Complaints of no 4th or 5th gear, codes 734 and/or 735, and solenoid C codes can occur on the 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. The Sonnax 4-3 Pre-Stroke Valve Spring 56947J-S1 addresses these complaints. This spring is not used on 5R55W & S 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%.