Sonnax 4L60E-LB2 Line Pressure Booster Kit for 4L60E 4L65E 4L70E Late Style

The Sonnax 4L60E-LB2 line pressure booster kit is designed for late-style GM 4L60-E, 4L65-E, and 4L70-E automatic transmission pumps. This performance upgrade kit combines a large ratio boost valve assembly with a stronger pressure regulator spring to deliver progressive hydraulic pressure increases as driving conditions become more demanding.

Key Features:

• Large ratio boost valve with short 1.810-inch sleeve for late-style pumps
• Pressure regulator spring approximately 10% stronger than OE
• Provides progressive pressure increases under load while maintaining smooth low-speed operation
• Achieves shorter shift times and increased torque capacity without creating low-speed harshness
• Delivers crisp, clean shifts without harsh engagement
• Includes boost valve assembly, pressure regulator spring, and two O-rings

This kit provides precision pressure control with modest pressure increases at the low end and high-end pressure equal to or greater than other aftermarket solutions. The result is improved clutch holding capacity, increased durability, and normal light throttle shifts with smooth coastdown characteristics. For early-style pumps with 1.907-inch long sleeves, use Sonnax 4L60E-LB1 instead.