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  • Burnt converter
  • TCC apply & release concerns
  • TCC codes


Continuous oscillation of the steel lockup control plunger valve wears the inside of the cast-aluminum sleeve bore, allowing converter apply pressure to exhaust and preventing proper control of the lockup control valve


The tightly toleranced, drop-in replacement Sonnax valve and sleeve assembly restores proper hydraulic clearances and uses upgraded materials to prevent wear.

55-50SN, 55-51SN

Lockup Control Valve Kit
Part No. 59947-03K

Also fits AW55-51SN, AF 23/33 and RE5F22A units.

You need this if... View Instructions
  • Sleeve is manufactured from highly wear-resistant billet aluminum.
  • Valve is made from hard-coat anodized aluminum to prevent wear.
  • Salvages costly cores with minimal labor.
  • Eliminates the need for expensive OE valve bodies.
  • Valve
  • Sleeve

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.

Aisin AW 55-50SN Valve Body Layout

Aw55 50sn vbl thumb
  • 59947 03k combo
  • 59947 03k

You need this if...

A vacuum test of the sleeve assembly (while in the bore at the outboard converter apply feed port and TCC signal oil port as indicated) gives less than 18 of vacuum, or if a Wet Air Test at the same locations results in leakage at the neighboring exhaust ports on the opposite side of the casting.

  • 59947 03k test