Oscillation of the shift pressure control valve within its sleeve causes wear, which will allow Drive or Reverse pressure being routed to the B2, B1 or C2 clutch to exhaust or cross leak. This will result in shift complaints and burnt clutches.
Restore proper hydraulic control by replacing worn parts with the improved, drop-in Sonnax kit.
The shift pressure control valve in Aisin AW 55-50SN units is biased by spring force and shift control (SLS) fluid pressure. This valve regulates Drive and Reverse fluid pressure to control the apply of the second clutch (B2), the second coast clutch (B1) or the direct clutch (C2). The constant oscillation of the valve wears the cast aluminum sleeve, allowing Drive and Reverse fluid pressure to leak and cause shift complaints and burnt clutches. The drop-in Sonnax shift pressure control valve kit 59947-38K uses upgraded materials and annular grooves on the valve to correct the problem and prevent future wear.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
September 30, 2005
Topics: Diagnostics And Theory TransmissionRead Now
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A vacuum test at the port indicated fails to hold at least 18 in-Hg, or if visual wear is detected in the sleeve.