Symptoms:

  • TCC apply concerns
  • TCC codes
  • Delayed engagement
  • Burnt converter

Cause:

Wear at the TCC back pressure valve bore prevents proper pressure from reacting on the cover side of the converter clutch, resulting in apply compaints.

Correction:

Refurbish the valve bore and install the Sonnax oversized TCC back pressure valve kit to restore proper hydraulic function and prevent future wear.

Warning:

Required tool kit F-56947J-TL63 is no longer in production. Check with your distributor for availability.

5R55N

Oversized TCC Back Pressure Valve Kit
Part No. 56947J-63K


You need this if... View Instructions Find a Distributor

In Ford 5R55N units, as the valve bore wears at the inboard spool, converter clutch back pressure escalates with increased temperature and the back pressure valve does not stroke, preventing the TCC from applying fully. Wear at the outboard spool bore allows converter clutch pressure to exhaust, which reduces correct release pressure and allows the converter clutch to contact the cover prematurely. Sonnax oversized TCC back pressure valve kit 56947J-63K will restore proper hydraulic function and prevent future wear.

  • Valve
  • Spring
  • End Plug

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 Oversized TCC Back Pressure Valve Kit 56947J-63K
  • 5R55N Oversized TCC Back Pressure Valve Kit 56947J-63K

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

5R55N Oversized TCC Back Pressure Valve Kit Vacuum Test Locations
5R55N Oversized TCC Back Pressure Valve Kit Vacuum Test Locations