Repair of solenoids of the control unit TC-SST \ Power Shift 6

Automatic transmission 6DCT450 \ 470 PowerShift developed by GETRAG Corporate Group, belongs to the class of boxes with double wet clutch. The transmitted maximum torque of 450 \ 470 Nm is distributed by the dual-clutch system to six front and one rear gear. The automatic transmission is installed on front-wheel-drive vehicles with a transverse engine arrangement. The mechanical part of the box is controlled by the electrohydraulic block TCM (Transmission Control Module):

The lubrication system 6DCT450 \ 470 is based on one oil circuit, i.e. The oil used in the mechanical part of the box is also the working fluid for the TCM unit. This feature in most cases becomes the cause of failure of hydraulic unit solenoids. During the operation of the mechanical part of the box, there is a wearout of the friction clutches, the destruction of the moving parts and the dying of the surfaces of the gears. The oil filter system of the box does not completely remove the wear products, leaving dust of fine fractions. Dust mixed with oil clogs the body of the solenoid, which leads to premature failure.

Faulty hydraulic unit solenoids cause the following faults of the automatic transmission:

- low pressure in hydraulic control system of automatic transmission

- no activation, or unclear switching of gears

- shocks during shifting

There may be diagnostic errors

P0766 Seized when SSD is off. Improperly adjusted or wedged solenoid D

P0771 SSE perfomance or stuck off. Improperly adjusted or wedged solenoid E

To determine the efficiency of the solenoid, a special diagnostic stand is used.

Unstable operation, the presence of flat areas - a solenoid jam, at this point in the running automatic transmission can be impacted or do not turn on the transmission.

The graph of the failed solenoid (photo from the stand).

Solution.

The failed solenoids are to be replaced or restored. The method of solenoid restoration was developed by the specialists of the company Maktrans on the basis of many years of experience in servicing hydraulic assemblies. Ultrasonic cleaning is used to clean the solenoid from dust-oil contamination. The Skymen JTS floor washing machine is equipped with a 360 liter stainless steel bath. The ultrasonic generator with power adjustment ensures the process of thorough cleaning of solenoids from oil and other small particles (shavings, soot, dust). The sink is capable of operating in a continuous mode and is equipped with a fluid circulation system with an oil filter. It is also possible to use the Everest Elektromekanik ESP washer for high-quality washing and degreasing of solenoids.

During the ultrasonic cleaning, the solenoids of the cooling system and the main pressure are completely restored, the clutch solenoids are replaced in half with new ones. After ultrasonic cleaning, the solenoid is tested for compliance with the operating parameters.

At the end of testing, the restored solenoid is installed in the hydroblock. Further, the operation of the automatic transmission is tested on the fly.

Result.

Recovered solenoids, correspond to the performance of solenoids for automatic transmissions 6DCT450 \ 470. The service life of the solenoid after recovery corresponds to the life of the new solenoid, at a relatively lower cost.

Relatively recently, we tested the clutch DCT Stage 3 on the car AUDI RS5 with a torque bracket 1000 + Nm. In Stage 3, there were 8 clutches on a small package and 7 on a big one.

In the DCT Stage 3 HD whale I upgraded the basket considerably and I managed to put 9 + 9 DCT clutches. This solution is the most powerful in the market and by calculations should keep 1200+ nm. of torque

That is why we made the kevlar friction couplings for your beloved TC-SST! Kevlar friction couplings have higher coefficient of friction and they are not afraid of high temperature.

All owners of Eco X with the preselective robotic gearbox ТC-SST have heard about the unreliability of clutch coupling. I also purchased my Evo with dead coupling. The car would twitch at start and the coupling would sometimes skid. As the factory or tuned clutch costed a lot of money, I tried to resolve the problem in a different way.