Figure3-21. measuring motor lobe to housing clearance

TM 1O-393O-634-34

( 4 ) Inspect the rotor shaft, gear and drive

(1) Clean the blower assembly components, using

coupling for burred or worn condition. Remove burrs

a dry cleaning solvent such as P-D-680 or equal.

with crocus cloth. Replace parts that are worn.

(2) Inspect the finished inside face of the end

(5) Inspect blower gears for excessive wear or

plates. Slight scoring may be cleaned with crocus

damage. Replace as necessary.

cloth. If the surface is badly scored, replace the end

(6) Inspect the bearing and oil seal contact sur-

plate.

faces of the rotor shafts and end plates for scoring

(3) Inspect the surface of the rotors and the

wear or nicks. Replace as necessary.

blower housing. Remove burrs and scratches with an

NOTE

oil stone.

Loose rotor shafts or worn rotor shaft pilot

bearings will result in contact between the

rotors and end plates or between rotor lobes

and housing. Excessive backlash between

gears usually results in rotor lobes rubbing to-

gether throughout their entire length. Refer

to table 1-1 for wear limits and replacement

standards.

3-22