100—ELECTRICAL SYSTEM
CHRYSLER SERVICE MANUAL
b. Testing Armature for Ground
12. SERVICING THE BUSHINGS
Touch armature shaft and end of a commutator bar with pair of test lamp test prods. If lamp lights, it indicates a grounded armature. Replace grounded armature.
Inspect armature shaft bearing surfaces and bearings for wear by placing core in vise equipped with soft jaws. Do not squeeze tightly. Try commutator end frame, the drive end frame, and armature support bearings for wear by placing them on shafts and checking for side play. Replace commutator end frame assembly if bearing is worn. Also, replace drive end bearing if it is worn. The bearing should be well soaked in SAE 10-W Engine Oil before it is installed.
c. Testing Commutator Run-Out, Refacing and Undercutting Place armature in pair of "Vee" blocks and check runout with dial indicator. Check both shaft and commutator. A bent shaft requires replacement of armature. When commutator runout exceeds .003 inch, commutator should be refaced. Remove only sufficient metal to provide a smooth, even surface. After commutator is refaced, undercut insulation between bars to depth of Ys2 inch with a thin, hacksaw blade, or Tool C-770. Undercut insulation square and full width of groove, and polish commutator with 00 sandpaper to remove burrs. 10. TESTING THE BRUSH HOLDERS AND FIELD COILS FOR GROUND Touch each of brush holders with a test lamp prod, while holding the other test prod against starter frame. Two of brush holders that are 180 degrees apart should cause test lamp to light, as they are intentionally grounded. The other two brush holders should not cause lamp to light when tested, as they are insulated. If these insulated brush holders cause lamp to light when tested, it indicates that brush holders or field coil are grounded. Be sure brush pigtails or leads are not touching field frame.
13. SERVICING THE DRIVE UNIT Place drive unit on shaft and, while holding armature, rotate pinion. The drive pinion should rotate smoothly in one direction (not necessarily easily), but should not rotate in opposite direction. If drive unit does not function properly or pinion is worn or burred, replace drive unit. 14. ASSEMBLING THE STARTER (Refer to Figure 4.) Assemble drive end parts on armature and slide assembly into field frame until end of commutator touches brushes. While holding armature against brushes with slight pressure, push brushes up and allow them to come to rest on commutator. When all brushes are seated on commutator, slide armature assembly into place. Install commutator end frames and through bolts. Make sure end frames are positioned on dowel pins, and tighten through bolts. Install solenoid switch assem-
Remove screws from field-coil-to-brush-holder leads and insulate leads from brush holders. Retest by first touching holders and then field coil leads. If field coils are grounded, inspect terminal insulation. If insulation is in good condition, test each coil separately after unsoldering connection wire. Replace grounded field coils. If brush holders are grounded, replace frame and brush holder assembly. 11. REPLACING THE FIELD COILS A pole shoe screwdriver should be used to remove and install field coils to prevent damage to pole shoe screws and for proper tightening. Pole shoes that are loose may cause armature core to rub pole shoes. This will decrease starter efficiency and damage the armature core.
FEELER Fig. 5—Adjusting Starter Drive Pinion Clearance
MyMopar.com
