Disc in
Driveline section.
5. Inspect the ball joints and tie rod ends. If excessive
looseness is noted, correct before adjusting. Refer
to Steering Linkage in this section.
6. Inspect the wheel and tires for run-out. Refer to
Wheel Replacement in Wheel and Tire System
section.
7. Inspect the trim height. If not within specifications,
the correction must be made before adjusting
caster.
8. Inspect the steering unit for looseness at the frame.
9. Inspect shock absorbers for leaks or any noticeable
noise. Refer to Shock Absorber in Suspension
section.
10. Inspect the control arms or stabilizer bar attachment
for looseness. Refer to Suspension section .
11. Inspect the front end alignment using alignment
equipment. Follow the manufacturer's instructions.
12. Park the vehicle must be on a level surface.