TM-9-2815-200-35
ENGINE, WITH CONTAINER:TURBOSUPERCHARGED, DIESEL ,FUEL INJECTION ,90-DEGREE “V” TYPE, AIR - COOLED ,12 - CYLINDER , ASSEMBLY ;MODELS AVDS-1790-2M (2815-856-4996), AVDS-1790-2A AND AVDS-1790-2AM (2815-856-9005)
TECHNICAL MANUAL; DIRECT SUPPORT, GENERAL SUPPORT AND DEPOT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS
TM-9-2815-200-35 - Page 367 of 779
g.
Valve Rocker Arm Covers .
(1) Repair or replace damaged parts .
Welding is permissible on the two valve rocker
arm shaft plug bosses on the outside of the cover.
Welding in other areas of the cover is
not
per -
missible. Refer to paragraph 6-4c for general
welding instructions, and paragraph (e), below.
(a) Replace cylinder assembly when
valve rocker arm cover is cracked (except at the
rocket arm shaft plug boss which can be welded),
or has deep scratches or nicks on the mating
surface or camshaft bearing bore surface .
Replace cylinder when cover damage cannot be
removed by polishing with crocus cloth dipped in
dry-cleaning solvent or mineral spirits paint
thinner.
(b) Replace cylinder assembly when valve
rocker cover does not conform to limits specified
in the overhaul standards (table 6-15).
(c) Replace damaged screw thread inserts
as instructed in paragraph 6-5.
(d) Replace cracked adjusting cove r
plates. Remove minor nicks, burs, or scratches
from mating surface with crocus cloth dipped in
dry-cleaning solvent or mineral spirits paint
thinner.
(e) Covers that have been repaired by
welding must meet the requirements specified in
figure 6-64.
Figure 6-64.
Valve rocker arm cover welding standards.
AT 311
h. Valve Rocker Arm.
(Refer to fig. B-4)
(1) Replace valve rocker arms (33 and 34)
when cracked or worn or if the bushing-type
bearings are damaged.
(2) Replace damaged valve rocker ar m
roller and bushing.
(3) Replace adjusting screw (36) when
threads are stripped or damaged or when screw
binds in rocker arm. Replace adjusting screw
when swivel pad does not rotate freely on screw.
i. Valve Rocker Arm Shaft Assemblies .
(Refer to fig. B-4)
77
(1) Replace cracked or deeply scored rocker
arm shaft assemblies (22 and 35).
(2) Replace rocker arm shafts that do not
conform to limits specified in the overhau l
standards (table 6-15).
Valve, Springs,
Spring Retainers an d
Rotors.
(Refer to fig. B-4)
(1)
Valves.
(a) Discard warped valves (11 and 12) or
valves which do not conform to limits specified in
repair and, rebuild standards (table 6-1 5) .
Discard valves having badly pitted or burned
6-7 3
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