(9) Remove spring (19) and plunger (20) of
bypass valve from rear body (22).
Do not remove bearings
unless
(10) Remove bolt (7), tube (8), lock (6) and
replacement is required.
adapter (9) from front body (5).
(11) Remove bolts (15 and 21), locks (14), and
(16) Press bearings (37, 23, 30, and 2) out of
rear body (22) from front body (5).
bodies (5 and 22) as required, then remove pins (31 and
(12) Pull gears (24 and 38) from shafts (10 and
34) from body (5).
35), then remove spacer (25).
(13) Pull gear (1) from shaft (3) and remove
b. Cleaning, Inspection, and Repair.
Clean,
dowel (4).
inspect, and repair in a manner similar to that described
(14) Remove nut (26) and washer (27), then
in paragraph 3-45c above.
pull gear (29) from shaft (10).
(15) Remove gears (11 and 12) and shafts (10
c. Reassembly and Installation. Reassemble and
and 35) from front body (5), then separate gears from
install by reversing the procedures in steps (1) through
shafts. Remove keys (36) from shafts.
(16) of a above.
NOTE
Section XIII. ENGINE FRONT COVER (MODEL 687C-18-ES)
(10) Remove nut (16, fig. 3-53), lockwasher
3-47. General
(17), and capscrew (19), then remove engine support
(18) from crankshaft.
The front cover of engine model 687C-18-ES is an
(11) Remove fan support bracket (para 3-24).
aluminum casting mounted on front of crankcase. It
(12) Remove capscrews (9, 10, and 21, fig. 3-
contains oil and water passages, and serves as a mount
53)lockwashers (8), flatwashers (7), cover (6), and
for the overspeed governor and fan drive. The front end
gasket (4) from engine.
of the crankshaft is machined and extends through the
(13) Remove two nuts (14), lockwashers (8),
front cover oil seal to accommodate the fan drive sheave
flange (12), and gasket (11) from cover (6).
and vibration damper.
(14) Remove and discard seal (20) from cover
(6).
3-48.
Engine Front Cover Front Support, and
(15) Remove fan support dowel (18) and studs
Vibration Damper (Model 687C-18-ES)
(15) from cover (6).
(16) Reassemble and install front cover by
a. Removal and Disassembly.
reversing the procedures in steps (1) through (15) above.
(1) Remove engine (para 2-9).
(2) Remove fan (TM 5-3810-201-12).
b. Cleaning, Inspection, and Repair.
(3) Remove overspeed governor (TM 5-3810-
201-12).
(1) Clean all parts and dry thoroughly before
(4) Remove generator drive belt (TM 5-3810-
inspection or reassembly.
201-12).
(2) Inspect machined mating surfaces of
(5) Remove oil strainer (TM 5-3810-201-12).
engine crankcase and front cover, for pitting, corrosion,
(6) Remove oil pan (para 3-43).
or other damage. Assure that all gasket residue has
(7) Position wood blocks that are strong
been removed from mating surfaces of engine and front
enough to support engine weight, under forward end of
cover. Inspect all mounting hardware, and threaded
crankcase.
areas of cover for burs, or other damage. Inspect front
(8) Cut lockwire and remove drilled head
cover for breaks and cracks.
capscrew and retainer washer from fan drive sheave.
(3) Repair by replacing a defective cover.
(9) Install one capscrew in end of crankshaft
Replace all damaged mounting hardware. Replace all
as a guide, then install a puller and remove fan drive
gaskets and seals.
sheave.
AGO 20051A
3-63
