Repair and diagnostics of Bosch starters for VW, Audi, Skoda

• Valeo 438226;
• Cargo 113841;
• Krauf STB1323;
• Borg&beck BST2226;
• Magneti Marelli 063521230140.

Their price is usually slightly lower than the original, but all the spare parts we will talk about are interchangeable.

Design of the starter Bosch 02M911023P

It is worth noting the first and main difference between the original Bosch starter and previous models of the 2000s. The modernized starter is unsupported. That is, earlier the starter housing was attached to the gearbox crankcase, and its shaft was supported by a brass sleeve in the gearbox crankcase.

This led to the fact that the bushing wore out and the shaft got backlash. In some places, the starter gear could not engage with the engine flywheel. Thus, the starter could rotate idle without moving the engine flywheel. In the unit Bosch 02M911023P and its analogues this error was corrected, the starter became unsupported.

Its basic parameters:

• voltage 12 В;
• power 1.7 кВт;
• number of teeth on the gear — 9 or 10;
• number of mounting holes — 2;
• direction of rotation – counterclockwise (CCW).

In general, the VAG starter has a classic design—it is a 4-pole DC motor, which is powered exclusively by a battery. Like most reduction starters, the Bosch 02M911023P starter consists of:

• housing with stator winding;
• rotor shaft anchor with rotor winding and radial commutator;
• solenoid, which closes the contacts and supplies power to the electric motor itself, and also shifts the overrunning clutch (bendix) to transmit torque to the flywheel;
• gear units;
• roller clutch;
• brushes that are located on the back of the housing and feed the radial commutator and start the electric motor.

In general, the design of the Bosch 02M911023P starter is simple, which allows you to make any repairs with your own hands.

Main faults of the starter VAG 02M911023P, symptoms

Depending on the symptoms of the malfunction, the following Bosch starter parts can be considered as potentially vulnerable:

1. Brush pack. If you hear distinct clicks when starting the engine, the problem may be either in the brush gear or in the solenoid. Worn or destroyed brushes do not supply power to the radial commutator, so the starter does not start. Alternatively, the starter may not develop the required speed, this is also a symptom of worn brushes.
   
   
2. Roller clutch. When you try to start the engine, the starter motor rotates, but the flywheel and crankshaft remain in place. You will also hear a characteristic creaking, clicking, crunching sound.
   
   
3. Rotor winding, the armature. The most unpleasant situation is when all the listed symptoms relate to the armature. Only in a few cases repair is possible, and in other situations the rotor will have to be replaced.
   
   
4. Solenoid. When you turn the key in the ignition nothing happens, you can not hear the solenoids click, the starter does not rotate. Silence.
   
   

Repair, solutions to the problem with the Bosch starter

The easiest option is to replace a worn-out spare part with an original or analogue. But it is also the most expensive. Only complex repair of the starter by the hands of some service center will be more expensive. Moreover, it is much more expensive. However, there are some spare parts that usually cannot be restored. Here are some examples:

• original Bosch roller clutch, catalog number 1006209793;
• roller clutch ZEN ZN1619;
• solenoid, 2339305337 BOSCH;
• solenoid 235535RMFD CARGO;
• редуктор CARGO, 235025;
• starter brushes, ІКА, 0 1088 1;
• brush gear — CARGO 232700;
• needle bearing 8.4096.0 IKA.