8.1. General information

On the cars considered in the present manual the automatic transmission (AT) of U140E (the front-wheel models delivered on the American market) or U140F (all-wheel drive models) is established. Below AT U140F is considered.

AT U140F design

C1 — the advance Coupling
C2 — the Coupling of direct transfer
C3 — the Coupling of the lowering transfer
B1 — the Brake of the 2nd transfer

B2 — the Brake of the 1st transfer and a backing
B3 — the Brake of the lowering transfer
F1 — the Unilateral coupling No. 1
F2 — the Unilateral coupling of the lowering transfer

The components involved in work of AT

At the time of start-off from the place of AT acts as ordinary coupling, and during the movement performs work on gear shifting.

The AT main hubs are: torque converter (hydrotransformer), planetary reducer and hydraulic or electronic control unit. Hydrodriving disk brakes and disk coupling are applied to transition to other transfer relation in a planetary reducer.

The torque converter on the functions corresponds to hydraulic coupling. Its task includes implementation of coupling at start-off from the place and gear shifting.

The control system of transmission is a component of a control system of the engine and on the basis of the analysis of the data arriving from various information sensors (not necessarily directly related to functioning actually of transmission), chooses optimum from the point of view of profitability, smoothness of switchings and so forth the mode of functioning of AT. At failure detection in memory of the control unit the corresponding code registers (see Specifications to the Head Sistemy of electric equipment of the engine).

Components of a control system of transmission

1 — the Sensor of speed of a secondary gear wheel
2 — Em the switching SLT valve
3 — Em the switching SL1 valve
4 — Em the switching DSL valve
5 — Em the switching SL2 valve
6 — the Sensor of entrance turns of the turbine
7 — ATF temperature Sensor

8 — D/V of the modes "P"/" N"
9 — Em the switching S4 valve
10 — To/L malfunctions (MIL)
11 — No. 3 DLC Socket
12 — D/V of stoplights
13 — the Main switch of the O/D mode
14 — the Switch of the modes
15 — ECM

The only procedure of service of AT which implementation has to be made on a regular basis is check of level of its working liquid (ATF) which order of performance is stated in the Head Nastroyki and routine maintenance of the car. Need for regular replacement of ATF is absent.

Near a radiator of the cooling system of the engine ATF cooler is established.

Operating modes of transmission are described in the Head Governing bodies and methods of operation.

Thanks to application of D/V of the P / N modes start of the engine can be carried out only when the lever of the AT selector is in situation "P" or "N" that allows to prevent the casual movement of the car in start attempt.

In the present chapter only the most general procedures of service of AT lying within qualification of the average amateur mechanic are considered.