REPAIR OF CRANE ENGINE
Section I. GENERAL
The crane engine is a 4-cylinder, in-line, Detroit Diesel Series 53 engine.
4-2. Engine Removal
Refer to paragraph 2-12 and remove the engine from the crane. Install the engine on a suitable stand for ease of
4-3. Removal of Accessories
a Refer to TM 5-3810-295-12 and chapter 3 of this manual and remove the following accessories from the engine.
(1) Oil filters and lines.
(2) Oil cooler.
(4) Starting motor.
(5) Water pump.
(6) Air inlet housing.
(7) Air blower.
(8) Fuel pump and fuel lines.
(9) Engine governor.
b Parts removed from the engine should be stored together so they will be available for reassembly. Items that have
machined faces, which could be damaged, should be stored on Wooden blocks, racks or parts dolly.
Section II. CYLINDER HEAD, ROCKER ARMS AND VALVES
The cylinder head is a one-piece casting, bolt mounted on top of the cylinder block. The cylinder head may be removed as
a single assembly containing the cam followers, cam follower guides, rocker arms, exhaust valves, and injectors.
a. Refer to figure 4-1. Remove exhaust manifold by removing nuts (1), washers (2), manifold (3) and gasket (4).
Remove pipe plug (5) from the manifold.
b Remove rocker arm cover screws (6), cover (7) and gasket (8). Refer to paragraph 3-62 and disconnect and
remove injector controls, bracket and fuel rod.
c Remove fuel pipes (9), adapter (10) and adapter washers (11). Cover fuel openings in the fuel manifold and
injectors to prevent dirt and foreign material from entering the fuel system.
d Crank the engine to bring the outer ends of the push rods on the injector and valve rocker arms in line horizontally.
Remove rocker arm shaft bracket bolts (12) and swing the rocker arms away from the injector and valves.
e Remove injector clamp screws (13), washers (14) and clamps (15). Remove injector. (16).
f Remove cylinder head bolts (17). Install lifting brackets and remove head from the cylinder head on the work
bench, be sure to protect the cam follower rollers and the injector spray tips by resting the valve side of the head on -inch-
thick blocks of wood.
a Refer to figure 4-1. Remove gasket (18), compression gaske (19) from individual cylinders, and seal rings (20),
(21) and (22).
b Lift the rocker arm and bracket assemblies from the cylinder head. Loosen lock nut (23) and separate the push rod
assembly from the rocker arms.
c Remove retainer (24), spring seat (25), push rod spring (26), spring seat 7) and push rod (28).
d. Remove clevis pins (29), bushings (30) and (31), and clevis (32). Remove bridge pins (33) and bridges (34).
e Side shaft brackets (35) from shaft (41). Remove rocker arms (36), (37) and (38). Remove bushings (39) and
shaft plugs (40) from shaft (41).
f Compress springs (44) and remove lock halves (42). Remove caps (43), springs (44) and valve seats (45).
g Turn the cylinder head over and remove valves (46). Remove inserts (47) and guides (48).
Mark valves so that they can be installed in the same relative locations.
h Remove screws (49) and lock washers (50). Remove cam follower guides (51) and roles (52), and cam followers
(53) as an assembly. Disassemble by driving the roller pin from the guide.
i Press injector hole tube (54) from the cylinder head, pressing from the bottom of the head. Remove injector hole
seal ring (55).