4L80E, 4L85E

This Sonnax Performance Pack 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
• The only way to eliminate TCC PWM function without over-pressurizing the converter
• Includes internal parts for setup and to prevent common failures

Contains:

• 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

Sonnax Performance Pack - HP-4L80E-01