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  • Bushing wear
  • Overheated fluid
  • TCC apply concerns
  • TCC slip
  • TCC surge
  • Overheated converter


Continuous oscillation within the sleeve causes wear which prevents proper hydraulic control of the secondary pressure regulator valve.


Installing Sonnax boost valve and sleeve restores critical tolerances to bring back normal operating conditions.

09D, TR-60SN

Secondary Pressure Regulator Boost Valve Kit
Part No. 25741-36K

You need this if... View Instructions

Converter-related issues common in Aisin AW TR-60SN (VW/Audi 09D) transmissions are often caused by wear at the secondary pressure regulator valve boost assembly. The boost valve continually oscillates within the sleeve to help properly position the inboard secondary regulator valve. This movement is controlled by line pressure control solenoid fluid acting on the boost valve in response to throttle pressure. The secondary pressure regulator valve controls pressure to the converter and lube circuits, so wear at the boost assembly can create excessive TCC slip, TCC surge, bushing failures and overheated fluid and converters. Installing Sonnax secondary pressure regulator boost valve kit 25741-36K will restore proper hydraulic control and eliminate these issues.

  • 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 TR-60SN Valve Body Layout

Tr 60sn vbl thumb

September 30, 2005

Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits

Gregg Nader

Topics: Diagnostics And Theory Transmission

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  • 25741 36k combo
  • 25741 36k

You need this if...

A vacuum test at the port indicated fails to hold at least 18 in-Hg.

  • 25741 36k test