TW40E Transmission parts, repair guidelines, problems, manuals

Transmission general data

The 4-speed automatic transmission A174 (TW-40) belonging to the "micro" class with a rear drive was designed by Aisin in 1998 on the basis of 3-speed predecessor А172. After testing and update, this transmission was installed on Suzuki Jimni, Escudo, Avery (Landy) with engines from 0.7 up to 1.3 liters. This automatic transmission is considered to be a modern, economical and “invincible” unit for the minimum torque (up to 120 Nm). Americans had been using TW-40E on Ford Pronto with 3-cylinder liter engine until 2007.

Technical issues and repair guidelines

For reassembly of the A174 unit repair specialists order the repair kit of gaskets and seals, clean the valve body and replace spare parts, and rebuild the torque converter. Transmission experts assume that it is necessary to replace all friction clutches (soaked with oil combustion products) in transmissions operating with burnt oil.

The valve body design of this transmission includes "On-Off" solenoids (responsible for gear shifting and the torque converter lock-up operation), and a big EPC solenoid. Solenoids are adjusted quite accurately and ensure the torque converter actuation without a hard slippage. Therefore the torque converter does not overheat or smudge solenoids too much, allowing solenoids to operate for quite a long time. Sometimes problems occur in wiring of solenoids.

In the process of complete reassembly of А174/TW-40E, transmission specialists replace the following repair kits with the aim to prolong the operation period of the unit:

- Kit of steel discs TW-40E

- Kit of traversing pistons (6 pieces)