DETROIT DIESEL 53
rust preventive compound should be removed before
installing the parts in an engine.
If parts are not to be used immediately after cleaning,
dip them in a suitable rust preventive compound. The
The purpose of parts inspection is to determine which
Many service replacement parts are available in
parts can be used and which must be replaced.
various undersize and/or oversize as well as standard
Although the engine overhaul specifications given
sizes. Also, service kits for reconditioning certain parts
throughout the text will aid in determining which parts
and service sets which include all of the parts
should be replaced, considerable judgment must be
necessary to complete a particular repair job are
exercised by the inspector.
The guiding factors in determining the usability of
A complete discussion of the proper methods of
worn parts, which are otherwise in good condition, is
precision measuring and inspection are outside the
the clearance between the mating parts and the rate of
scope of this manual. However, every shop should be
wear on each of the parts. If it is determined that the
equipped with standard gages, such as dial bore gages,
rate of wear will maintain the clearances within the
specified maximum allowable until the next overhaul
period, the reinstallation of used parts may be
justified. Rate of wear of a part is determined by
In addition to measuring the used parts after cleaning,
dividing the amount the part has worn by the hours it
the parts should be carefully inspected for cracks,
scoring, chipping and other defects.
Following cleaning and inspection, the engine should
possible, be located away from the disassembly and
be assembled using new parts as determined by the
cleaning operation. Also, any machining operations
should be removed as far as possible from the
Use of the proper equipment and tools makes the job
progress faster and produces better results. Likewise, a
Particular attention should be paid to storing of parts
suitable working space with proper lighting must be
and sub-assemblies, after removal and cleaning and
provided. The time and money invested in providing
prior to assembly, in such a place or manner as to
the proper tools, equipment and space will be repaid
keep them clean. If there is any doubt as to the
cleanliness of such parts, they should be recleaned.
Keep the working space, the equipment, tools and
When assembling an engine or any part thereof, refer
engine assemblies and parts clean at all times. The
to the table of torque specifications at the end of each
area where assembly operations take place should, if
section for proper bolt, nut and stud torques.
A serviceman can be severely injured if caught in the
position. This will mean the governor is in the no-
pulleys, belts or fan of an engine that is accidentally
fuel position. The possibility of the engine firing
started. To avoid such a misfortune, take these
by accidentally turning the fan or, in the case of
precautions before starting to work on an engine:
vehicle application, by being bumped by another
vehicle is minimized.
Disconnect the battery from the starting system by
removing one or both of the battery cables. With
Some Safety Precautions To Observe When
the electrical circuit disrupted, accidental contact
Working On The Engine
with the starter button will not produce an engine
1. Consider the hazards of the job and wear protective
Make sure the mechanism provided at the
gear such as safety glasses, safety shoes. hard hat, etc.
governor for stopping the engine is in the stop
to provide adequate protection.