Self-Study Programme 448 Wheel alignment basics.pdf

(3850 KB) Pobierz
Service Training
Self-study Programme 448
Wheel Alignment – Basics
Today’s modern vehicles have increasingly complex and advanced suspension systems that need to fulfil the
requirements of comfort, sporty usage and especially road safety.
We now have very good means for measuring the suspension geometry and for correcting misaligned settings
to ensure that the high requirements set for the suspension system can also be met over the entire vehicle life
and after accidents.
S448_002
In this self-study programme, you will learn about the background of wheel alignment,
for example:
●
●
●
●
●
●
Suspension-related terms
Preparation of the wheel alignment system
Checking the wheel alignment system
Why the alignment is carried out
The tools used for wheel alignment
How the alignment principle works
For current testing, adjustment and repair
instructions, refer to the relevant service literature.
Important
Note
2
Contents
Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design configuration – vehicle position X-Y-Z axis system . . . . . . . . . . . . . . . .
Suspension-related terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
4
5
6
Wheel Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Why do the wheels need to be aligned? . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Workshop equipment for wheel alignment . . . . . . . . . . . . . . . . . . . . . . . . . . .
Carrying out the wheel alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
20
24
31
Using Wheel Alignment Stands For Other Systems . . . . . . . . . . . . . . . . . . . 38
Driver assistance systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Axles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Types of axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Flowchart for wheel alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3
Basics
Introduction
The suspension system is the connecting link between
the vehicle and the road. Wheel contact forces, drive
forces and the lateral forces in corners are all
transferred through the suspension onto the road via
the wheels.
The suspension system is therefore subjected to a
number of forces and moments.
Increasing vehicle performance figures and also
greater expectations for vehicle comfort and vehicle
safety have led to a constant increase in requirements
for the suspension.
The structural design in the suspension kinematics has
resulted in increasingly complex alignment processes
and smaller tolerances in the adjustments.
To measure and, if necessary, re-align the suspension
kinematics, the suspension needs to be checked and
adjusted on a special wheel alignment stand.
It should be noted that the suspension should only be
adjusted after repairs or problems with the
suspension.
This self-study programme will provide you with an overview of wheel alignment – starting with the terms and
going onto the actual alignment.
Suspension design
The suspension consists of
●
●
●
●
Wheel mountings
Wheels
Springs
Shock absorbers
●
●
●
●
Front and rear axles
Steering
Brakes including controls
Subframes
4
Design configuration – vehicle position in an X-Y-Z
axis system
The design configuration is first defined during the
development of a vehicle. It is described by an X-Y-Z
axis system.
The Z- and the X-axes run through the centre of the
front axle, and the Y-axis normally runs exactly
through the centre of the front wheels. The design
configuration corresponds with the vehicle position at
the nominal ride height.
All nominal data specified by the vehicle
manufacturer relate to the design configuration.
If data is collected and compared during the wheel
alignment, the design configuration is always taken as
a reference – this concerns the suspension terms
described below.
S448_035
Ride height
The ride height has a decisive influence on the results of the wheel alignment. It is influenced by the load carried in
the vehicle, by the contents of the fuel tank or other liquid containers and also by temperature differences that can
cause the suspension measurements, for example, toe, camber and caster, to change.
5

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin