Anchor
Check with a megger or with a lamp powered by a voltage of 220 V that the armature winding is not shorted to «mass». Voltage through the lamp is supplied to the collector plates and to the armature core. The burning of the lamp indicates the closure of the collector plates with «weight». When checking, the megger must show a resistance of at least 10 kOhm. Anchor having a short circuit with «weight», replace.
Using a special device, check the absence of short circuits between the sections of the armature winding and the collector plates, as well as the absence of breaks in the place where the leads of the winding sections are soldered to the collector plates.
Inspect the working surface of the collector. If it is dirty or burnt, clean it with a fine-grained sandpaper.
Check core runout against shaft trunnions. If it is more than 0.08 mm - replace the anchor.
Check the condition of the surfaces of the splines and trunnions of the armature shaft. They should not have scuffs, nicks and wear. If there are yellow marks on the surface of the shaft from the gear bush, remove them with fine-grained sandpaper, as they can cause the gear to seize on the shaft.
Drive unit
The starter drive must move freely, without noticeable jamming, on the armature shaft. The gear must rotate relative to the armature shaft in the direction of rotation of the armature under the action of a torque of not more than 0.27 Nm (2.8 kgf cm). The gear should not turn in the opposite direction. If there are nicks on the engagement part of the gear teeth, then under-grind them with a fine-grained emery wheel of small diameter.
If drive parts are damaged or severely worn, replace the drive with a new one.
Stator
Check with a megger or with a lamp powered by 220 V that the stator winding is not shorted to «mass». The voltage through the lamp is supplied to the common terminal of the winding and to the starter housing. If the lamp is on or the megger shows a resistance of less than 10 kOhm, and also if the windings show signs of overheating (insulation blackening), replace the case with windings.
Lids
Check the covers for cracks. If there are, replace the caps with new ones. Check the condition of the cover bushings. If worn, replace cap assemblies or bushings only. New bushings after pressing, expand to 12.015+0,03 mm.
Check the reliability of the fastening of the brush holders on the cover from the side of the collector. Brush holders of positive brushes must not have a short circuit with «weight». The brushes must move freely in the grooves of the brush holders. Replace brushes worn in height up to 12 mm with new ones, after rubbing them against the collector.
Check the force of the springs on the brushes with a dynamometer, which for new brushes should be 9.8±0.98 N (1±0.1 kgf) and, if necessary, replace the springs with new ones.
Traction relay
Check the ease of movement of the relay armature. Check with an ohmmeter whether the contact bolts of the relay are closed by the contact plate. If the contact bolts do not close, then disassemble the relay and clean the contact bolts and the plate with fine-grained sandpaper or a flat velvet file. In case of significant damage to the contact bolts at the point of contact with the contact plate, the bolts can be turned by 180°.