Starter Motor bench testing report

Part of  4841 electrical is starting systems. In which we disassembled a starter motor, did a number of tests, and then reassembled it.
The first test we did was a no load test on the starter motor using the bench tester. Voltage read 12.8 volts and current read 38.8A which is normal. After we disassembled the starter, we did a ground circuit test between each commutator segment and the armature shaft. We got readings of infinity which means it is an open circuit, which means it is not grounding to the shaft, which is a pass. Next was a continuity test between each commutator segment. We got readings of 0 ohms on the ohm meter which means there is a circuit, but no resistance, which is a pass. We then tested the commutator diameter and undercut, these were both passes. We then checked the commutator diameter for its circle shape using the dial test indicator, this was in good order.
We then did a test for internal short circuits in the armature using the growler. The hacksaw blade did not vibrate at all so this was a pass.
We then did a visual inspection of the field coil and pole shoes. There were no signs of overheating, burning, physical damage or poling that could cause the starter motor to malfunction, so this was a pass.
We then tested the field coils for continuity. We got a reading of .02 ohms, which means there is a circuit with minimal resistance, which is a pass. Next we tested the field coils for grounding. We got a reading of infinity, which means it is a open circuit and the field coils are not grounding to earth, which is a pass.
We then checked the length of the brushes. All four were 15 to 16mm long which means they all make suitable contact with the commutator, which is a pass. We then tested the solenoid. The first part was the pull in windings. By connecting the power supply to the S and M terminals, the physical action was to pull in the plunger. It did this and drew a current of 20A. We found this to be higher than spec, but after other groups getting the same result, we concluded this to be normal for that type of solenoid. We then tested the hold in windings test. By connecting the power supply to the S terminal and body of the solenoid, it should hold the plunger in. It did this and drew 8A of current, which is in spec, which is a pass. It takes 20A to pull the plunger in and only 8A to hold it in, because it is easier to hold it in that pull it in.
The pinion clutch and bushes were all in good order so these were also passes.
We then reassembled the starter motor, before perfoming another no load test. We found it used 13.2V and 37A which is a pass.