• Delayed engagement
  • Low line pressure
  • High line pressure
  • Overheating
  • Low cooler flow at idle


Debris and constant oscillation of the pressure regulator valve can create scratches or wear on the critical valve spools.


Restore hydraulic function of the pressure regulator valve by installing direct replacement Sonnax valve with or without the related Sonnax sleeve, depending upon original failure mode.

4R44E, 4R55E, 5R44E, 5R55E

Pressure Regulator Valve
Part No. 37947-54

OE Size

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

Debris and constant oscillation of the pressure regulator valve in listed Ford units can create casting bore wear and scratches on the critical valve spools. This allows valuable line pressure to exhaust and diminishing converter apply pressure, resulting in incorrect line pressure, delayed engagements and converter issues that lead to overheating.

Sonnax pressure regulator valve 37947-54 is a direct replacement for unworn bores containing valves with noticeable spool scratches. For worn bores containing valves with significant scratches, this direct replacement 37947-54 valve should be used in conjunction with the sleeve in Sonnax kit 37947-05K (reaming required).

  • Direct replacement valve for use in OE casting
  • Valve can also be used with sleeve from Sonnax kit 37947-05K
  • Hardcoat anodized aluminum valve combats premature wear

If bore is unworn, use Sonnax valve to replace damaged or scratched OE valve. If excessive bore wear is detected, use Sonnax valve in conjunction with Sonnax sleeve in 37947-05K. Worn/damaged OE valves used in a sleeve will not optimally restore hydraulic function.

  • 37947 54 combo
  • 37947 54

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if a visual inspection of critical valve spools finds excessive scratches.

  • 37947 54 in test