Sonnax 4L60 4L60E 4L65-E & 4L70-E Pinless Accumulator Piston Kit
Brand: Sonnax
Categories: Automotive, Replacement Parts, Transmission & Drive Train, Transmissions & Parts, Hard Parts

Complaints: Burnt clutches & bands and poor shift quality. 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 GM 4L60-E, 4L65-E and 4L70-E 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 77998-03K.

Pinless design eliminates the possibility of pin bore leakage
Dual seals stabilize and completely seal the bore and provide a tight seal
Steel balls plug existing pin bore in case or cover

Manufacturer: Sonnax Industries, Inc.
Brand: Sonnax
Item Weight: 1.6 ounces
Package Dimensions: 4.8 x 3.6 x 0.5 inches
Item model number: WO161131
Is Discontinued By Manufacturer: No
Manufacturer Part Number: 77998-03K
OEM Part Number: 62-77998-03K
ABPA Partslink Number: 62-77998-03K
Date First Available: February 7, 2013