Features: 1.OE Number: The referencing OE number of this pinless accumulator piston kit are 77998?03K, 77987?01K, S74927BK, S74927K. 2.Fitment: The pinless forward accumulator piston kit is a replacement for 4L60E 4L65E 4L70E transmission, applicable for Forward 1?2, and 3?4, for Sonnax FWD 1?2 and 3?4. 3.Improved Transmission Performance: The pinless accumulator piston kit helps improve shift quality, prevent slips and burnt clutches, bands caused by accumulator piston wear. 4.Durable Design: The dual seals and pinless design eliminate the possibility of pin leakage, stabilizing the piston and preventing cocking for long lasting performance. 5.Easy to Install: The kit is designed for easy installation, providing a hassle free solution for improving transmission normal operation and performance. Specification: Item Type: Pinless Accumulator Piston Kit_x000D_ OE Number: 77998?03K, 77987?01K, S74927BK, S74927K_x000D_ _x000D_ Material: Aluminium_x000D_ Fitment:_x000D_ Fits for 4L60E 4L65E 4L70E Transmission Pinless Accumulators_x000D_ Applicable for Forward, 1-2, and 3-4 Accumulator Piston Kit_x000D_ Fits for Sonnax FWD 1-2 and 3-4 Note: Please double check the part number of your item, matching information is for reference only._x000D_ If you are unsure of the item, please contact us before buying to avoid unnecessary return, thanks!