4L60E-HD2

This 4L60E-HD2 Reprogramming Kit fits 1993 to 2015 General Motors vehicles equipped with the 4L60E, 4L65E and 4L70E automatic transmission. Common complaints on this transmission are TCC slip or shudder, code P1870 or P0894, harsh 1-2 shift, double bump shifts, 2-3 flare up, burnt 3-4 clutch plates as well as inconsistent pressure boost problems.

The torque converter clutch regulator valve bore is very prone to wear causing the TCC slip complaints and related code. The TCC slip code leads to the harsh 1-2 upshift as the ECM recognized the TCC slip and commands high line pressure to avoid further TCC slippage and damage. The 3-4 clutch plate failure as well as the 2-3 flare up complaints are caused by an inconsistent pressure boost and poor overall calibration of the shift accumulation system.

Features and benefits:

This TransGo Reprogramming Kit includes valve body, servo, pump and accumulator components and modifications designed to deliver increased durability while providing firm shifts as well as a more efficient TCC apply. It includes components as well as modifications that recalibrates the entire accumulation system, clutch and band feed orifices. These changes work in concert with an aggressive line pressure curve to greatly improve the overall durability and shift feel of the transmission. . Furthermore, the included drop-in USA-made TCC isolator and regulator valve features longer lands which restores the hydraulic integrity of the circuit by utilizing previously unused and therefore unworn areas of their bore. Lastly, on 1993 to 2008, the gear command feature will allow for full gear lever controlled downshifts 3^rd through 1^st gear as well as holding manual 1^st or 2^nd gear to any speed or RPM.

This kit can be installed while the transmission is in the vehicle on 1993-2006 models only without the input speed sensor. 2007 and later models equipped with the input speed sensor require transmission removal. This kit also includes #7-CS 3-4 clutch piston return spring kit for the input drum which reduces centrifugal 3-4 clutch apply and failure in 1^st gear at 5500 RPM or higher, transmission removal required.

Corrects/Prevents/Reduces:

• TCC slip or shudder
• Code P1870 and P0894
• Harsh 1-2 shift
• Long soft shifts
• Double bump or slide bump on the 1-2 shift
• 2-3 flare up
• 2-4 band failure
• Burnt 3-4 clutch plates
• Burnt forward and low/reverse clutch plates
• Pump slide and valve bore wear

Includes:

• Second servo piston spring, two shims and two O-rings
• (2) 1-2 accumulator springs, spring seat and three spacers
• 3-2 Downshift valve spring
• Actuator feed limit valve spring
• (2) 1-2 accumulator valve springs
• USA-made hardened steel 1-2 shift valve and spacer
• Low valve spring
• USA-made hardened TCC regulator and isolator valve, spring and installation bolt
• (2) Pressure regulator valve springs and spacer
• .500” boost valve, bushing and snap ring
• EPC screen wire spacer and oversized 1-2 checkball
• (2) Drill bits
• (2) Reverse input piston orifice cup plugs
• 3-4 accumulator spring
• (2) Valve body gaskets
• Pan gasket
• 3-4 clutch return springs and orifice capsule
• Forward clutch return springs and installation washer