To complete the work you will need:
- three- or two-jaw puller;
- homemade mandrel from a cup puller kit.
Disassembly
1. Remove the generator from the car (see above, "Generator - removal and installation").
2. Remove the voltage regulator (see "Voltage Regulator - Replacement").
3. Using a screwdriver, remove the ends of the stator winding leads from the spring-loaded contacts of the rectifier unit.
Note: You can check the condition of the rectifier unit and stator windings without disassembling the generator further. It is enough to carefully bend the winding leads to the sides. The verification procedure is the same as shown below.
4. Using an 8 mm open-end wrench, unscrew the three bolts securing the rectifier unit (remembering how the insulating and thrust washers are installed).
5. Using a 12 mm wrench, unscrew the contact bolt nut.
6. Remove the rectifier block.
7. Using a marker, mark the relative positions of the front and rear covers of the generator (to simplify assembly).
8. Using an 8 mm socket wrench, unscrew the four bolts holding the front and rear covers of the generator.
9. Using a slotted screwdriver, carefully move the generator covers apart.
10. Remove the back cover and take out the contact bolt from it (with an insulating washer put on it) and a plastic bearing sleeve.
Recommendation. To determine the technical condition of the rear bearing, rock it from side to side and vigorously rotate its outer ring. The bearing should not have significant play, the ring should rotate freely without jamming or extraneous noise. The faulty bearing must be replaced.
11. Using a marker, mark the relative positions of the stator and the rear cover.
12. Using a screwdriver, remove the stator from the rear cover of the generator.
13. To determine the technical condition of the front bearing, hold the pulley with your hand, rotate and rock the front cover from side to side.
Recommendation. If the bearing is seized, has significant play, or makes a lot of noise when the cover is rotated vigorously, it must be replaced.
Tip: The manufacturer does not recommend replacing the front rotor bearing, as the bearing is crimped into the front cover of the generator. But, given that the cost of a bearing is significantly lower than the cost of a new front cover and, especially, the generator assembly, it makes sense to press out and replace the faulty bearing.
14. If it is necessary to replace the front generator bearing, use a 24 mm socket wrench to loosen the pulley mounting nut while holding the pulley with sliding pliers.
15. Remove pulley 3 with spring and flat washers 2, and spacer sleeve 1 from the rotor shaft.
16. Using a hammer with a rubber striker, press the rotor out of the front bearing (to do this, we screw the pulley fasteners onto the rotor shaft thread flush with the end).
17. If it is necessary to replace the front generator bearing, install the front cover in a vice.
18. Having selected suitable mandrels from the cup puller kit, we press out the bearing from the mounting hole of the front cover.
19. Having secured the rotor in a vice with soft pads on the jaws, using a universal puller of the appropriate size, press the rear bearing off the rotor shaft.
Examination
1. By applying the ohmmeter probes to the rotor contact rings, we check the excitation winding for breakage. The resistance of a serviceable excitation winding should be 5-10 Ohms.
2. By connecting the ohmmeter probes to any contact ring and to the rotor, we check the excitation winding for short circuit to ground. If the rotor winding is in good condition, the ohmmeter should show infinite resistance.
3. By alternately connecting the ohmmeter probes to the stator winding terminals, we check the stator windings for breaks. If there is no break, the ohmmeter will show a small electrical resistance.
4. Having connected the ohmmeter probes to any terminal of the winding and to the stator, we check the stator winding for the absence of a short circuit to "ground". If there is no short circuit, the ohmmeter should show infinitely high resistance.
We replace the faulty rotor and stator.
Note: A healthy semiconductor diode conducts electric current in only one direction. If the diode does not conduct current or conducts current in both directions, then it is faulty.
5. Connect the negative lead of the ohmmeter to the diode lead, and the positive lead to the body of the diode being tested (or to the plate into which it is pressed). A good diode should not conduct current (resistance tends to infinity).
6. Change the tester probes. If the diode is good, the ohmmeter should show electrical resistance.
7. We check other diodes of the rectifier block in the same way.
Assembly
Warning. Before pressing the bearing into the front cover of the generator, it is necessary to check the bearing seat and, if necessary, use a knife or scraper to restore the chamfer where the edges of the hole remain dented. When pressing the front bearing into the cover, force must be applied only to the outer ring of the bearing.
1. Having selected suitable mandrels from the cup puller kit, press the new bearing into the front cover of the generator until it stops.
2. Using light hammer blows through a punch, restore the bearing crimp in the cover.
3. Using a tube of suitable diameter (you can use a 19mm deep socket) we press the rear bearing onto the rotor shaft until it stops.
Warning: Before installing the alternator rear bearing, make sure the shaft is securely clamped in a vice. Place a wooden block of suitable size under the rotor shaft to avoid damaging the front impeller of the rotor during pressing. To avoid damage to the bearing, impacts should only be applied to the inner ring of the bearing.
Further assembly of the generator is carried out in the reverse order of disassembly. In this case, we align the marks applied to the covers and the generator stator. Finally, tighten the tie bolts evenly, crosswise, in several steps of half a turn. Having tightened the bolts, make sure that the rotor rotates easily (rotor jamming may be caused by skewing of the covers). Before installing the plastic casing, make sure that the stator winding terminals are securely fastened.