Infiniti QX4 service since 1996 of release
1. Introduction
2. Maintenance instruction
3. Routine maintenance
4. Engine
5. Cooling and heating systems
6. Power supply systems and managements
7. Start and charge systems
8. Transmission line
8.1. 4-step automatic transmission
8.1.1. General information
8.1.2. AT problem diagnostics - the general information
8.1.3. Electronic and hydraulic control system of 4-step AT
8.1.4. Removal and transmission installation
8.1.5. Replacement of an epiploon of lengthening of transmission
8.1.6. Removal and installation of a cooler of ATF
8.1.7. Removal and installation of klapanny assembly of a hydraulic contour of management of AT
8.1.8. Removal, check of a condition and installation of a driving cable of blocking of switchings
8.1.9. Adjustment of a drive of switching of AT
8.1.10. Adjustment of the sensor switch of provisions of AT / permission of start
8.1.11. Major maintenance of AT
8.2. Transfer case
8.3. Differentials, power shafts / semi-axis
8.4. Driveshafts
9. Brake system
10. Suspension bracket and steering
11. Body
12. Electric equipment



8.1.2. AT problem diagnostics - the general information

AT refusals occur on one of the following five reasons more often: decrease in efficiency of return of the engine, violation of adjustments, malfunctions of hydraulics, mechanical damages, or failures of the onboard processor / its alarm chain. Problem diagnostics always should begin with the simplest checks: estimate level and ATF condition (see. Head Routine maintenance), check adjustment of a cable of management by gear shifting and the sensor switch of provision of transmission. Further, carry out trial runs of the car for the purpose of determination of efficiency of the brought corrections. If to eliminate a problem it was not possible, it is necessary to drive away the car on car repair shop for more detailed diagnostics with use of the special equipment. The description of refusals of AT some of symptoms see. Diagnostics of malfunctions of knots and car systems.

Primary checks


  1. Warm up transmission to normal working temperature during a short trip.
  2. Check ATF level (see. Head Routine maintenance):
    • If liquid has not enough, make the corresponding adjustment, having added necessary quantity of fresh ATF. Be convinced of correctness of the carried-out adjustment according to indications measuring щупа, then check transmission on existence of signs of external leaks (see below);
    • If level is too high, merge surplus of ATF, then check it on existence of traces of presence of the cooling liquid, testifying violation of tightness of internal partitions of the radiator separating its heat exchanger from lateral tanks with ATF (see. Head of System of cooling and heating);
    • If ATF is made foam, empty transmission and fill it with fresh liquid — merged check on existence of traces of presence of cooling liquid.
  3. Check installation of turns of idling of the engine.

If the engine not as it should be, it is not necessary to start performance of primary checks of transmission until the corresponding corrections will be made.

  1. Check freedom of moving of a cable of a drive of a butterfly valve.
  2. Check draft of a cable of management of gear shifting (see. Adjustment of a drive of switching of AT), make sure of correctness of adjustment and freedom of its moving.

Diagnostics of leakages of ATF

General information

The majority of leaks easily come to light at visual check. Repair usually consists in replacement of the corresponding defective epiploon or laying. If to reveal a leak source during external survey it is not possible, act, as it is described below.

First of all it is necessary to exclude probability of a mistake in definition of the nature of leak. It is not necessary to confuse ATF to impellent oil or brake liquid (transmission liquid usually has dark red color).


  1. For identification of a source of leak make short (some kilometers) a trip, then park the car over the outspread blank sheet of a cardboard. Later few minutes the source of leak can be revealed in the wake of liquid dripping on a cardboard.
  2. Attentively examine a suspected site and a surface surrounding it, special attention giving to a joint of interfaced prokladochny surfaces. For the purpose of expansion of a corner of the review use a pocket pocket mirror.
  3. If to reveal a leak source still it is not possible, carefully wipe a surface of a suspected site the rags moistened with solvent, then dry it.
  4. Make one more short trip, this time often changing speed of movement, then again examine the cleaned suspected site.

After identification of a source of leak it is necessary to define and eliminate the reason of its development, and only then to pass to performance of necessary recovery operations. Replacement of the damaged laying will not lead to desirable result if to leave not eliminated the defect of the interfaced surface which has led to an exit of laying out of operation. So, the deformed flange it is necessary отрихтовать.

In below-mentioned subsections the most typical reasons of development of leakages of ATF and a condition which should be executed that there was no recurrence are listed.

Part from the listed requirements cannot be executed without use of the special equipment. In this case the car should be driven away on car repair shop.

Leaks through prokladochny surfaces

Periodically examine a cover on the right side of a transmission case. Check existence on the places and reliability of a tightening of fixing bolts, watch, that on a cover there were no traces of mechanical damages.

Excessively hard tightening of fixing bolts, damage of a sealing surface of a case of transmission, laying destruction, and also emergence of cracks belong to number of the possible reasons of development of leaks through a cover or a poroznost of walls of a case. If laying of a cover or a case of transmission is formed by a hermetic pillow, the probability of the wrong choice of type of the last is not excluded.

Leaks through epiploons and cuffs

Excessively high level of ATF, violation of passableness out of operation belong to number of the most typical reasons of an exit of epiploons of transmission ventilating сапуна, mechanical damage of walls of a landing nest, damage actually an epiploon, or the wrong installation of the last. The probability of damage of a pin of the shaft passed in an epiploon, or excessive люфт the last as a result of wear of bearings is not excluded also.

Check a condition and correctness of landing of a sealing cuff of a directing tube measuring щупа. Periodically examine on existence of signs of leaks a surface around an arrangement of a driving gear wheel of a speedometer or the sensor of speed (VSS). In case of need make replacement of a sealing ring.

Leaks through defects in walls of a case of transmission

Formation of cracks or time in a body of a case of transmission can be the reason of development of leakages of ATF. Consult with specialists of car-care center.

Check tightness of shtutserny knots of connection of hoses of a cooler of ATF.

Leaks through сапун and a jellied mouth

Leaks through сапун or a jellied mouth can occur owing to excessive filling of transmission, hit in ATF of cooling liquid, passableness violation сапуна or returnable openings.

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8.1.1. General information
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8.1.3. Electronic and hydraulic control system of 4-step AT