NEW billet aluminum pinless forward accumulator piston   Fits the 4L60E, 4L65E, 4L70E, 4L75E transmission   Sonnax Part Number:  77987-01K   Stock, these transmissions had plastic pistons that break, burning up your transmission. This piston is very easy to install and is recommended when doing any shift kit. This can even be done if you just have the pan off for a fluid change. The valve body doesn't have to come out for this to be installed.   This kit comes with the piston, seals, and two check balls.   Check out our eBay Store for more great deals on torque converters, shift kits and other transmission parts.