E30 series BMW 3

since 1983-1994 of release

Repair and car operation

+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engine
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. Exhaust system
- 8. Transmissions
   + 8.1.2. Specifications
   - 8.2. Automatic transmission
      8.2.2. Specifications
      8.2.3. Diagnostics of automatic transmission
      8.2.4. Draft of the selector of transmission
      8.2.5. Kick-down-mode cable
      8.2.6. The blocking switch / switch of a signal of a backing
      8.2.7. Removal and transmission installation
      8.2.8. Epiploons of automatic transmission
      8.2.9. "Machine gun"
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Good advice


8.2.9. "Machine gun"


Everything that is required to you, is to study position of the lever selector of management by transmission and its main positions:

P–parking (parking brake);

R–reverse (backing);



So, get the engine, put the lever in situation D – and went... Until will arrive on a place and do not switch off the engine. The car in process of pressing a "gas" pedal itself will get under way, switch transfers, to be dispersed, stop.

Certainly, even cleverest "machine gun" cannot "guess" that will come to you mind in a second - two. It works as though with delay: on a mechanical box you already would switch transfer, having prepared, for example, for overtaking, and "machine gun" will switch transfer only while you will press "gas" and will begin overtaking. Therefore on all "machine guns" additional functions are entered: position of the lever selector and (if transmission has electronic control) the switch of programs.

Let's consider appointment and functions of these additional devices on BMW 750 example.

P–R–N–already clearly. The following position – D. In this position of the lever selector the board computer, receiving a signal from the sensor of provision of a pedal of supply of fuel and from the sensor of speed of the car, switches transfers – from the first (lowest) to the fourth (accelerating). Braking by the engine when dumping "gas" do not occur. But what to do, if it is necessary, for example, on the slippery road or on descent?

Actions simple – compulsorily include the transfers necessary to you corresponding to positions of the lever selector 3-2 – 1: having dumped "gas" and having switched the lever on 3, you will feel appreciable braking by the engine in a range from 100 (at higher speed it is not necessary to use) to 40 km/h. Further, having switched on 2, it is possible to be braked to 15–20 km/h, and having included 1, will move to a full stop. It is recommended on the good free road in advance to be trained and learn to brake the engine to feel efficiency of such actions as they considerably differ from "mechanics" habitual to us.

The switch of programs has three situation: S–a sports mode, E – economic, M – manual. In a manual mode position of the lever selector corresponds to the included transfer. Thus, you have an opportunity to operate transmission as semi-automatic. It is convenient at movement on the slippery road, sand, on dirt i.e. where sharp changes of force on a wheel are inadmissible.

The sports mode differs from the economic only that gear shiftings occur at big turns of the engine.

At cars of other firms the lever selector can be issued differently, but functions and ways the same managements. So, on modern American and Japanese cars after a neutral there is a mode D that means overdrive (O.D.) also corresponds to the fourth, an overdrive gear. Sometimes on the lever selector there are only positions forward (D, 2 and 1) and there is a button of inclusion shutdown of an overdrive (JEEP Grand Cherokee, LINCOLN Mark VIII, etc.). In this case for switching off of the fourth transfer it is necessary to turn on the button in the situation "O.D.off".

It is necessary to pay attention that on many American FORD cars (Taurus, Escort, Town Car) the lever selector has O.D positions., D and 1, i.e. it is impossible to include compulsorily the second transfer that limits possibility of braking to the engine and movements on liftings.

With automatic transmission it is necessary for owners of cars to observe some rules:

Check oil level in a box not less often than two times a month.

Thus it is necessary to remember that:

 – level of oil check only at the working engine;
 – on щупе usually there are labels both for cold oil, and for the hot. If in a label the temperature at which it is necessary to check oil level is not designated, do it only on a heated-up box – after 10–15 km of run;
 – oil level, as a rule, check on a parking (R). On щупе surely there is an inscription specifying a way of check. So, on JEEP Grand Cherokee level of oil check only on a neutral.

Make oil replacement in a box through 30 000 km of run.

Thus it is necessary to consider that universal oil for automatic transmissions – Dextron. Modern oil is designated by Dextron III. It can be mixed with oils of the previous brands (Dextron II, IID and IIE). It has stabler vyaznost and more powerful additives improving work of a box. In transmissions of production CHRYSLER MOPAR ATF Plus oil which with success it is possible to replace with Dextron III is used. For transmissions of production of ZF firm also use Dextron type oil, however on BMW 540 and 740 cars only synthetic ESSO ATF LT 71141 oil is used. It use in all transmissions of this firm having a green firm label. To mix oils if necessary it is possible, but it is undesirable.

Tow the car with an automatic box not further 30 km and with a speed no more than 50 km/h in case the engine is faulty or in a box there is no oil.

Remember that at emergency to tow the car on a long distance it is possible, but it is necessary to fill in in a transmission in addition 2–3 l of oil that all details literally bathed in it.

Avoid an engine overheat as it can lead to a sharp overheat of oil in a box and, as a result, to box failure.

And the last: at emergence of noise, vibration, rigid pushes at the gear shifting, the tightened switchings etc. immediately address in the specialized centers for repair of automatic transmissions, especially at existence in your car of electronic operated transmission. Timely diagnostics will prevent considerable costs of repair.

Do not try to eliminate independently malfunction – your curiosity, self-confidence and economy on "kulibiny" will manage very expensively.