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  • Burnt Forward clutch
  • Burnt intermediate band
  • Low line pressure
  • High line pressure
  • Pressure control out-of-range codes
  • Delayed Forward
  • Delayed Reverse


Bore wear results in reduced feed pressure to overdrive, intermediate or low/reverse servos or the coast clutch.


Refurbish the valve bore and install the Sonnax oversized valve kit to restore proper hydraulic function and prevent future leakage. This Sonnax kit works in either modulator valve location.


Oversized PCA/PCB Modulator Valve Kit
Part No. 56947J-49K

You need this if... View Instructions

5R55N units commonly experience low line pressure and delayed engagements, typically resulting in pressure out-of-range codes, burnt forward clutches or intermediate bands. Bore wear at the VFS1 (PCA) and VFS2 (PCB) locations allows modulated line pressure to exhaust instead of feeding the overdrive, intermediate or low/reverse servos or the coast clutch, causing the complaints and damage. Install Sonnax PCA/PCB modulator valve kit 56947J-49K after refurbishing the bore to restore hydraulic control and optimum line pressure feed to affected circuits. Hard anodized material and annular grooves provide a long lasting repair that can beused in either location.

  • Critical valve spools incorporate annular grooves for better hydraulic centering and reduced leakage and wear
  • Works in either modulator valve location
  • Valve
  • Plug
  • Spring

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
  • 56947j 49k combo1
  • 56947j 49k combo2
  • 56947j 49k

You need this if...

A vacuum at either port indicated fails, or if visual wear is detected at the inboard overlap valve bores.

  • 56947j 49k test