In Aisin AW 55-50SN and 55-51SN units, bore wear at the lockup control valve in listed units results in loss of torque converter clutch control. The TCC can remain applied transferring shift shock, or loss of lockup control can result in RPM fluctuations. Sonnax oversized lockup control valve and boost valve kit 59947-29K restores control of the TCC. Proper TCC control eliminates the shift shock and RPM fluctuations associated with a worn lockup control valve.

• Hardcoat anodized aluminum valves combat premature wear
• The boost sleeve is highly wear-resistant to increase life