Excessive backlash between the blower rotor gears usually results in the rotor lobes rubbing throughout their
Before removing the blower from the engine, remove the air shutdown housing as outlined in Air Shutdown
1. Loosen the clamp retaining the cover-to-support seal.
2. Remove the four blower-to-block bolts and special washers and lift the blower away from the engine, being
careful not to damage the serrations on the blower drive shaft.
Figure 2. Removing Blower Rotor Gears
1. Refer to Fig. 3 and remove the six bolts, special washers, and reinforcement plates which secure the front
end plate cover and the front- end plate to the blower housing. Then remove the end plate cover and gasket
from the end plate.
2. Remove the six bolts, special washers, and reinforcement plates which secure the rear end plate cover and
the rear end plate to the blower housing. Then remove the end plate cover and gasket from the end plate.
3. Wedge a clean cloth between the rotors to prevent their turning and remove the four bolts that hold the
blower drive cam retainer and blower drive spring support to the gear. Separate the retainer, support, and
spacer from the gear.
4. Remove the retaining bolts and the washer and the blower drive cam pilot from the blower gears.
5. For identification, mark the upper gear on the blower.
6. Use two pullers J 24420 to remove
the two gears simultaneously.
7. Remove the rotor shims and the gear spacers and place them with their respective gears to ensure correct
8. At the other end of the blower, remove the three thrust plate bolts, the thrust plate and three spacers from
the front end plate. Remove the bolts and thrust washers.
9. Tap the end plate off of the dowel pins and housing with a soft (plastic) hammer, being careful not to
damage the mating surfaces of the end plate and the housing.