Rack and gear assembly.

TM 10-3930-634-34

As the nut is being tightened by hand, the spray tip

(7) Place the dry part on a third lapping block. Do

should become difficult to turn until eventually the

not use lapping powder on this block. Keep the part

spray tip will not turn. This insures the proper seating

flat and move it across the block several times in a

of components and nut being installed properly.

figure eight motion. Lapping the dry part in this

manner gives it the "mirror" finish required for per-

(g) Use a socket and torque wrench and tighten

nut to 75-80 lb-ft. of torque.

fect sealing.

NOTE

(8) Wash all of the lapped injector parts in clean

Do not exceed the specified torque. Other-

fuel oil and dry with compressed air.

wise, the nut may be stretched and result in

g. Reassembly.

improper sealing of the lapped surfaces in the

(1) Filter assembly.

injector.

(a) Use new filter and gaskets, and reassemble

(4) Plunger and follower.

the filter assembly on the injector as illustrated in

(a) Push the control rack all the way in.

figure 3-40.

(b) Slide the head of the plunger into the fol-

NOTE

lower and place the follower spring on the injector

The fuel filter has a dimple at one end. When

body.

assembling the filter always install the filter

(c) Place the stop pin on the injector body so

with the dimple end down.

that the follower spring rests on the narrow flange of

(b) Lubricate the filter cap (1, fig. 3-40) threads

the stop pin (fig. 3-35). Then aline the slot in the fol-

and tighten to 65-70 lb-ft. of torque. Install shipping

lower with the stop pin hole in the injector body. Aline

caps on all openings to prevent any dirt particles from

the flat side of the plunger with the slot in the

entering injector.

follower. Insert the free end of the plunger in the

(2) Rack and gear assembly.

injector body. Press down on the follower and at the

(a) Hold the injector body (10, fig. 3-50),

same time press the stop pin into position. When in

bottom end up, and slide the rack (8) through the hole

place, the spring will hold the stop pin in position.

in the body. Look into the bore of the body, for the

h. Installation.

gear teeth on the rack, move rack so that the drill

(1) Prior to installing the fuel injector perform all

marks can be observed and hold the rack in this

the tests listed in c above.

position.

(2) Before installing the fuel injector wipe carbon

(b) Slide gear (9), into the injector body so that

deposits from the beveled seat in the injector tube. Use

the marked tooth is engaged between the two marked

care to prevent entry of foreign material into the en-

teeth on the rack as shown in figure 3-50.

gine.

(c) Place the gear retainer (7) on the gear. Next,

(3) Use the injector tube bevel reamer to clean

aline the locating pin in the bushing (1 1), with the slot

carbon from injector tube. Exercise care to remove

in the injector body; then slide bushing into place.

only the carbon so that the proper clearance between

(3) Spiny tip, spring cage and check valve assem-

injector body and cylinder head is maintained. Pack

blies.

flutes of reamer with grease to retain carbon removed

(a) Position a new preformed packing (2, fig.

from injector tube.

3-50), on the shoulder of the body (10). Slide the spill

(4) Fill the injector with clean fuel oil until it runs

deflector (15), over the installed bushing (11).

out of the outlet cap.

(b) Place check valve (6), centrally on the

(5) Install the fuel injector (fig. 3-31) as follows:

bushing (11). Place valve cage (12), over the check

(a) Make sure the dowel pin in the injector body

valve (6) and against bushing (11).

is alined with the dowel hole in the cylinder head.

(c) Insert the spring seat (13), in spring (5). In-

(b) Position the injector rack control lever so the

sert this assembly into spring cage (4), spring seat

lower end of lever engages the injector rack.

first.

(c) Install the injector bracket and torque bolt to

(d) Place the assembled spring cage (4), spring

20-25 lb- ft. and recheck to make sure bracket does

seat (13) and spring (5) on the check valve cage (12),

not interfere with injector follower spring or exhaust

spring first.

valve spring.

(e) Insert needle valve (14), tapered end down,

NOTE

inside the spray tip (3). Place the spray tip with needle

Check the injector rack for free movement.

valve on the spring cage (4), with the small end of the

Excess torque can cause the injector control

needle valve in the hole in the spring cage.

rack to stick or bind.

(f) Lubricate the threads in the nut (1), and

CAUTION

carefully thread the nut on the injector body (10) by

There is a possibility of damaging the ex-

hand. Rotate the spray tip (3), between your thumb

haust valves if the exhaust valve bridge is not

and index finger while threading the nut on the body.

3-31