RC4A-EL Archives - Transmission Digest
Where Do They Go?

The RC4A-EL transmission, also known as the JR405E, is used in the States in the Mazda RX8 vehicle. It has a much broader use overseas. Since this is not a transmission that shows up on the bench regularly here, when a shop gets one we usually receive a call for help on placing the three tension springs shown in Figure 1.

A Balancing Act

There is very little information written about this transmission concerning the valve body and its associated hydraulic operations. For this reason ATSG has produced a Technician Guide that provides extensive information including valve-body mapping and a complete set of hydraulics. In the process of developing this guide, we discovered a unique way in which this unit controls clutch application. The high-clutch amplifier valve in the upper valve body (Figure 2) serves as a perfect example.