Transtar Part Number: S89741PK
Transtar now carries the Oversized Pressure Regulator & Boost Valve Kit for the Aisin Warner 55-50 transmission. This item from Sonnax Industries, Inc. (59947-12K) is an upgraded aftermarket item that addresses the common occurrence of wear at the pressure regulator valve bore which results in harsh or soft shifts, delayed engagements, torque converter apply/release problems, and late shifts. This upgraded item features enhanced materials and includes the pressure regulator valve & sleeve and the boost valve & sleeve. Note that this is NOT a drop-in replacement item. To install the S89741PK, the use of Transtar Part No. T-F-59947-TL12 (Sonnax Part No. F-59947-TL12) tool kit is required and includes a reamer, guide pin, and reamer jig. Also required is Transtar Part No. T-VB-FIX which is the valve body fixture.