DIY MTZ starter repair

In detail: do-it-yourself MTZ starter repair from a real master for the site my.housecope.com.

In this article, we will tell you how to repair a starter with your own hands, using the example of repairing a starter BATE 426.3708

You will need:
socket head "13", knob, screwdriver, keys "10", "8".

The stop ring is secured with a retaining ring installed underneath.

Insulated brushes A are soldered to the terminals of the stator windings, and non-insulated brushes B are soldered to the brush holder. When removing the brush holder, insulated brushes remain on the terminals of the stator winding.

Four field windings are fixed in the starter housing.

This is how the details of the starter drive look like: 1– gear; 2 – drive lever; 3 – overrunning clutch; 4-Belleville washer.

Disassemble the traction relay only when it needs to be repaired.

The traction relay coils are installed in a non-separable case, therefore, if they are damaged, replace the traction relay assembly.

41. Check the condition of the stator winding. To do this, turn on the test lamp in the 220 V AC circuit and connect the wire to one of the terminals of the stator winding, close the other end of the circuit to the case. If the lamp is on, it means that the insulation of the winding is damaged. Replace winding or stator. Check the second winding in the same way.

When testing with 220 V, be careful not to touch live parts of the starter with your hands.

The stator windings can be checked with a megohmmeter. Connect one contact to the terminal, the other to the stator housing. The resistance of the windings must be at least 10 kOhm. If it is less, replace the stator.

42. Examine the anchor. If the collector is dirty or there are risks, scratches on it, sand it with fine glass cloth. If the collector is very rough or if mica is protruding between the plates, grind the collector on a lathe and then grind with fine glass cloth. The runout of the core relative to the shaft journals should not exceed 0.08 mm. If the runout is greater, replace the armature.

Video (click to play).

43. If there is yellow plaque from the bearing on the armature shaft, remove it with a fine sandpaper, otherwise it will cause the pinion to jam on the shaft. If there are scuffs and nicks on the surfaces of the journals and shaft splines, replace the armature.

44. Check the reliability of soldering the leads of the armature winding to the collector plates. Inspect the winding at the ends of the armature: the diameter of the winding should be less than the iron package of the armature. If the diameter is larger, replace the anchor

45. Check the condition of the armature winding using a test lamp in the AC 220V circuit. Connect the wires to the collector plate and the armature core. If the lamp lights up, then there is a short circuit of the armature winding or collector plate to ground. In this case, the anchor must be replaced.

The armature windings can be checked with a megger. Connect one of its contacts to the collector, the other to the armature core. The resistance of the windings must be at least 10 kOhm. Replace the armature with less resistance.

46. ​​While holding the overrunning clutch, try to turn the starter gear in both directions: it should rotate freely only clockwise. If the gear turns in both directions, replace the drive.

47. Slide the starter drive onto the armature shaft. It should move freely, without jamming along the splines of the shaft.

48. If the drive parts are badly worn or damaged, replace the drive. If nicks are found on the lead-in part of the gear teeth, grind them with a fine-grained small-diameter emery wheel.

49. Inspect the manifold side starter cover and intermediate support. If cracks appear on these parts, replace them. Also inspect the bushings in the cover and support, in which the armature shaft rotates.If severe wear or mechanical damage is found, replace the cover or support with defective bushings.

50. Inspect the bushing pressed into the clutch housing. If the bushing is worn out or there are scuffs or pits on it, replace the bushing.

The bushing is located in a blind hole in the clutch housing and is therefore difficult to access. To remove the bushing, screw a suitable size tap into the bushing until it stops at the bottom of the hole, as if cutting a thread in the bushing. With further rotation of the tap, the sleeve will be pressed out of the hole.

52. Check the movement of the brushes in the holders. The brushes should move easily without jamming. Check that the brush holders are securely fastened: they must be firmly attached.

53. Holders of insulated brushes must not be connected to ground. Check this with a test lamp.

54. Check the force of the springs pressing the brushes using a dynamometer. To do this, insert the armature into the cover from the drive side, install the housing and the brush holder

55. Insert the brushes into the brush holders. At the moment of separation of the spring from the brush, the force should be in the range of 9.0-11.0 N (0.9-1.1 kgf).

56. Check the resistance of the traction relay windings with an ohmmeter. The resistance of the retraction winding should be within 0.52–0.59 Ohm (dashed red lines), and the holding one - 0.725–0.795 Ohm (solid yellow lines) at an ambient temperature of +15 to +25 ° С. The traction relay armature must move freely in the housing, without jamming.

Simultaneously with checking the resistance of the winding, check if the contact plate closes the contact bolts of the traction relay. If the ohmmeter shows infinity, then either there is an open circuit in the winding, or the plate does not close the contact bolts. In the first case, the traction relay must be replaced.

Starter repair is a troublesome business, but by doing it yourself, you can save your family budget. During operation, the starter is constantly under heavy loads, and is exposed to dust, moisture, dirt and oil, which contributes to the rapid destruction of the insulation of the electric motor and breakdowns of the drive mechanism.

We have already written about some of the signs of a starter malfunction and about checking and repairing the retractor relay. Another malfunction that leads to the repair of the starter is the slip of the overrunning freewheel clutch - bendix, resulting from contamination of the grooves and rollers. In this case, when the starter is turned on, the noise of a rotating armature is heard, and the crankshaft is in place (this is good shown in instruction video for starter repair at the bottom of the page). Repair is indispensable here.

