Engine Blower Assembly

( 3 ) Check for oil leaks,

3-5. Engine Blower Assembly

(4) Check for loose or worn shaft bearings,

a. G e n e r a l . The blower assembly supplies fresh

Refer

table

1-1

for

replacement

standards.

air required for combustion and scavenging. The

revolving motion of the rotor provides a continuous

NOTE

and uniform displacement of air.

Loose rotor shafts or worn rotor shaft bearings will

result in contact between rotor lobes, rotor and end

b. Removal.

plates or rotor and housing. Excessive backlash be-

NOTE

tween blower timing gears usually results in rotor

The blower and governor are bolted together and

lobes rubbing together throughout their entire length.

must be removed as an assembly (fig. 3-8).

e. Reassembly. Refer to figure 3-10 and

(1) Remove the air inlet housing (fig. 3-6).

reassemble the blower assembly as follows:

( 2 ) Disconnect the linkage from the governor

(1) Lubricate the oil seals (27) with clean

control levers.

e n g i n e oil and place a seal in each front end plate

(3) Remove the screws and lock washers which

(26) counterbore.

a t t a c h the governor cover to the governor housing.

(2) Place the front end plate on two wood

Remove the cover and gasket from the housing.

b l o c k s . Install the rotors, gear end up, on the end

( 4 ) Remove two bolts and lock washers which

plate.

hold the spring housing (3, fig. 3-14) to the

( 3 ) Install two oil seals (34) in the rear end

governor housing. Remove spring housing and

plate (33) as outlined in step 1.

gasket.

(4) Place the rear end plate over the rotor

(5) Remove spring assembly from the

shafts. Be sure that seals are properly positioned on

governor.

rotors. Secure end plates to blower housing with

(6) Loosen the hose clamps and slide the hoses

bolts (l).

b a c k on the fuel rod covers.

NOTE

(7) Remove the rocker arm cover from each

To prevent inadequate lubrication or low oil pressure,

cylinder head.

care must be exercised in assembly of front and rear

(8) Disconnect the lower fuel rod from each

blower end plates to blower housing. The rear end

injector control tube lever and also from each upper

plate does not have tapped holes for the thrust washer

fuel rod.

plate bolts and is the only cover that has the vertical

oil passage drilled through into the pocket on left side

( 9 ) Remove the threaded pins connecting the

of end plate for supplying lubrication to the blower

fuel rods to the control link lever. Remove the

drive gear bearing.

upper fuel rods.

(10) Remove the blower drive cover plate.

(5) Attach two thrust washers (24) to front

Remove the snap ring and withdraw the blower

end of the blower with thrust washer retaining bolts

drive shaft from the housing (fig. 3-9).

(23). Refer to paragraph 1-4 r for proper torque.

(11) Remove the two bolts and copper washers

( 6 ) Attach three spacers (25) and thrust plate

h o l d i n g the blower drive support assembly. Then,

(22) to the front end of blower with three t h r u s t

w i t h d r a w the assembly until the splined end of the

plate bolts (21). Tighten the bolts to 7-9 foot-

d r i v e shaft is free from the drive plate. Turn the

p o u n d s torque . Check the clearance between thrust

d r i v e assembly slightly so the serrated end of the

plate and thrust washer. Refer to table 1-1.

governor weight shaft will pass around the governor

(7) Position the rotors so that the missing

operating fork. Remove the blower drive support

s e r r a t i o n s on the gear end of rotor shafts are 90

from the engine.

apart. This is accomplished by placing the rotors

c . D i s a s s e m b l y . Refer to figure 3-10 and

w i t h missing serration in the upper rotor facing to

disassemble the blower assembly as follows:

the left, and missing serration in the lower rotor

(1) Wedge a clean cloth between the blower

facing the bottom. Install shims (19) and spacers

rotors to prevent their turning and remove four

( 2 0 ) in counterbore in the rear face of rotor gears.

bolts (6) that hold the blower drive cam retainer (7)

P l a c e the gears on ends of the shafts with missing

a n d blower drive spring support (9) to rotor gear.

s e r r a t i o n s in alignment with missing serrations on

(2) Use two pullers to remove both blower

the shafts.

g e a r s from the rotor shaft at the same time. Mark

(8) Tap gears lightly with a soft hammer to

t h e left-hand rotor gear to facilitate identification

seat gears on the shaft. Rotate gears until the punch

at reassembly.

marks on the fate of the gears match. If punch

d. Inspection.

marks do not match, reposition gears.

(1) Inspect rotors and housing for burrs or

(9) Wedge a clean cloth between blower rotors.

scratches. If burrs or scratches exist, dress the parts

Use the blower rotor gear retaining bolts and plain

d o w n with an oil stone.

washers to press gears on the rotor shafts. Turn

(2) Inspect rotors for scoring.

3-8