December 20, 2023

AODE, 4R70W Series Bypass Clutch Control Valve Repair Options: When to Use Sonnax 76948-04K vs. 76948-64K

Tory Royce

  • OE lockup feel
  • Drop-in parts install quickly & easily
OE SleeveSonnax 76948-64KSonnax 76948-04K
OE Sleeve76948-64K76948-04K
4 Sleeve Orifices (.063")4 Sleeve Orifices (.063")1 Sleeve Orifice (.030")

  • OE lockup feel
  • Drop-in parts install quickly & easily
  • Firmer, quicker lockup feel
  • Drop-in parts require a few extra steps to install

It is common with Ford AODE, 4R70E, 4R70W, 4R75E and 4R75W units to experience TCC shudder, delayed lockup, no lockup or converter codes. This can often be attributed to wear at the bypass clutch control plunger valve and sleeve in the valve body.

Sonnax has offered plunger valve repair kit 76948-04K for some time, and it’s a great solution to address this wear. Compared to the OE valve design, however, the single .030" orifice in the Sonnax sleeve can create a more pronounced lockup engagement. You have the option of drilling an additional orifice in the sleeve if OE lockup feel is desired, but this and plate modifications on earlier units add extra steps to the installation process. An alternative repair was needed.

Featuring four .063" orifices in the sleeve to mimic the OE hydraulic design, Sonnax valve kit 76948-64K allows the bypass clutch control valve to match OE timing when stroking to the TCC apply position. This eliminates the need for drilling, which is particularly beneficial on ’96-later applications where engine lugging and harsh TCC apply can occur if the OE calibration is not observed.

So, for earlier units in which firmer, quicker lockup feel is desired, continue to use 76948-04K. For units in which OE calibration with no modifications is preferred, consider using 76948-64K. Both options are drop-in Zip Valve repairs that correct problems, guard against future wear and require no reaming to install.

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