200-4R, 4L60, 4L60-E, 4L65-E, 4L70-E

Enhanced Performance Accumulator Spring
Part No. 77704S

Package Quantity: 5

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Sonnax enhanced performance accumulator spring 77704S provides firmer 1-2 shifts for the enthusiast that appreciates quick, positive shift feel in listed GM units. The Sonnax spring design provides performance shift feel, but does not reduce accumulator piston travel. This allows for a firmer - but still cushioned - shift that minimizes shock to the band and shafts.

The Sonnax spring achieves the same effect as the common shop practice of replacing the OE 1-2 accumulator spring with the THM 350 direct accumulator piston spring. The Sonnax spring also may be used as a replacement for the THM 350 direct accumulator piston spring.

In ‘94-later units, install with the spring against the separator plate. See instructions for details.

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

GM 200-4R Valve Body Layout

GM 200-4R Valve Body Layout
  • 200-4R, 4L60, 4L60-E, 4L65-E, 4L70-E Enhanced Performance Accumulator Spring 77704S
  • 200-4R, 4L60, 4L60-E, 4L65-E, 4L70-E Enhanced Performance Accumulator Spring 77704S