You can check the bendix directly on the car without removing the entire unit. For this you need:

  1. Include transmission;
  2. Depress the brake pedal;
  3. Start starter.

If at the same time you hear the sound of the armature rotation, then the bendix is ​​slipping and needs to be repaired or replaced with a new one.

To begin with, you can try to carry out a small repair and remove the contamination of the bendix without disassembling the starter. For this:

  • remove the starter from the car (Video instruction at the end of the article);
  • immerse it whole in a container of gasoline and leave it there for several hours;
  • without removing the starter from the container, turn the clutch gear several times for better flushing of the grooves;
  • take out and dry the starter.

If, as a result of such a "not tricky" repair, the malfunction is not eliminated, you will have to remove and disassemble the overrunning clutch.

Starter repair with disassembly of the bendix is ​​performed in the following order:

  1. Before disassembling the bendix, first of all, it must be removed from the anchor (look at the video below).
  2. Then very carefully flare the folded edge of the casing and remove it from the outer race.
  3. Then remove the springs and stretch them so that when they are free, they increase by about 10 mm.
  4. Next, it is necessary to wash all the parts of the bendix, the grooves of the outer cage in gasoline, and clean out the nicks and burrs on the working surfaces.
  5. Do not forget to lubricate all structural elements with engine oil before assembly.

If you properly roll up the edges of the casing, then such a repair of the starter will extend the life of the bendix for several more years.

A car starter is a sophisticated electrical device that can be used to start the engine by simply turning the ignition key. Any of them is designed for hundreds of thousands of successful launches, and with proper care, it can last a long time, starting a car engine without problems in any conditions. The lack of timely diagnostics and replacement of worn parts can lead to such a situation that far from home or a car service, it will simply fail, delivering a huge number of problems to the car owner.

It is worth noting that although an independent starter repair is possible, its implementation requires experience and a set of elementary tools, which are simply not at hand in a long trip. Accordingly, repairing the starter motor may not be possible, which is almost guaranteed to immobilize the vehicle. But it is far from always impossible to start the engine due to a malfunction of the starter, and before undertaking its "repair", you should pay attention to other components - for example, a flywheel or a storage battery. In addition, it is impossible to repair a starter with your own hands if you do not know how it works.

At the heart of any starter is a powerful short-lived electric motor.

Starter operation when trying to start the car is as follows:

  • after turning the ignition key, voltage begins to flow to the windings of the electric motor;
  • the bendix pushes out the gear, which is connected to the flywheel;
  • after a successful crankshaft spin, the bendix gear is thrown back to its original position, at the same time the electric circuit is opened and the starter stops working.

Despite the fact that there are several types of starters, their electrical part is the same, and the only differences are in the mechanisms for automatic decoupling from the flywheel. The friction damper may also differ. In addition to the classic design, the most widespread is a starter with a planetary gearbox - it is installed on diesel and powerful gasoline engines. Such designs have some advantages over classic options:

  • more compact dimensions;
  • increased efficiency;
  • easier start of the motor with a weak battery charge;
  • this starter requires less starting current, which increases the reliability of starting in cold weather.

Of course, a more complex design makes it much more difficult to repair the device yourself.

A qualitative check of this unit is impossible without dismantling it. It is best to carry out work in a pit, which will provide the ability to move freely under the car. A standard set of wrenches will be required from the tools, and the presence of socket wrenches with a flexible extension will greatly simplify the task. Dismantling is carried out in several stages.

  1. The terminals are removed from the storage battery.
  2. Electrical cables are removed from the pins of the solenoid relay and terminals.
  3. The motor protection is dismantled.
  4. After unscrewing the nuts that secure the starter to the engine block, it can be removed.

Carrying out periodic control of the brushes, you can timely notice a critical decrease in their height, which should not be less than 12 mm. To get to the brushes, unscrew the screw securing the contact wires and squeeze the spring - after that they can be freely removed. After measuring the length, a decision is made to install new ones or return the old ones to their place. As practice shows, if the starter is already dismantled, and new brushes are in stock, it is better to replace them. It should be understood that replacing the starter brushes is an operation that must be performed regularly, especially with frequent engine starts.

This is a more laborious process than removing the brushes.Initially, it is required to remove the washer from the axle and unscrew a pair of tie bolts. After disconnecting the casing of the device, you will have to remove the tubes of insulation of the screed bolts from it. Now you should evaluate the external condition of the collector and the windings. There should be no obvious black marks on them, as well as on the collector itself. If they are still there, then it is advisable to replace the collector, although it can be cleaned with fine-grained emery paper as a temporary measure.

To do this, you will have to get the anchor out of the case. To get to it, you must remove the washer from the axis of the anchor itself, strip the axis of the lever and knock it out - after that it will be possible to remove the anchor along with its drive. The clutch drive lever is removed and the free rotation of the gear is checked by hand: it should be completely free in one direction, and completely blocked in the opposite direction. Chips, and even more so chips should not be detected. If free rotation is difficult or impossible, and there are traces of wear on the teeth, the coupling together with the gear are replaced with new ones - it is unacceptable to operate such a device.

In the process of gradual disassembly of the starter, using an ohmmeter, the windings of the starter itself and the armature are tested for the presence of traces of short circuits. Checking the starter armature is mandatory, since then disassembling it for the sake of this is quite problematic. Reassembling the assembly should be done carefully and slowly. Before that, all surfaces are thoroughly cleaned of dust and dirt, and plastic parts are necessarily lubricated with one of the special lubricants, for example, lithol. All metal parts, which are in excess in the starter, are treated with engine oil. How you can perform high-quality and self-diagnosis is shown in the video: