Section XV. Repair of Rocker Arm Assembly and Push Rods

*TM 9-2815-213-34

at each of remaining positions shown above (16 and

NOTE

6.0 BTC). If push rod travel is greater or le than

Before installing new key, make sure

limits shown, timing is slow or fast respectively. A

guide spring on tappet body is not hold-

new camshaft key must be installed bring push rod

ing tappet off camshaft lobe.

travel within limits. Refer to paragraph 212.k. for

removal of shaft, and pal graph 3-30 for disassembly.

i. Recheck limits as outlined in Chart 3-1.

j. Remove timing fixture and injector push rod.

Section XV. Repair of Rocker Arm Assembly and Push Rods

3-80. Disassembly

gage or by observation of small protrusion at the

(fig. B-6)

bottom of socket.

a. Remove locating socket head stew (44)

(6) Check that all lubricating oil passages

from mounting bracket (8). The rocker shaft locating

are open.

socket head screws are located on rear left bank and

(7) Inspect thread condition on all screws and rocker

front of right bank assemblies.

arms. Check closely for thread dam- age at assembled

b. Slide rocker arm shaft brackets and rock

position of locknut. Ensure

arms (47, 50, and 52) from the shaft (46).

that screws operate freely through rocker arms.

c. Remove rocker arm shaft plugs (45) from

(8) Check rocker arm shaft for scoring, galling, out-

each end of each shaft.

of-round and wear. If worn smaller than 1.1845 inches,

d. Remove adjusting screws (55) and

install new shaft.

locknut

(54) from rocker arms.

NOTE

New rocker arm shaft measures 1.1856/

3.81. Cleaning

1.1865 inches with a wear limit to 1.1845

Clean all parts in accordance with paragraph 2

inches,

3-82. Inspection

(9) Examine rocker arm shaft brackets for cracks,

a. Rocker Arm Assembly

breaks and stripped threads. Replace as necessary.

(1) Perform general inspection of rocker arm

(10) Visually inspect arm side surfaces which mate

assembly in accordance with paragraph 2-8

with adjacent arms. If galled, grind surfaces to original

(2) Gage rocker lever bushings with tele

smoothness.

scope gage and micrometer.

b. Push Rods.

(a) Set telescopic gage 0.0002 inch above

(1) Check ball end of all push rods for worn radii. A

worn limit of 1.1905 inches for use as a plug gage.

new allowance of 0.3150 inch. Check in- jector and valve

push rod ball ends with 5/16 inch radius gage.

NOTE

(2) Test sockets of push rods with ball end of a new

The inside diameter of a new rocker arm

rocker lever adjusting screw or with 1/4 inch fillet gage.

bushing is 1.1875/1.1895 inches and may

(3) Replace defective push rods. Extreme wear on

wear to 1.1905 inches maximum.

either end of push rod will result in loss of lubricating oil

pressure and may interfere with proper injector and valve

(b) Replace bushings worn beyond limits

adjustment.

(para. d, below).

(3) Check intake and exhaust rocker arm

3-83. Repair

crosshead contact surface. If worn or damaged,

Repair of the rocker arm assembly and push rods is limited

replace with new rocker arm.

to replacement of defective parts. Re- place rocker arm

(4) The ball end of rocker arm adjusting

bushing as follows:

screws must be true spheres. Test with 1/4 inch

a. Press out worn bushing with mandrel and

radius gage and replace worn adjusting screw

block set (4, fig. B-28).

(5) Worn injector rocker arm sockets must

be replaced. Wear is easily detected with fillet

3-34