Printpartsummary
Symptoms:
  • Code 628
  • Delayed lockup
  • No lockup
  • Shudder
  • TCC apply & release concerns
Cause:

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

Correction:

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

Bypass Clutch Control Plunger Valve Kit
  • 76948-04k_combo

  • Bypass Clutch Control Plunger Valve Kit

Small_76948-04k_combo Small_76948-04k

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

Bypass Clutch Control Plunger Valve Kit

Part No. 76948-04K

  • Sleeve
  • Plunger Valve

Complaint:

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

Cause:

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


Correction:

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.

Common complaints with AODE/4R70W/4R75W transmissions 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 offers a replacement bypass clutch control sleeve and plunger valve with a restricted oil flow orifice, 76948-04K.

  • 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.

Related Parts

Click here to view PDF if instructions do not appear below.

It appears you don't have a PDF plugin for this browser. Click here to view the PDF file.

Related Tech Articles

Contact a Sonnax Distributor to purchase this part.