Rocker Arms and Push Rods - TM-10-3930-242-340075

TM 10-3930-242-34

haust valve when tightening rocker shaft

enough pressure to keep the part flat on the

bracket bolts. Note position of exhaust

block at all times. Do not lap excessively. When

valve bridge, before, during, and after

p a r t is flat, wash in cleaning solvent and dry

tightening the rocker shaft bracket bolts.

t h o r o u g h l y with compressed air.

( 4 ) Place dry part on second block; apply

(3) Move rocker arm assembly into position

l a p p i n g powder. Repeat action.

a n d tighten rocker arm bracket bolts.

(5) Place dry part on third block. Do not use

CAUTION

lapping powder on this block. Keep the part flat

Do not bend fuel pipes and do not exceed

a n d move across block several times using the

specified torque. Excessive torque will

figure eight motion. Lapping dry part in this

twist or fracture flared end of fuel line

m a n n e r gives the "mirror" finish required for

and result in leaks. Lubricating oil di-

p e r f e c t sealing. Wash all lapped parts in clean

luted by fuel oil can cause serious dam-

solvent and dry with clean, dry compressed air.

age to engine bearings.

h. Reassemble. Refer to figure 3-23,3-24, and

3 - 2 5 and reassemble the fuel injector.

(4) Remove shipping caps. Align the fuel

i. Spray Tip Concentricity Check.

p i p e s and connect them to the injector and fuel

(1) Place the injector in the concentricity

connectors.

gage (fig. 3-30).

k . Fuel Injector Timing.

( 2 ) Adjust the dial indicator to "O". Rotate

( 1 ) Place the speed control lever in idle

t h e injector 360 degrees and note the total run-

speed position. If a stop lever is provided, secure

out as indicated on dial. If total runout exceeds

it in no-fuel position.

0 . 0 0 8 inch, remove injector from gage. Loosen

CAUTION

i n j e c t o r nut, recenter spray tip, tighten the nut

If a wrench is used on crankshaft bolt at

t o 75-80 foot pounds torque, and recheck con-

the front of engine, do not turn crank-

centricity.

shaft in a left-hand direction of rotation

j . Installation. Before installing an injector in

or the bolt will be loosened.

a n engine, remove carbon deposits from the be-

veled seat of injector tube in the cylinder head.

(2) Rotate the crankshaft, manually or with

T h i s will assure correct alignment of injector

t h e starter, until the exhaust valves are fully

a n d prevent any undue stress from being emp-

depressed on the particular cylinder to be timed.

l o y e d against the spray tip. Use the injector

( 3 ) Place small end of the injector timing

t u b e bevel reamer to clean carbon from injector

g a g e in hole provided in top of injector body,

tube. Exercise care to remove only the carbon so

w i t h flat of gage toward injector.

t h a t the proper clearance between the injector

(4) Loosen push rod locknut.

b o d y and cylinder head is maintained, Pack the

( 5 ) Turn the push rod and adjust the injec-

f l u t e s of reamer with grease to retain carbon

t o r rocker arm until the extended part of gage

removed from tube. Install fuel injectors as fol-

will just pass over top of injector follower.

lows:

(6) Hold push rod and tighten locknut.

(1) Refer to figure 3-20 to install in fuel in-

C h e c k the adjustment and readjust, if neces-

jector. Be sure the dowel pin in the injector body

sary.

r e g i s t e r s with the dowel pin hole in the head,

( 7 ) Time the remaining injectors, as out-

Position injector rack control lever so the lower

l i n e d above.

e n d of lever engages injector rack.

(8) Use new gaskets and install valve rocker

( 2 ) Install the injector bracket and torque

cover (TM 10-3930-242-12).

b o l t to 20-25 foot pounds and recheck to make

3-15. Rocker Arms and Push Rods

sure bracket does not interfere with inject or fol-

a. General. Located in the cylinder head are

l o w e r spring or exhaust valve spring.

the exhaust valves, fuel injectors, and three

NOTE

r o c k e r arms for each cylinder. One rocker arm

Cheek the injector rack for free movement. Ex-

operates. the injector plunger; the other two op-

cess torque can cause the injector control rack to

e r a t e the exhaust valves. The rocker arms are

stick or bind,

o p e r a t e d by the camshaft through cam follow-

CAUTION

e r s and push rods.

There is a possibility of damaging the

b. Removal.

exhaust valves if the exhaust valve

(1) Remove rocker arm cover (TM

bridge is not resting on the ends of ex-

10-3930-242-12).

3-35