• Loss of fuel economy
  • Overheating
  • TCC apply & release concerns
  • TCC codes
  • TCC lining failure


Excess wear in the converter relief valve bore allows critical converter charge pressure to exhaust.


Recover hydraulic control and restore proper converter function by reconditioning the bore and installing Sonnax oversized converter relief valve kit.


Oversized Converter Relief Valve Kit
Part No. 74846-08K

You need this if... View Instructions Find a Distributor

Common problems associated with Mazda F4EAT, F4A-EL and FA4A-EL transmissions are overheating, TCC apply and release concerns, TCC codes and lining failure. These issues can be caused by excess wear at the converter relief valve. The relief valve controls TCC flow and pressure, and this wear allows fluid to escape the circuit, negatively affecting converter operation.

Reconditioning the bore and installing Sonnax oversized converter relief valve kit 74846-08K restores hydraulic integrity for proper converter function. The hardcoat anodized aluminum valve combats premature wear.

  • Valve
  • Spring
  • 74846 08k combo
  • 74846 08k

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

  • 74846 08k test