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  • Burnt clutches
  • Erratic line pressure
  • Low converter & lube flow
  • Overheating
  • Poor shift quality
  • TCC apply & release concerns


Relentless oscillation of line pressure control valve results in excess bore wear, causing erratic line pressure and/or restricting converter feed oil.


Recover hydraulic control and renew line pressure performance by reconditioning the bore and installing Sonnax oversized line pressure control valve kit.


Oversized Line Pressure Control Valve Kit
Part No. 126740-08K

You need this if... View Instructions

Ford 6R140 transmissions may exhibit multiple line pressure and converter-related problems due to excess wear in the line pressure control bore. Wear at the balance spool end allows critical fluid loss, resulting in high line pressure, harsh shifts, and overheating due to reduced cooler/converter flow. Wear at the outboard spool robs converter feed pressure and lowers line pressure, resulting in soft shifts and burnt clutches.

Reconditioning the bore and installing Sonnax oversized line pressure control valve kit 126740-08K restores hydraulic integrity for proper line pressure control and improved shifting in all ranges.

  • Oversized line pressure control valve and matched spring restore OE function
  • Hardcoat anodized aluminum valve combats premature wear
  • Annular grooves help center valve in bore to reduce future side-load wear
  • Minimal end plug-to-bore clearance with added O-ring for positive seal
  • Valve
  • Spring
  • End Plug
  • O-Rings (2) 1 Extra

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 6R140 Valve Body Layout

Ford 6r140 vbl thumb

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  • 126740 08k combo
  • 126740 08k

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. For accurate vacuum testing results, drop 1/8" dia. checkball in front of valve (bottom of bore) before testing. Ensure checkball is removed after testing!

  • 126740 08k test