The Sonnax Performance Pack for GM 4L60-E, 4L65-E and 4L70-E transmissions is a must-have for any heavy-duty vehicle and the very best foundation for high-performance racing. All components work together to carefully tune line pressure, accumulator pressure and shift calibration. It’s the ultimate way to get an impressive transmission that responds to throttle and increased load with quick, firm shifts.
Features:
Consistent, firmer shifts under load without sacrificing low-speed drivability or guessing on calibration
Faster pressure increase and higher overall pressure for greater clutch/band holding power
Three ultra-reliable, patented, billet pinless accumulator pistons
Unique 1-2 accumulator spring combination for shifts with character
Improved high RPM pressure
Third accumulator valve gets the 2-3 right the first time, every time
Durable parts target commonly worn areas and prevent future damage to the accumulators and separator plate
The only way to eliminate PWM function without over-pressurizing converters (optional)
Kit Contents:
1-2 Accumulator Valve Shim
TCC Pressure Limiter Valve & Spring Optional, eliminates PWM/EC3 function