1942 - 1947 Chevrolet Shop Manual



	12-22

	Place one test prod on the armature and the other on the commutator, Fig. 47. If the test lamp lights, the armature is grounded and should be replaced. If the test lamp does not light, the armature is OK. Armature Test for Short Circuit	Place one test prod lead to the cover and the other on the brush holder, Fig. 49. If the test lamp lights, brush holder is grounded and should be replaced. If the test lamp does not light, the brush holder is OK. Brushes Check the condition of the brushes and if they are pitted or worn, they should be replaced. Check the tension of the brush holder springs; they should have enough tension to hold the brushes snugly against the commutator. Brush Ground Leads Disconnect the brush ground leads from the end frame and clean all terminals and replace. Check the insulation of the brush to field coil leads. The insulation should not be broken. Drive Housing Bushing Check the condition of the drive housing bushing. The armature shaft should fit snugly in this bushing; if it is worn it should be replaced. REASSEMBLY OF STARTING MOTOR Thread the shift lever through the slot in the drive housing, while at the same time engaging the bosses on the inner end of the lever in the sheave grooves on the drive mechanism, then slide the lever and the drive into the housing together, assemble the pivot bolt through the shift lever to the housing. Assemble commutator end washer and commutator end frame assembly to the armature. Assemble the armature and commutator end frame assembly to the starting motor housing. Thread the armature shaft through the drive mechanism, making sure to install the thrust washer between the drive and the drive housing bushing. Install the through bolts and tighten them securely. Assemble the field coil to brush lead machine screws. Oil commutator end frame bushing. Connect the starting motor to a battery and operate for running test. Assemble commutator cover band and install the starting switch insulators in the switch and assemble the switch to the motor. Replace starting motor on car making sure all connections are clean and tight. THE STARTING SWITCH The starting switch is designed to carry the heavy current required by the starting motor without loss and without heating.

	Fig. 48-Armature Test for Short Place the armature on the growler, and with a saw blade over the armature core, rotate the armature and test, Fig. 48. If the saw blade does not vibrate, the armature is OK. If the saw blade vibrates the armature is short-circuited and should be replaced. Commutator Inspect the commutator for roughness. If it is rough, turn down on a lathe until it is thoroughly cleaned up, then sand off the commutator with 00 sand paper. Insulated Brush Holder Test for Ground

	*Fig. 49-Insulated Brush Holder Test for Ground*