8-12 POWER TRIM AND TILT
PTT MOTOR INSPECTION
Armature and Commutator
1. Inspect the commutator surface for gum or dirt.
Clean with #500 grit emery paper if necessary.
Measure the commutator outside diameter.
$
09900-20101: Vernier calipers
Commutator outside diameter:
Standard
: 22.0 mm (0.87 in)
Service limit: 21.0 mm (0.83 in)
If the measurement exceeds the service limit, replace the arma-
ture.
2. Measure the commutator undercut (depth) between the mica
(insulator) and the segments.
Commutator undercut
1
1
1
1
1
(depth):
Standard
: 1.6 – 1.9 mm (0.06 – 0.07 in)
Service limit: 1.3 mm (0.05 in)
If the measurement exceeds the service limit, cut the mica to
the specified depth.
NOTE:
Remove all particles of the mica and the metal using compressed
air.
#
Wear safety grasses when using compressed air.
$
$
3. Inspect the continuity between the commutator and the ar-
mature core/shaft.
If the continuity exists, replace the armature.
$
09930-99320: Digital tester
%
Tester range:
&
&
&
&
&
(Continuity)
4. Inspect the continuity between the adjacent commutator seg-
ments.
If no continuity exists, replace the armature.
SEGMENT
MICA
Commutator undercut