1993 to 2015 General Motors vehicles equipped with the 4L60E, 4L65E and 4L70E automatic transmission over time wear out the pressure regulator boost valve assembly in the pump. As a result, the transmission will not have the required main line pressure under load.
The computer tailors the line pressure rise in accordance with the calculated load. It does this by varying the pressure control solenoid current, which in turn increases the main line pressure accordingly. Adequate main line pressure rise is required to provide enough clamping force under all load conditions to prevent slipping, as well as to achieve proper shift quality. Consequently, a compromised boost valve may cause complaints of soft shifts, flare shifts, burnt frictions and a burnt lock-up clutch. These complaints can also be accompanied by a wide variety of gear ratio, shift and solenoid performance codes.
Features and benefits:
TransGo drop-in replacement boost valve and bushing assemblies provides you with an economical and durable direct replacement for the OEM assembly that is prone to wear. The unique proprietary boost valve assembly design replaces either the OEM long or short type.
Note that up to March 2005 the kit can be installed in the vehicle. However, in March 2005, General Motors gradually started adding an input speed sensor in this transmission which inhibits access to the boost valve assembly. On those with the added input speed sensor, transmission removal is necessary to access the boost valve.
- Insufficient line rise
- Soft, slipping or flaring shifts
- Burned friction material
- TCC slip