sonnax-black Facebook-color LinkedIn-color maillink printlink r_and_r_only SERVOFIX-logo-web Twitter-color VBFIX-logo-web video-logo-web warranty_only Youtube-color


  • Shudder
  • Code 628
  • No lockup
  • TCC apply & release concerns
  • Delayed lockup


Too much oil to the bypass control valve plunger, or wear at the control sleeve.


The smaller orifice in the Sonnax sleeve allows TCC oil to stroke the bypass valve more quickly. The improved plunger and sleeve replace worn components that are leaking converter charge oil to exhaust.

4R70E, 4R70W, 4R75E, 4R75W, AODE

Bypass Clutch Control Plunger Valve Kit
Part No. 76948-04K

You need this if... View Instructions

Common complaints with listed Ford units include delayed lockup, shudder, no lockup or converter codes. When too much oil is routed to this plunger valve, the bypass valve has slow reaction from MCC/TCC solenoid oil. If there is excessive wear at the plunger valve, regulated converter charge oil can leak to exhaust. Because this regulated converter charge oil is always present, either as release or apply pressure, severe leakage at the sleeve can result in TCC slip or no apply condition. Sonnax bypass clutch control plunger valve kit 76948-04K restores hydraulic integrity and will eliminate these problems.

  • The single .030" orifice is much smaller than the OE size, allowing the bypass clutch control valve to properly stroke to the TCC apply position.
  • This eliminates the need to modify the plunger feed hole in the separator plate, which is a common industry adjustment.
  • Highly wear-resistant sleeve and hard-coat anodized plunger valve eliminate converter charge oil loss.
  • Sleeve
  • Valve

November 14, 2016

Ford 4R70E, 4R70W, 4R75E, 4R75W, AODE Vacuum Test Guide

Topics: Vacuum Test Guides Vacuum Testing Transmission Ford 4R75W Transmission 4R70W Transmission AODE Transmission 4R70E Transmission 4R75E Transmission

Read Now

September 30, 2005

Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits

Gregg Nader

Topics: Diagnostics And Theory Transmission

Read Now
  • 76948 04k combo
  • 76948 04k

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.

  • 76948 04k test