For repair, the starter is removed from the engine by unscrewing the bolts of the clamps
Disassembly of the starter should be done in the following order:
- - remove protective tape 1 (see Fig. 1);
- - unscrew the screws 26 fastening the brush cords and, lifting the brush springs 25, remove the brushes from the brush holders;
- - unpin the connection of the lever 12 with the rods 11 of the armature of the traction relay and remove the pin 35;
- - unscrew and remove two tie rods 33;
- - remove cover 14;
- - remove the housing together with the traction relay;
- - unscrew the four bolts securing the holder 22 of the intermediate bearing;
- - remove anchor 2 from cover 14 together with the drive;
- - remove two crackers installed in the slots under the thrust ring 17;
- - remove the drive assembly from the armature shaft.
Parts and assemblies of the starter must be carefully inspected for malfunctions and breakdowns.
The covers on the drive and manifold sides must not be cracked or damaged;
- - gear and electric brush teeth must not be chipped; the leading pin installed in the lever 12 must be securely fixed in the lever and not have a working out;
- - electric brush springs should not be broken. Worn and damaged parts must be replaced.
Electric brushes with a height of less than 14 mm must also be replaced (the height of the brushes is measured from the point where the spring touches to the ground working surface).
Contact bolts 5 and contact disk 6 of the traction relay must not have burn marks on the working surface.
In case of burning, the contacts are restored by the methods given in the description of the maintenance of the starter.
The traction relay is checked for the integrity of the retracting and holding windings and for coil short circuits.
The check is performed with Ts437, Ts20 ampervoltmeters or any others that allow you to measure resistance with an accuracy of 0.1 Ohm.
The resistance of the pull-in winding is measured. It should be 0.9 ± 0.2 ohms. The resistance of the holding winding should be 5 ± 0.8 ohms.
It should be remembered that the resistance values are indicated for cold (unheated) coils (ambient temperature 20 ± 5˚С).
If the resistance of the coils differs from the above values, then there are short circuits in the coils and the relay must be replaced.
At the starter armature, it is necessary to inspect the collector, check the winding for a turn short circuit and for the housing. Particular attention should be paid to the condition of the two oval holes located on the splines of the shaft.
The holes should not have rectangular ledges. Such development leads to jamming of the drive mechanism during start-up, and the armature must be replaced.
The surface of the anchor collector is wiped or cleaned as shown in the maintenance description.
If it is necessary to groove the collector, it is then polished with a fine sandpaper. The size of the collector after grinding must be at least 56.05 mm.
The armature is checked using PYA-5, PYA-533 devices, on the Emet-54, Electrotester or other stands that have a prism and a transformer device for checking anchors.
The starter stator, after wiping and cleaning from dust and accumulated dirt, is checked for a short circuit of the windings to the housing.
Two bolts inside the stator are preliminarily unscrewed, securing the tires to the housing.
Checking is carried out with a test lamp for 110 or 127 V, which is included in the set of devices or stands.
Faulty coils must be removed, the damaged area isolated and reinstalled in the housing.
After fixing the pole pieces with the coils, it is necessary to caulk the starter housing to prevent the screws securing the coils from self-unscrewing.
It is also necessary to check the starter armature shaft support bushings installed in covers 14 and 31 (see Fig. 1).
The bushing in the cover 14 on the drive side can be worn out to a size of no more than 19.615 mm. The size of the sleeve in the cover 31 on the collector side should not exceed 18.105 mm.
If the bushings are larger than specified, the bushings must be replaced. The inner diameter of the bushings after their pressing and boring should be:
- - in the cover on the drive side 19.5+0.045 mm;
- - in the cover on the collector side 18.0+0.035 mm.
After replacing parts and repairing, the starter is assembled in the reverse order of disassembly. In this case, the bolts 21 (see Fig. 1) for fastening the holder of the intermediate bearing 22 must be put on the BF-4 glue.
Pour 10 drops of turbine or engine oil into the lubrication holes located under the screw plugs 10, 16 and 27.
Yako shaft splines before assembly, they are lubricated with CILTIM-203 grease. In the assembled and lubricated starter, the anchor should turn easily by hand when force is applied to gear 15.
The assembled starter must be adjusted, for this the starter must be clamped in a vise or a device that ensures its immobility.
The circuit shown in fig. 2. A 24V pilot lamp is connected and a 16mm thick shim is placed between the gear and thrust ring.
Switch 3 turns on. After the starter traction relay is activated, the lamp should not light up.
When installing a gasket with a thickness of 11.7 mm, the lamp should light up when the relay is activated.
If these conditions are not met, the traction relay is adjusted: when the lamp lights up and the gasket is 16 mm, it is necessary to screw the screw into the armature 9 of the relay (see Fig. 1); non-lighting lamp when laying 11.7 mm requires unscrewing the screw from the armature.
The design of shims is shown in fig. 3.
Adjusted starter is tested for no-load current from 24 V batteries or from a DC source of the same voltage.
The operating current of the starter should not exceed 110 A. If the current is much higher, then the starter armature rotates tightly and finishing work is necessary.
A checked and adjusted starter can be installed on the engine. At the same time, it must be remembered that the fastening of the starter installed on the engine may loosen after several attempts to start.
Therefore, after installing the starter on the engine, it is recommended to make 3 - 5 test short starts and finally tighten the bolts of the starter fastening clamps. The tightening torque must be 3 kgcm.