4L60E, 4L65E, 4L70E

In 200-4R applications, this kit can only be used in the 3-4 accumulator location.

Symptoms:

• Poor shift quality
• Burnt clutches & bands

Cause:
Wear at the piston pin bore due to repeated reciprocation.

Correction:
The Sonnax patented pinless design with dual seals stabilizes the piston in the bore and provides improved sealing characteristics. Use of the Sonnax part eliminates the need for the pins.

In listed GM units it is common to have poor shift quality, burnt bands or clutches due to accumulator piston wear. Repeated reciprocation of the accumulator piston causes wear at the piston pin bore interface. After this wear reaches a critical point, fluid loss through the piston pin bore cannot be compensated due to lack of pump volume. In addition, the piston can get cocked and gall the accumulator bore due to the pin bore wear or the spring bottoming out. To prevent these conditions in the 1-2 or 3-4 accumulator bores, Sonnax offers pinless accumulator piston kit.

• Pinless design eliminates the possibility of pin bore leakage and the additional length stabilizes the piston to prevent piston cocking
• Dual seals stabilize and completely seal the bore and provide a tight seal even after thousands of cycles
• Steel balls plug existing pin bore in case or cover

Kit Contains:

• D-Ring Viton®
• Pinless Accumulator Piston Aluminum
• Seal PTFE
• Steel Ball .312" dia.
• Steel Ball .236" dia.

SONNAX Installation Instructions