BMW 3 series E30

Since 1983-1994 of release

Repair and car operation

8.2.9. "Automatic machine"

THE GENERAL DATA

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

P – a parking (a lay brake);

R – a backspacing (backing);

N – a neutral;

D – advance.

So, get the engine, put the lever in position D – and have gone... Until will arrive into 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 "automatic machine" cannot "guess" that will come to 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 "automatic machine" will switch transfer only while you will press "gas" and will begin overtaking. Therefore on all "automatic machines" 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 example BMW 750.

P – R – N – it is already clear. The following position – D. In the given position of the lever-selector the onboard computer, receiving a signal from the gauge of position of a pedal of giving of fuel and from the gauge of speed of the car, switches transfers – from the first (lowest) to the fourth (accelerating). Braking by the engine at "gas" dump do not occur. But what to do, if it is necessary, for example, on 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 about 15–20 km/h, and having included 1, will move to a full stop. It is recommended on 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 positions: S – a sports mode, E – economic, M – manual. In a manual mode lever-selector position corresponds to the included transfer. Thus, you have an opportunity to operate transmission as semi-automatic. It is convenient at movement on slippery road, sand, on a dirt, i.e. There, where sharp changes of force on a wheel are inadmissible.

The sports mode differs from the economic only that gear changes occur at the 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 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-switching-off of an overdrive (JEEP Grand Cherokee, LINCOLN Mark VIII, etc.). In this case for deenergizing of the fourth transfer it is necessary to include the button in position "O.D.off".

It is necessary to pay attention that on many American cars FORD (Taurus, Escort, Town Car) the lever-selector has positions O.D., 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:

 – Oil level check only at the working engine;
 – On probeе 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 (). On probeе necessarily there is an inscription specifying a way of check. So, on JEEP Grand Cherokee oil level 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 Dextron III. It can be mixed with oils of the previous marks (Dextron II, IID and IIE). It has stabler вязность and more powerful additives improving work of a box. In transmissions of manufacture CHRYSLER oil MOPAR ATF Plus with which with success it is possible to replace on Dextron III is used. For transmissions of manufacture of firm ZF also use oil of type Dextron, however on cars BMW 540 and 740 synthetic oil ESSO ATF LT 71141 is used only. 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 bathed in it literally.

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

And the last: at occurrence of noise, vibration, rigid pushes at a gear change, the tightened switchings etc. Immediately address in the specialised centres on repair of automatic transmissions, especially at presence in your car of elektronno-operated transmission. Timely diagnostics will prevent considerable expenses for repair.

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