Sonnax Performance Pack HP-4L80E-01 upgrades GM 4L80-E and 4L85-E transmissions for maximum performance and durability in work/sport vehicles. Innovative components work together to precisely recalibrate pressures and shift accumulation, delivering firmer shifts under load without sacrificing low-speed drivability. To target common wear areas in the transmission, the kit includes many improved parts to repair damage, prevent future wear and improve reliability.
- Recalibrated shift accumulation, with tunability for great, heavy-duty shifts
Improved pump components minimize leaks, plus maintain pressure and lube under demanding use
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- The only way to eliminate TCC PWM function without over-pressurizing the converter
- Includes internal parts for setup and to prevent common failures
- Contents
- Line Pressure Booster Kit
- Lube Regulated Pressure Regulator Valve
- TCC Pressure Limiter Valve, Spring & Plug
- AFL Filter End Plug & O-Ring Kit
- Direct Clutch Dual Feed Plug
- Direct Clutch Dual Feed Aluminum Plugs (3) 2 Extra
- 1-2, 2-3 & 3-4 Accumulator Piston Springs (3)
- Checkballs (8)
Twist Drill .062"
Twist Drill .086"
Heavy Duty Case Bushing & Bearing Kit
Direct Housing Support Ring & Seal
Heavy Duty Intermediate Piston Spring Retainer Plate
Case Saver Retainer
Heavy Duty Clutch Retaining Ring Intermediate Clutch
Accumulator Valve Springs & Adjustable End Plug 2 Springs
Heavy Duty Direct Piston Return Springs (8)
Forward Clutch Hub Front Washer .078"
Reverse Servo Spacer Kit