SCOPE AND USE OF THE MANUAL
This section covers the basic Series 71 In-line diesel engines built by the Detroit Diesel Allison Division of General
Motors Corporation. Multiple engine units are available in various combinations such as side-by-side twins, tandem twins
and quads. Complete instructions on operation, adjustment (tune-up), preventive maintenance and lubrication, and
repair (including complete overhaul) are covered. The manual was written primarily for persons servicing and
overhauling the engine and, in addition, contains all of the instructions essential to the operators and users. Basic
maintenance and overhaul procedures are common to all Series 71 In-line engines and therefore apply to all engine
This section is divided into numbered chapters. The first chapter covers the engine (less major assemblies). The
following chapters cover a complete system such as the fuel system, lubrication system or air system. Each chapter is
divided into sub-sections which contain complete maintenance and operating instructions for a specific sub-assembly on
the engine. For example, Chapter 1, which covers the basic engine, contains a sub-section pertaining to the cylinder
block, another sub-section covering the cylinder head, etc. The subjects and chapters are listed in the Table of Contents
on the preceding page. Pages are numbered consecutively, starting with a new Page 1 at the beginning of each sub-
section. The illustrations are also numbered consecutively. beginning with a new Figure 1 at the start of each chapter.
Information regarding a general subject, such as the lubrication system, can best be located by using the Table of
Contents. Opposite each subject in the Table of Contents is a chapter number. Information on a specific sub-assembly
or accessory can then be found by consulting the list of contents on the first page of the chapter. For example, the
cylinder liner is part of the basic engine, therefore, it will be found in Chapter 2. Looking down the list of contents on the
first page of Chapter 2, the cylinder liner is found on page 10-2-92. Figure numbers are found in numerical order
beginning with Fig. 1 at the start of each new sub-heading. For instance, in Chapter 2, the first sub-heading is "Cylinder
Block" and Figure I is an illustration of a typical cylinder block. The second sub-heading in Chapter 2 is "Cylinder Block
End Plates," with Figure 1 being an illustration of the drain passages in the cylinder block.
SERVICE PARTS AVAILABILITY
Genuine Detroit Diesel Allison service parts are available from authorized Detroit Diesel Allison distributors and service
dealers throughout the world. A complete list of all distributors and dealers is available in the World Wide Parts and
Service Directory, 6SE280. This publication can be ordered from any authorized distributor.
CLEARANCES AND TORQUE SPECIFICATIONS
Clearances of new parts and wear limits on used parts are listed in tabular form at the end of each section throughout the
manual. It should be specifically noted that the "New Parts" clearances apply only when all new parts are used at the
point where the various specifications apply. This also applies to references within the text of the manual. The column
entitled "Limits" lists the amount of wear or increase in clearance which can be tolerated in used engine parts and still
assure satisfactory performance. It should be emphasized that the figures given as "Limits" must be qualified by the
judgment of personnel responsible for installing new parts. These wear limits are, in general, listed only for the parts
more frequently replaced in engine overhaul work. For additional information, refer to the paragraph entitled Inspection
under General Procedures in this chapter.
Bolt, nut and stud torque specifications are also listed in tabular form at the end of each chapter.