ROD AS 4T7011 - Caterpillar

Table 1
Tools Needed    
6v-7070 Digital Multimeter
or Equivalent    
Growler Tester    A visual check of the field windings should be done first. Check for wear and damage. Check all of the connections for imperfections in the solder joints. Field Winding Ground - Test
Illustration 1 g00584871
Field Winding Ground Test (1) Field winding leads. (2) Motor (Mtr) terminal lead.
Place the multimeter in the "20M" position. Touch the multimeter leads between each field winding lead (1) and the case of the starting motor.
Touch the multimeter leads between the motor terminal lead (2) and the case of the starting motor.
Each reading should be greater than 100,000 ohms. The multimeter should read "0.10" or a value that is greater.
If the meter reading is less than 100,000 ohms, the field winding is grounded. The case of the starting motor and field windings must be replaced. Field Winding Continuity - Test
Illustration 2 g00584873
Field Winding Continuity Test (1) Field winding leads. (2) Terminal lead.
Place the multimeter on the "200 ohm" scale. Touch the meter leads between field winding leads (1).
Touch the meter leads between each field winding lead (1) and motor terminal lead (2).
Each reading should be 00.0 to 00.1 ohms.
If the meter reading is higher than the meter reading in 3, there is an open in the field winding. The case of the starting motor and the field windings must be replaced. Armature Short Circuit - Test
Illustration 3 g00584876
Armature Short Circuit Check (3) Armature. (4) Growler tester.
Place armature (3) on growler tester (4). The tester needs to be turned to the ON position.
Hold a hacksaw blade against the armature core. Slowly rotate the armature while the blade is against the core.
The blade should not vibrate or the blade should not be attracted to the armature core.
If the blade vibrates or the blade is attracted to the core, the armature has a short. The armature must be rebuilt or replaced. Armature Ground - Test
Illustration 4 g00584879
Armature Winding Ground Test (3) Armature.
Place the multimeter in the "20M" position. Touch one meter lead on each commutator bar and the other lead on the armature core.
Each multimeter reading should be greater than 100,000 ohms. A meter reading of "0.10" or a value that is greater is acceptable.
If the meter reading is lower than 100,000 ohms, the armature is grounded. The armature must be rebuilt or replaced. Armature Continuity - TestSpecial equipment is needed to test the armature for an open. If the commutator is pitted or the bars are burned, the armature has an open. The armature must be replaced.Armature Runout - Check
Illustration 5 g00584880
Armature Runout Check (5) Commutator.
Check the runout of the armature (TIR) of the commutator (5). The maximum TIR that is allowed is 0.05 mm (0.0020 inch).
If the TIR is too great, the armature must be replaced. Commutator Outside Diameter - Check
Illustration 6 g00584882
Commutator Outside Diameter Check (5) Commutator.
Check the outside diameter of commutator (5). The new diameters of the commutator and the minimum diameters of the commutator are provided in the Specifications section.
If the armature is