Subaru R4AX-EL

Transmission general data

The 4-speed automatic transmission Subaru 4EAT was manufactured in 1988 (EC8 = R4AX-EL). This transmission is related to the F-4EAT transmission model manufactured by Jatco. The modification released in 1999 was replaced the previous EC8 version on almost all popular Subaru models. This transmission was installed not only on low-powered Impreza and WRX, but also on middle class Forester and Outback with 2-2,5 liter engines, and even on powerful Legacy model with the engine capacity of 3 and 3.5 liters.

Technical issues and repair guidelines

Subaru vehicles with this transmission rarely come to transmission repair shops. In terms of maintenance services, this transmission is very similar to Jatco transmnissions. The 4EAT unit is a very reliable and simple system with special settings which do not allow drivers to overload prone-to-damage parts with a high degree of safety.

Overhauls usually consist of the reassembly procedure with replacement of the filter and repair kit of gaskets and seals. A kit of friction components is also commonly ordered by transmission specialists together with the abovementioned components. If the transmission operates for a long time with burnt fluid, then all steel discs get replaced with frictions. The external filter protects the valve body and solenoids from contaminated ATF, which appears because of the worn friction lining of the torque converter. Specialists recommend to replace it together with the engine oil filter on cars where the mileage parameter enxceeds 100 thousand kilometers, especially after a hot summer. The valve body unit of this transmission was updated in 1998 (type 2) and in 2001. These components are quite durable and require only timely cleaning.

If the transmission is overheated and has leakages through the pump seal of the torque converter and oil rapidly gets contaminated after the ATF, then the torque converter lock-up clutch is likely to wear out, and as a result damages the wheel hub. The torque converter is repaired and the valve body gets cleaned from the dirt, which appears from the damaged friction, and the overhaul kit is replaced. The first standard overhaul of the car with high mileage always includes replacement of pistons with frictions and a solenoid of linear pressure. The resource of this transmission is above the average and after a proper overhaul may be increased for several years.