Opel 1900 1973 Service Manual page 35

6. Remove shift lever shaft and: lift armature aid
shift lever assembly.
7. Drive back retaining ring on armature shaft. See
Figure lB-5.
8. Take the lock ring, retaining ring, and over&-
ning clutch and pinion off armature shaft. Cheqk
groove in shaft for burrs and remove with a soft tile.
Cleaning and Inspecting Parts
2. Turn down worn or burnt cominutator on a good
precision lathe. Use a spindle speed between 2,000
and 3,000 RPM. See Figure lB-6. When turning
down commutator, adjust cutting depth of tool so
that no more pits exist after this:operation. Do not
remove any more material than necessary, however,
because if commutator diameter is less than 1 15/32
inches, armature must be replaced.
Figure 1B-6 Turning Down Commutator
3. Undercut mica approximately ,020 below com-
mutator surface. Finish and thoroughly clean corn-
4. Check armature for short circuit on a growler.
5. With a test lamp, check armature for ground. Test
lamp must not light up. See Figure IB-7.
Figure 1B-7 Testing Armature for Grounds
6. Check armature for an open circuit on a growler.
Considerable variation in readings between in-
dividual commutator bars would indicate an open
circuit.
7. Visually check
scorched field coils.
8. With a test lamp, check field coils for ground. See
Figure IB-8. Test lamp must not light up. Replzice
grounded field coil.
3 0 1 6 6
Figure lB-8 Checking Field Coils for Ground
Replacing Field Coils
1. Mark locations of pole shoes to avoid incorrect
installation.
Figure 1B-9 Removing Pole Shoes
coils. Replace burnt or