Shift Accumulation
3-4 Accumulator
The fourth band fluid is also routed to the 3-4 accumulator piston. Fourth band fluid pressure moves the piston against a combination of spring force and 3-4 accumulator feed fluid pressure. This action absorbs initial fourth band fluid pressure in order to cushion the intermediate and Fourth band apply. The movement of the 3-4 accumulator piston forces some fluid out of the accumulator.
3-4 Accumulator Valve
The 3-4 accumulator feed fluid which is forced from the 3-4 accumulator unseats the #7 checkball and the fluid is routed back to the 3-4 accumulator valve. This pressure forces the 1-2/3-4 accumulator valve against a combination of spring force and torque signal fluid pressure in order to regulate the exhaust of excess accumulator fluid. This regulation provides additional control for the intermediate and fourth band apply.