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  • Damaged valve body casting
  • Low spring rate on 2.3L TCC regulator valve
  • Code P0741
  • Low TCC apply pressure


Incorrect spring rate for the TCC regulator valve.


Recalibrate TCC apply to 4.0L rate.

4R44E, 4R55E, 5R44E, 5R55E

TCC Regulator Valve Spring Kit
Part No. 37947-46K

The 2.3L TCC regulator valve has a lower spring rate and lower apply pressure than the 4.0L. If the incorrect core is installed or the springs have been damaged, the TCC apply pressure is reduced and slippage occurs. The springs in the Sonnax kit 37947-46K have been designed to match the 4.0L calibration. The kit can be used to replace weak, broken or lost springs in 4.0L applications or to convert a 2.3L valve body core for use in a 4.0L application.

  • Direct replacement 4.0L springs salvage or upgrade the valve body.
  • Spring kit allows conversion of 2.3L valve body to 4.0L application.

Not recommended for usage in 2.3L applications as firmer apply will result.

  • Outer Springs (5) White
  • Inner Springs (5) Plain

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.

Ford 4R/5R44E, 4R/5R55E Valve Body Layout

Ford 4r 5r44e thumb

September 30, 2005

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  • 37947 46k combo
  • 37947 46k