3. Refer to Fig. 7 and affix a new gasket (32) to the
d. Install the second ball bearing on the remaining
blower front end plate cover (28).
rotor shaft in the same manner.
4. Position the end plate cover over the end plate dowel
e. Place the bearing retainers on top of the
pins, with the large hole in the cover toward the top of
bearings and the end plate; then, install the
the end plate, then push the cover against the end plate.
retainer bolts and lock washers. Tighten the
Install the ten bolts and lock washers. Tighten the bolts
bolts to 7-9 lb-ft (9-12 Nm) torque.
to 13-17 lb-ft (18-23 Nm) torque.
5. Install the ball bearings on the rotor shafts and in the
6. Make a preliminary check of the rotor-to-end plate
rear end plate as follows:
and rotor-to-housing clearances at this time with a feeler
a. Reverse the position of the blower housing on
minimum blower clearances.
7. Install the blower rotor timing gears as follows:
b. Lubricate one of the ball bearings with engine
oil. Start the bearing numbered end up, straight
One serration is omitted on the drive end of each blower
on one of the rotor shafts.
rotor shaft and a corresponding serration is omitted in
each gear. Assemble the gears on the rotor shafts with
the serrations in alignment.
A center punch mark placed in the end of each rotor
shaft at the omitted serrations will assist in aligning the
gears on the shafts.
a. Place the blower housing and rotor assembly on
the bench with the air inlet side of the housing
facing up and the rear end (serrated end of rotor
shafts) of the blower facing the outside of the
b. Rotate the rotors to bring the omitted serrations
on the shafts in alignment and facing the top of
c. Install the same number and thickness of shims
on the rotor shafts that were removed at the
time of disassembly.
When rebuilding a blower with new
rotors or new gears, first install the
gears on the rotor shafts without the
shims, then check the clearances
between the rotors to determine the
location and thickness of shims to
d. Lubricate the serrations of the rotor shafts with
e. Place the teeth of the rotor gears in mesh so
Fig. 14 - Installing Ball Bearing on Rotor Shaft and
that the omitted serrations inside the gears are
in Rear End Plate using Tool J 6270-7.
in alignment and facing the same direction as
c. Place installer J 6270-7 on top of the bearing
the serrations on the shafts.
and tap the bearing straight on the shaft and
into the rear end plate as shown in Fig. 14.