ARMY TM 9-2815-253-24
AIR FORCE TO 38G1-93-2
MARINE CORPS TM 2815-24/3
SECTION III. GENERAL MAINTENANCE
This section provides general maintenance not found in other sections of Chapter 3.
3-3.1. General Instructions.
Where applicable, prior to performing engine maintenance, ensure batteries are disconnected.
Failure to observe this warning could result in personal Injury.
Refer to end item maintenance manual for removal of any components necessary to gain access to
It is strongly recommended that bolts or nuts securing cylinder heads, covers, and doors be tightened in proper
When assembling an engine, it is always advisable to replace nuts, bolts, and lockwashers that have been
removed from high stress locations, in particular nuts and/or bolts from connecting rods and cylinder heads
should be replaced.
When assembling an engine it is always advisable to apply a small quantity of new lubricating oil to all moving
parts. After any maintenance work on engine has been completed lubricating oil and fuel levels must be
checked and all safety guards installed before operating.
When a new fan drive belt has been installed, check belt tension after first 20 hours of operation.
Wear protective overalls, and keep items of loose clothing clear of all hot and moving parts.
Whenever possible, clean components and surrounding area before removing or disassembling. Take care to
exclude all dirt and debris from fuel injection equipment while it is being serviced.
Some parts are cemented with gasket compound with others being dry. Before assembly, remove all traces of
old gasket and compound. Take extreme care to exclude dirt from all gasket surfaces and gasket compound
from all tapped holes unless otherwise specified.
It is recommended that all oil seals are replaced once they have been removed from their original position.
Seals must be installed square in housing and all lip seals must be installed with lip facing lubricant to be
A service tool should be used to install all oil seals and care must be taken to prevent damaging new seal when it
passes over shafts.
Replace all nuts, bolts, capscrews and studs with damaged threads. Do not use a tap or die to repair damaged
threads which may impair the strength and closeness of the threads and is not recommended.
Do not allow grease or oil to enter a blind threaded hole as hydraulic action present when bolt or stud is screwed
in could split or stress housing.
To check or retorque a bolt or nut, item is slackened a quarter of a turn and then tightened to specified value.
A steel ISO metric bolt, capscrew or nut can be identified by the letter M either on head or one hexagon flat.
The strength grade will also be marked on top or one flat.
On nuts with identification marks on one face the frictional area of that surface will be reduced, therefore nut
should be installed with unmarked face towards component.
Service tools are designed to aid disassembly and assembly procedures and their use will prevent possible
unnecessary damage to components. It is recommended that service tools are always used, some operations
cannot be safely carried out without aid of relevant tool.
When removing/disconnecting fuel or lubrication lines and coolant hoses cap/cover all openings to prevent entry
of foreign material.