Some vehicle drive train parts have remained
unchanged for many years. Most drive train systems, how-
ever, have undergone changes, and many new drive train
parts have been introduced. Many manual transmissions
now contain as many as six forward gears, compared to
the three-speed units of years ago. Components that were
rare in the past, such as transfer cases, limited-slip differen-
tials, and two-piece drive shafts, are increasingly found on
light trucks and SUVs. Transaxles and CV axles, once
novelties, are now used on most automobiles. Some vehi-
cles are equipped with completely new drive train systems,
such as electronically controlled transfer cases and
hydraulically locking differentials.
In the past, the drive train technician could learn by
doing, that is, learn about parts and systems as he or she
performed repairs. Today, this is no longer possible.
Experimentation cannot be tolerated in today’s competitive
repair market. Both labor and parts are too expensive to be
wasted on trial-and-error methods. Since many drive train
parts are controlled by or send a signal to the on-board
computer, the technician must have an understanding of
basic electricity and electronics and must know how to use
a scan tool to diagnose these drive train parts. Today’s
technician must also be aware of the special service tools
required by many components and the procedures used to
repair the more easily damaged drive train parts that are
made of aluminum and magnesium.
Manual Drive Trains and Axles provides theory and
service information for all modern drive train components.
This includes information on the latest versions of clutches,
manual transmissions and transaxles, solid and inde-
pendent rear axle assemblies, drive shafts and drive axles,
U-joints, CV joints, and center supports. Basic drive train
components such as gears, bearings, and seals are identi-
fied and explained, along with the principles of hydraulic
systems. The text also includes basic electricity and
electronic principles, detailed explanations of the opera-
tion of electronically controlled components, and overall
electronic control systems.
The textbook is arranged so that operating principles,
system designs, and component parts are fully explained
before diagnosis and repair procedures are discussed. Each
chapter begins with a list of objectives that identify the
focus of the chapter. The beginning of each chapter also
contains a list of important technical terms. Look for these
terms as you read through each chapter. They are presented
in bold italic type when first used in the text and are
defined when introduced. Figure references are presented
in bold type for ease of identification. Notes provide
supplemental information on the material presented in the
text. Cautions are presented when the risk of property
damage is possible. Warnings are presented when personal
injury is possible, either during service or when the vehicle is
operated after repairs. Each chapter closes with a
Summary, Review Questions, and ASE-Type Questions.
In a few years, it will become difficult for the automo-
tive technician to get a job if he or she is not ASE certified.
The National Institute for Automotive Service Excellence,
or ASE, was established almost 30 years ago to increase
technician standards by, among other things, giving a
series of standardized tests in various automotive areas.
Manual Drive Trains and Axles is a valuable aid to those
preparing for the ASE certification test A3, Manual Drive
Trains and Axles. The content is correlated to the
ASE/NATEF task list. ASE-type questions at the end of each
chapter help prepare you for the kinds of questions asked
on the ASE tests. In addition, Chapter 21 provides informa-
tion on preparing for and taking the ASE tests.
A workbook correlated to Manual Drive Trains and
Axles is also available. The workbook contains additional
test questions, including more ASE-type questions. The
chapters in the workbook are correlated to those in the
textbook. The workbook also has drive train related jobs
that develop your ability to perform hands-on service.
By choosing Manual Drive Trains and Axles, you have
made a good start in preparing for a future in the field of
automotive service and repair.
Chris Johanson
3
Introduction