Symptoms:

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

Cause:

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

Correction:

The tightly toleranced, Sonnax lockup control valve kit 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 AF23/33 and RE5F22A units.

You need this if... View Instructions Find a Distributor

In Aisin AW 55-50SN and 55-51SN units, the original equipment lockup control valve sleeve is prone to significant wear due to constant oscillation of the plunger valve, resulting a multitude of converter complaints. Converter feed pressure from the secondary pressure regulator valve is directed in part to this plunger valve assembly and becomes converter apply pressure. The plunger valve aids in correctly positioning the inboard lock up control valve to regulate converter apply. If this sleeve is worn, converter apply pressure is reduced and the converter may not fully apply. Sonnax lockup control valve kit 59947-03K restores proper hydraulic clearances and prevents valuable converter apply pressure loss.

  • Sleeve is manufactured from highly wear-resistant billet aluminum
  • Hardcoat anodized aluminum valve combats premature 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, 55-51SN Valve Body Layout

Aisin AW 55-50SN, 55-51SN Valve Body Layout
  • 55-50SN, 55-51SN Lockup Control Valve Kit 59947-03K
  • 55-50SN, 55-51SN Lockup Control Valve Kit 59947-03K

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

55-50SN, 55-51SN Lockup Control Valve Kit Vacuum Test Locations