Aisin Warner TF-70SC

Transmission general data

The 6-speed automatic transmission AT6 (TF-70SC) from Aisin Co was designed in 2006 for FWD Peugeot cars of the middle class with the engine from 1.6 to 2 liters. This transmission has the torque capacity of up to 220 Nm (according to Aisin). After a long testing this automatic transmission was launched in the mass production in 2009, but was produced not as actively as the TF80 transmission unit. It was developed for Peugeot-Citroen cars on the constructive basis of TF-80SC (AM6 High torque capacity- up to 400 Nm). Inner parts of this transmission are similar to TF60-SN. Aisin name is AWF6F25.

Technical issues and repair guidelines

The transmission AT6 has an electronic control integrated in the design of the transmission. One of the features of these automatic transmissions is the forced control of the torque converter lock-up. This feature, on the one hand, gives an increase in efficiency and rapid acceleration with fuel economy, but, on the other hand, it significantly loads the torque converter and the valve body. In previous versions of transmissions it led to the rapid wear-out of the valve body and the breakdown of solenoids. The transmission is designed as an "invincible" solution and operates till the old age of the car, when the transmission repair no longer makes sense. But violation of simple rules of operation for this automatic transmission can lead to the overhaul only after 150-200 thousand kilometers.

Repair procedures and typical problems

For the first overhaul specialists order the Repair kit of gaskets and seals. This repair kit is ordered mainly because of teflon rings, which wear out primarily from exploitation with contaminated oil and overloads.

The chain of malfunctions starts with the clogged valve body and solenoids, which do not transmit enough oil to the line of one of the packages, therefore the transmission shifts gears with a delay or a kick. One of the typical problems in modern 6-speed automatic transmissions, and in the TF-80SC in particular, is related to the valve body. The valve body is extremely sensitive to the friction suspension from the torque converter in the ATF. Frequent oil changes facilitate the valve body self-cleaning. But now the valve body itself has become almost invincible because all soft spots related to channels transmitting contaminated oil and the plunger with valves have become the part of the solenoid design.

It should be borne in mind, that the higher the wearout level of rings and rubber gaskets, the more ATF should be transmitted by the pump through valves of the valve body in order to compensate losses. Therefore solenoids operating in heavier oil current wear out much faster. For this reason, each reassembly and replacement of solenoids should be accompanied by replacement of spare parts.