Automatic transmission "Aisin": review, diagnosis and repair of typical faults

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:41

In Japan, a lot of cars are made with automatic transmission. This applies to almost all brands - Nissan, Honda, Lexus, Toyota, Mitsubishi. I must say that the Japanese have fairly reliable models of automatic transmissions. One of these is the Aisin automatic transmission. But she also gets into trouble. In our article, we will talk about the features of the Aisin automatic transmission 4-st and 6-st, as well as the reviews of car owners about this transmission.

Characteristic

So what is this transmission? This is a Japanese-made automatic transmission, which can be designed for a different number of steps. Initially, only four-speed boxes were produced. Now automatic transmission "Aisin" 6-speed has gained great popularity

This box is installed on most budget and middle class cars. As for the premium segment, it provides for an eight-speed gearbox of the brandAA80E. The Aisin automatic transmission device includes:

• Torque converter.
• Hydroblock.
• Planetary gear set.
• Differential (applies to front wheel drive cars).
• Cooling system.
• Pump.
• Control system.

The inside of the box is filled with special oil. This is ATP fluid. It not only lubricates friction parts, but also allows you to transfer torque, performing the function of a "wet" clutch.

Reviews

Motorists in the reviews of the Aisin automatic transmission note that it is quite reliable. Among the advantages of this box in the reviews, they note:

• Small yet efficient hydraulic unit. This contributes to a more compact size of the box (which is especially important for passenger cars) and provides effective lubrication of parts.
• Fully automated box control. This allows you to use less fuel.
• Smooth shifting.
• Good dynamic performance. If a conventional torque converter slows down acceleration, then the Aisin automatic transmission has an indicator no worse than on the mechanics.
• Reliability. These boxes show a good resource in adverse conditions. So, before a major overhaul, such a car can run about 400 thousand kilometers.
• Simple design. This allows not only to save on repairs, but also to perform independent maintenance. So, replacing the ATP fluid can be done by hand. It is enough to buy the appropriate oilfor automatic transmission "Aisin". But also do not forget about the cleaning element. Along with the oil, the filter in the Aisin automatic transmission also changes.

Some cons

With frequent loads and the use of a sports mode, the automatic transmission torque converter clutch may become unusable. Also changes its color and oil. It turns from red to black. fluid contamination must not be allowed. In the event that the piston friction has been worn down to iron, the oil is saturated with an adhesive composition. This negatively affects the operation of the valves of the hydraulic block. The spools can stick both “hot” and “cold”, preventing the solenoids and springs from opening fluid channels in time. This leads to a loss of traction and increased wear on the clutches in the packs.

Maintenance

The manufacturer recommends changing the oil in the automatic transmission every 100 thousand kilometers. And if the car is used in extreme conditions (frequent traffic jams and driving at low temperatures), this period must be halved. Replacement requires 7 to 10.5 liters of ATP fluid. A fine filter is also required. It is felt, with a double membrane. It should be changed at the same frequency as the gear oil itself.

Diagnosis

How to understand that the box needs repair? Several third-party signs can report this:

• Jerks when trying to pick up speed. This usually happens when shifting from first to second gear.
• Kicks while parking. It is felt when the driver moves the box selectorfrom "Parking" to "Drive" mode. The car seems to take off.
• Loss of acceleration dynamics. This manifests itself in slipping in one of the gears, or in several at once.

You also need to monitor the oil level. If it is not enough, it will lead to a drop in pressure in the system, as well as overheating of the transmission.

Repair

How are the above faults repaired? For this, a replacement is made:

• Sealing elements. These include seals and gaskets. This is a mandatory procedure that must be done if the clutches burn out. Contaminated oil, saturated with wear products, leads to wear of Teflon rings. They are manufactured to certain tolerances. In case of the slightest wear, the ATP fluid begins to “poison”
• Frictions. They are not subject to restoration and change in the kit. In the event that the combustion of steel discs has been diagnosed, the oil also changes, as it becomes contaminated with refractory resins. New steel rims are also being installed.
• Solenoids. Their replacement is carried out only after disassembling the hydraulic unit and troubleshooting. The planetary gear is also examined. It may also require replacement, but very rarely.
• Pan gaskets. This is the most harmless operation. Usually required after an oil change, when the pan itself was dismantled in order to install the filter.
• Pump sleeve and stuffing box. These elements can break over time. This is facilitated by constant vibrations from the friction clutch.lockup clutch.

Repair features

In the case of work of medium complexity, the valve body is removed and repaired. This operation requires adding oil in a volume of 2.2 liters. During the overhaul, the box is dismantled with the repair of the torque converter. The clutch package and completely oil are also changed. In the case of minimal repairs, the pan is removed, the solenoids are cleaned and the filter is changed. At the same time, about one liter of oil is added.

Important: if there is insufficient pressure in the box from a small amount of oil, this will lead to the combustion of the clutch packs.

The repair procedure itself should be performed at specialized services. No matter how simple an automatic transmission is, restoring it is not an easy operation. It is important not only to install the parts correctly, but also to correctly assemble the box.

Electronics

In addition to the mechanical part, with the Aisin 6-speed automatic transmission, there may also be electrical malfunctions. So, the box has weak wiring harnesses, which may cause the control signal to disappear.

In this case, specialists conduct computer diagnostics and read all errors. In "running" cases, only the replacement of the electronic control unit can help. But in most situations, repairs are limited to replacing a set of electrical regulators. These include solenoids:

• Line pressure regulation.
• Clutch shift quality.
• Torque converter lockups.

If you drive for a long time with such a malfunction, it will burn the discs and cause a problem with the rest of the hydraulic plate solenoids.

Other malfunctions

Automatic transmission "Aisin" has weaknesses. It's an oil pump and a seal leak. If this problem is not corrected in time, this will lead to wear of the pump bushing. The latter may also soon become unusable. Its malfunction is accompanied by a characteristic sound in the transmission area. At the same time, the solenoid for blocking the hydraulic transformer of the Aisin automatic transmission wears out.

Another problem that occurs with these boxes is plungers-spools. They are in the design of the hydraulic plate itself. Their wear can cause unstable operation of the transmission in different modes.

Summing up

So, we found out what the Aisin automatic box is. In general, this transmission is quite reliable. It does not have fragile nodes, as in the DSG or in the variator, and also more resistant to loads and overheats. But nothing lasts forever, so over time the box may require attention. Faults can be both mechanical and electrical. It is important to identify this at an early stage. Otherwise, one problem will lead to many others. It is also worth noting that the selection of solenoid valves for six-speed Aisin boxes is made according to the VIN number of the car.