• Slip codes
  • High TCC slip RPM at increasing load
  • Overheated fluid
  • Damaged valve body casting


Plunger valve related sleeve wear reduces converter apply pressure and TCC slippage increases. OE clips raise burrs on the sleeve, which drag a groove into the casting bore during removal, allowing hydraulic leakage.


Sonnax oversized TCC modulator plunger valve kit restores proper hydraulic clearances so fluid pressure can position the TCC modulator valve to fully apply lockup. The increased ratio assembly provides a firmer and quicker lockup feel. The new design retainer prevents burr issues on the sleeve that create additional hydraulic leakage.

5R55S, 5R55W

Oversized TCC Modulator Plunger Valve Kit
Part No. 56947J-81K

Increased Ratio

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

Some common complaints associated with Ford 5R55W and 5R55S are high TCC slip RPMs under increasing loads, slip codes and converter apply or release concerns. These complaints are often caused by wear at the ID of the TCC modulator plunger valve sleeve, due to constant oscillation by the pulse width modulated TCC solenoid. This plunger valve positions the TCC modulator valve, which feeds line to the apply circuit, which controls slip rate. Wear of the sleeve will allow the TCC slip rate to continue to rise, and could prevent full lockup. Another path for hydraulic leakage can be created by the OE retaining clips raising a burr on the TCC modulator sleeve, which gouges the casting bore during disassembly.

Sonnax oversized TCC modulator plunger valve kit 56947J-81K restores hydraulic integrity to the TCC solenoid circuit with precisely toleranced parts. The elevated modulated pressure will not raise apply pressure to the point of TCC piston fatigue, and will result in firmer TCC apply and reduced slip RPM in heavier use applications. A new design retaining clip prevents future burr creation on the sleeve that results in valve casting damage and leakage during disassembly.

  • Increased ratio provides a firmer and quicker lockup feel
  • Hardcoat anodized aluminum valve combats premature wear
  • High-grade aluminum sleeves are extremely wear-resistant
  • New design retainer eliminates burr creation
  • Valve
  • Sleeve
  • Retainer
  • 56947j 81k combo
  • 56947j 81k

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.

  • 56947j 81k test