Performance Reprogramming Kit

The TransGo 4L60E-HD2 is a performance reprogramming kit designed for 1993-2015 General Motors vehicles equipped with 4L60E, 4L65E, and 4L70E automatic transmissions. It addresses common issues such as TCC slip, code P1870/P0894, harsh 1-2 shifts, 2-3 flare-ups, and premature 3-4 clutch plate failure by recalibrating the accumulation system and adjusting clutch and band feed orifices. The kit is not compatible with hybrid applications. The system includes a USA-made hardened TCC regulator and isolator valve with longer lands to restore hydraulic integrity. For 1993-2008 models, the included Gear Command feature allows the driver to maintain manual control over 1st, 2nd, and 3rd gear, enabling gear lever-controlled downshifts and hold-to-speed capabilities. Installation requirements vary by model year. On 1993-2006 models without an input speed sensor, the kit can be installed while the transmission is in the vehicle. 2007 and later models equipped with an input speed sensor require transmission removal. Additionally, the kit includes a #7-CS 3-4 clutch return spring set for the input drum to reduce centrifugal 3-4 clutch apply failure at high RPMs; installation of this specific component requires transmission removal.