Accumulator 4L60E 'pinless'

Accumulator 4L60E 'pinless' Pinless Accumulator Piston Aluminum D-Ring Viton® Seal PTFE Balls (2) Steel In 200-4R applications, this kit can only be used in the 3-4 accumulator location. In GM 200-4R, 4L60 and 4L60-series 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. Symptoms: Burnt clutches & bands 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.