Repairing Armature

If armature commutator is worn, dirty, out of round or has high mica insulation between segments, commutator can be turned down in a lathe. Mica should then be undercut 1/32 in. deep with an undercutting machine and slots cleaned out to remove dirt or copper dust. If undercutting machine is not available, undercutting can be accomplished satisfactorily using a hacksaw blade. (See Fig. 5E-6, page 5E-5 for recessing mica separators.) Commutator should then be sanded lightly with No. 00 sandpaper to remove any burrs left from undercutting procedure.

Armature test procedure is described in Section 5E, or see Delco-Remy service bulletin No. 1M-152.

Inspect bushings (Item 21, Fig. 5L-8 and 5L-9) in drive end and commutator end frames, and commutator end thrust washer (22). Replace any excessively worn parts. Inspect bearing (23) in 4-pole type and replace if worn to excessive looseness.

For additional service and testing procedures, see Delco-Remy service bulletin No. 1M-152.

1. Thi-u-bolt nuts and lockwashers

2. Starter motor

3. Transmission cover (1904-65 Servi-car) 3A. Transmission cover (1966 Servi-car)

Figure 5L-5. Removing Starter Motor - Servi-car

Figure 5L-8. Removing Starter Motor -Electra-Glide


Reassembly is essentially the reverse of the disassembly procedure. The frame and field assembly should be completed first and checked with test lamp to make sure no grounds or open circuits have been caused by disassembly. Note that pole shoes (11) are notched on one end to accomodate connections at field coils. It is important that notched ends be placed at the lead ends of the coils so the pole shoes can be tightened properly and not drag on the armature.

Reassemble remaining parts in reverse order of assembly. Note that end frames (3 and 4) are notched to fit field frame ends. Also note correct location of thru-bolt insulator sleeve (2) next to field coil connection. Reconnect cables to solenoid switch and battery.

prestolite starter motor service


Remove thru bolts (1) with washers and lockwashers (2). Remove commutator end cover (3) holding brush plate (4) in place if necessary.

NOTE: End cover is marked with a double line next to the motor terminal. Also brush holder has a positioning notch which registers on the motor terminal insulator. See Figure 5L-12. Parts must be located correctly when reassembled.

Armature (5) and drive end cover (6) with bearing (7) are removed as an assembly. Bearing (7) is a light press fit on armature shaft and is staked in end cover (6).

NOTE: To prevent brushes from escaping holders, insert a spool of slightly larger diameter than the commutator underneath brushes when brushes are half exposed as armature is withdrawn from frame. In this way armature can be reinstalled without removing brushes from holders.

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