Aisin 55-50SN, 55-51SN secondary regulator valve bores are very active, and subject to wearing the casting bore. This valve regulates converter feed pressure according to throttle (SLT) pressure, and also is the primary distributor of lube flow throughout the transmission. Wear at the valve bore diminishes the valves ability to supply proper converter and lube pressure, resulting in converter related complaints and rapid bushing failure.

The Sonnax oversized secondary regulator valve kit 59947-16K restores proper hydraulic clearance after reaming with F-59947-TL16. The front spool of the Sonnax valve has been lengthened significantly, providing more support to prevent future wear.

• Salvages valuable core
• Improved valve support to reduce wear
• Improved converter feed and lube flow
• Hardcoat anodized aluminum valve combats premature wear