Sonnax 5R55S 5R55W Transmission TCC Modulator Plunger Valve Kit 56947J-01K Some common complaints associated with a 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. The Sonnax assemblies restore 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. Increased ratio provides a firmer and quicker lockup feel. OE stock ratio restores original lockup feel. Precisely toleranced parts restore hydraulic integrity. Hard-coat anodized aluminum valves resists wear. High-grade aluminum sleeves are extremely wear-resistant. Note The valve bore inward of this TCC modulator sleeve wears rapidly. Always inspect for bore wear at the largest spool of the inner valve. Contents Sleeve Valve