Toyota Land Cruiser 100/Amazon, Lexus LX 470

since 1997 release

Repair and operation of the car

Automatic Transmission (AT)

General information

For a complete set of the models considered in the present manual one of two types of 4-staged automatic transmissions can be used (with the raising transfer): A343F and A440F, and since 2002 vyp. – 5-staged AT. All transmissions are equipped with the blocked rotation converter (hydrotransformer). The converter provides direct coupling between the engine and driving wheels of the car.

In view of complexity of a design of AT, absence on free sale of replaceable internal components, and also need of use of the special equipment, authors of the present manual do not recommend to owners of cars to carry out capital repairs of transmission by own forces. In the present Chapter only procedures of diagnostics of the general refusals of AT, its routine maintenance, the main adjustments, removals and installations are considered.

Sometimes, in case of serious breakage, it is more reasonable and simpler to replace transmission, than to spend time and funds for restoration of the failed assembly. Regardless of the chosen way of introduction of the refused AT to action, independent performance of its removal and installation will help to cut down substantially expenses (before make sure that transmission really needs recovery repair).

Principle of functioning

Assembly of typical AT

Automatic transmission consists of the hydrotransformer with the blocking coupling, the raising planetary row, a transmission, a transfer case and a control system which part are hydraulic and electronic speak rapidly (address to an illustration above).

Planetary assembly of transfers consists of two planetary rows. A planetary row with frictional elements of management (the blocking coupling and a brake) is a part of a transfer case. Work of all transmission the electronic control unit operates. Switching of the high-speed modes is made by means of the car installed in salon selector growling. The selector by means of a cable is connected to valvate assembly, and with its help it is possible to set the range of the used transfers. Besides the selector in salon for a task of the special modes of functioning of transmission some switches are provided.

For prevention of breakages of AT at the wrong choice of high-speed range, for example, movement from "D" the clamp is provided in "R" on the lever of the selector, – "dangerous" switchings can be carried out only at the pressed clamp button. The lever of the selector can be installed in one of six fixed provisions: "Р", "R", "D", "N", "2" and "L", purpose of each of which is considered below.

Situation "P"

Gets out at a car parking. In this situation, in transmission all elements of management are switched off, and its output shaft is blocked, – the movement of the car is impossible. It is necessary to transfer the selector to situation "P" only after a full stop of the vehicle.

Situation "R"

Backing. It is possible to transfer the selector to a R position only after a full stop of the vehicle.

Situation "N"

Neutral situation. In a box all elements of management that provides lack of rigid kinematic communication between her leader and conducted by shaft are switched off. The mechanism of blocking of an output shaft thus is switched off, i.e. the car can freely move. It is not recommended to switch transmission in the situation "N" at the movement by a setup.

Situation "D"

Main mode of the movement. Provides automatic switching with the first on the fourth transfer. It is recommended at the movement in normal conditions.

Situation "2"

The movement only on the first and second transfers is authorized. It is recommended to use, for example, at the movement on twisting mountain roads. Switching on the third and fourth transfers is forbidden. On this range the braking mode is effectively used by the engine.

Situation "L"

The movement only on the first transfer is authorized. This range allows to realize as much as possible the braking mode the engine. It is recommended at the movement on abrupt descents, rises and off road terrain.

OD mode

Permission to use of the fourth, raising, transfers is carried out by means of the special OD button. If the button is in the drowned state and the lever is installed in the situation "D", switching on the raising transfer is authorized. Otherwise inclusion of the fourth (raising) transfer is forbidden. The condition of a control system in this case is determined by the control lamp "O/D OFF". In case of permission of the raising transfer the indicator does not burn, at a ban, burns. The mode is used at the movement with a constant speed on direct sites of the highway. It is necessary to avoid use of the O/D mode in city conditions, especially in a winter season when braking by the engine gains the vital value. It is also not necessary to include the mode of the raising transfer at a full load of the car.

Special programs

On cars with AT two control modes are put by gear shifting: "economic" (NORMAL) and "sports" (POWER). The choice is carried out by means of the special switch which is built in in the central console of the car.

Economy mode (NORMAL)

In this mode the minimum consumption of fuel takes place. Gear shiftings happen in the middle of the corresponding ranges of the engine, nature of the movement of the car quiet, smooth.

Sports mode (POWER)

At inclusion of this mode on the panel of prior the control lamp of "ECT POWER" lights up. In this mode there is the maximum selection of engine capacity, switching of a box is made in the upper bound of the corresponding ranges of turns of the engine. Acceleration performance of the car substantially increases, fuel consumption, respectively, increases.

Planetary transmission

Three planetary rows, three blocking couplings, four brakes and three couplings of a free wheeling are a part of a planetary transmission.

Power from the engine via the hydrotransformer is transferred to an entrance shaft of a planetary transmission.

Gear shifting is carried out by inclusion of a certain combination of brakes and couplings of a free wheeling therefore the frequency of rotation of an output shaft changes.

The transfer case contains one more planetary row, two blocking couplings and one brake.

Device of hydraulic part of a control system

Transmission

The hydraulic part of a control system consists of the oil pump, valvate assembly, electromagnetic valves, couplings and brakes, and also the channels connecting among themselves the listed elements. Pressure of working liquid created by the pump is used for management of frictional elements of transmission, feed of the hydrotransformer and greasing. In valvate assembly three electromagnetic valves of switching are installed. With their help the electronic block exercises control of gear shifting and blocking of the hydrotransformer.

Transfer case

Are a part of hydraulic part of a control system of a transfer case: a valvate box, the electromagnetic valve No. 4, a brake (B4), two blocking couplings (SZ, S4), and also the channels connecting among themselves the listed elements (address to an accompanying illustration). Purpose of a box – management of a planetary row which can be carried out or manually, or automatically electronic block.

Assembly of a transfer case is given on an illustration below.

Assembly of a transfer case

Electric part of a control system

The electric part operates gear shifting in a transmission and a transfer case, and also the blocking coupling of the hydrotransformer. It consists of three parts: the sensors of speed of the movement of the car (VSS), the sensor of provision of a butterfly valve (TPS) and other information sensors tracing parameters of a condition of transmission and transferring data of ECM (the electronic control unit); ECM which on the basis of the analysis of the data arriving to it defines the switching moments in a transmission and a transfer case, and also operates the blocking coupling of the hydrotransformer; and the executive part consisting of four electromagnetic valves.