4L60E 4L65E 4L70E Pinless Forward Accumulator Piston Kit Sonnax FWD, 1-2 and 3-4

Brand: Sonnax Interchange Part Number: S74927BK, S74927K Items Included: (3) Pinless Accumulators with Seals  Manufacturer Part Number: 77987-01K, (2) 77998-03K  Universal Fitment: Yes  Vintage Part: No Performance Part: Yes  4L60E 4L65E 4L70E Transmission Sonnax Pinless Accumulators Forward, 1-2, and 3-4 Accumulator Piston Kit  Part No. 77987-01K Dual Seal design In GM 4L60-E, 4L65-E and 4L70-E units it is common for the plastic forward accumulator piston to wear or crack. This causes a loss of fluid, resulting in delayed engagement, slips, burnt clutches and/or bands. Repeated reciprocation of the accumulator piston causes the piston pin bore to wear, while fluid loss through the piston pin bore or cracks causes forward clutch to slip. Sonnax pinless forward accumulator piston kit 77987-01K eliminates these problems. Dual seals stabilize and completely seal the bore, providing a tight seal even after thousands of cycles Pinless design eliminates the possibility of pin leakage