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5R55S, 5R55W

Line Pressure Booster Kit
Part No. 5R55WS-LB1

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Sonnax hydraulic line pressure booster kits contain stronger pressure regulator springs and large ratio boost valves designed to work together to provide progressive pressure increases as driving conditions become more demanding.

Our pressure regulator springs are approximately 10% stronger than OE and more conservative in impact than other aftermarket kit springs. Large ratio boost valves provide higher pressure incrementally and when it is needed the most. The combination of these springs and valves in a Sonnax kit gives you the best of both worlds: a modest pressure increase at the low end, with a high-end pressure that is equal to or greater than that of other aftermarket kit springs.

  • Achieve shorter shifts and increased torque capacity without creating low-speed harshness
  • Improved band and clutch holding capacity
  • Progressive pressure increase as driving conditions become more demanding
  • All the benefits of increased line pressure without overloading the pump at idle
  • Simple and affordable drop-in solution with no special tools or reaming required
  • Large Ratio Boost Assembly
  • Pressure Regulator Spring Large Dia.

September 24, 2010

The Prescription for Optimum Pressure

Topics: Diagnostics And Theory Transmission Chrysler 45RFE Transmission 545RFE Transmission 68RFE Transmission

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  • 5r55ws lb1 combo
  • 5r55ws lb1

Sonnax Line Pressure Booster Kits

Peace of mind for everyday customers pushing vehicles to the limit

Sonnax booster kit components are uniquely designed for precision pressure control. At low-end pressures, they deliver normal engagements, normal light throttle shifts and smooth coastdown shifts. When vehicles are pushed harder, components progressively increase pressure for improved clutch holding capacity and increased durability.

Learn more about Line Pressure Booster Kits