September 30, 2005
Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits
Gregg Nader
When signal pressure is applied to the switch valve in listed Chrysler transmissions, the valve is shuttled to the full stroke position. In this position, the release circuit to the torque converter is vented and the apply circuit is opened to the line pressure. This moves the torque converter from the released or fluid coupling state to the lockup state. The apply pressure on the torque converter is equal to full line pressure.
Chipped and/or performance enhanced transmissions can reach line pressures of 250+ psi. This level of pressure can potentially deform or balloon the torque converter. This deformation can affect fluid performance, efficiency and durability.
Sonnax TCC apply limit switch valve kit 44912-36K limits the amount of pressure applied to the torque converter without affecting the line pressure or creating partial apply drivability issues.
The OEM calls this a TCC switch valve. The improved Sonnax version is called a TCC apply limit switch valve because, while it functions like the OE valve, it also limits the converter apply pressure.
September 30, 2005
Gregg Nader
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.