Piper Arrow IV Turbo Maintenance Manual page 682

Figure 80-5. No-Load Test Hook-up
ASSEMBLY OF STARTING MOTOR.
1. When assembling the starting motor, always use an arbor press and the proper bearing arbor for
installing graphitized bronze and roller bearings. The Bendix shaft should have a thin film of Lubriplate #777
or equivalent on the Bendix portion of the shaft. End play should be .005 to .050 of an inch.
2. New brushes should be properly seated when installing by wrapping a strip of 00 sandpaper around the
commutator (with the sanding side out) 1-1/4 to 1-1/2 times maximum. Drop brushes on sandpaper covered
commutator and turn the armature slowly in the direction of rotation. Dust should be blown out of the motor
after sanding.
The spring tension is 32 to 40 ounces with new brushes. This
tension is measured with the scale hooked under the brush spring
near the brush and the reading is taken at right angles to the line
of force exerted by the brush spring.
3. Check the position of the pinion to be sure the unit will mesh properly with the flywheel ring gear. See
specifications for unit for correct dimensions. (Refer to Starting Motor Service Test Specifications.)
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL
Figure 80-6. Stall-Torque Hook-up
—NOTE—
3G19
80-10-11
Page 80-08
December 1, 1978