• Code 734, 735
  • Solenoid C Code
  • No 4th
  • No 5th


Breakage of the 4-3 pre-stroke valve spring prevents proper valve function.


Replace with the reduced-stress Sonnax 4-3 pre-stroke valve spring.


4-3 Pre-Stroke Valve Spring
Part No. 56947J-S1

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Complaints of no 4th or 5th Gear, codes 734 and/or 735 and solenoid C codes can occur on the Ford 5R55N due to a broken 4-3 pre-stroke valve spring. The 4-3 pre-stroke valve controls the apply and release rate of the intermediate servo and direct clutch, which should be applied in 4th and 5th Gear. Sonnax 4-3 pre-stroke valve spring 56947J-S1 addresses these complaints. This spring is not used on 5R55W & 5R55S units.

  • Spring is made from chrome-silicon alloy, which allows higher working stresses than typical music wire spring material
  • Spring configuration reduces operating stresses at the critical regulating positions of the valve by 8%

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 5R55N Valve Body Layout

Ford 5R55N Valve Body Layout
  • 5R55N 4-3 Pre-Stroke Valve Spring 56947J-S1
  • 5R55N 4-3 Pre-Stroke Valve Spring 56947J-S1