Symptoms:

  • 4-3 Neutral
  • No 4th
  • Burnt OD band

Cause:

Wear at the inside diameter of the overdrive servo regulator boost valve sleeve due to constant oscillation allows valuable overdrive oil to leak.

Correction:

Install Sonnax replacement assembly to provide better sealing at all temperature ranges.

4R70E, 4R70W, 4R75E, 4R75W

Overdrive Servo Regulator Kit
Part No. 76948-29K

Fits '01-later units only.

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

Common problems in listed Ford units include are a burned overdrive band, loss of 4th Gear, and/or a 4-3-Neutral shift pattern. These problems can be caused by wear at the inside diameter of the overdrive servo regulator boost valve sleeve, due to constant oscillation. Excessive wear allows valuable overdrive oil to leak, preventing the proper regulation of the overdrive servo. Sonnax overdrive servo regulator kit 76948-29K maintains critical tolerances that re-establish the hydraulic integrity of the circuit.

  • Hardcoat anodized valve and high-grade aluminum sleeve resist wear.
  • Closely toleranced sleeve improves sealing.
  • Valve
  • Sleeve
  • 4R70E, 4R70W, 4R75E, 4R75W Overdrive Servo Regulator Kit 76948-29K
  • 4R70E, 4R70W, 4R75E, 4R75W Overdrive Servo Regulator Kit 76948-29K

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.

4R70E, 4R70W, 4R75E, 4R75W Overdrive Servo Regulator Kit Vacuum Test Locations