Drive Range-Overdrive
In this range, the converter, 4th, direct and forward clutches are applied and the transmission is in Drive (D) range-overdrive.The converter clutch may or may not be applied, depending on solenoid operation.
As both vehicle speed and governor pressure increase, the force of governor oil acting on the 3-4 shift valve overcomes the force of the 3-4 T.V. spring and M.T.V. up oil and permits the 3-4 shift valve to open, resulting in RND4 oil entering the 4th clutch passage. Fourth oil then lows from the 3-4 shift valve to the 4th clutch piston, which applies the 4th clutch. At the same time, 4th clutch oil moves the 3-4 accumulator piston against accumulator pressure and the accumulator spring to maintain a controlled build-up of pressure on the 4th clutch during the 3-4 shift This results in a smooth, easy shift