Accumulators - 1-2

The 1-2 accumulator reduces shift shock when shifting from first to second gear. The accumulator piston is normally pressed to the right by line pressure. When there is a shift from first to second gear, the 2-4 band engagement pressure pushes the accumulator piston slowly to the left. As a result, the 2-4 band engagement pressure builds up slowly, reducing the shift shock when there is a shift from first to second gear.