Turbo 400

[chris718]

oil is sent to a land on the modulator valve that pushes the valve in the direction of the vaccuum supply lowering line pressure.exhausting this oil by grinding a land on the modulator valve stops this biasing but causes a loss of 3/2 modulated kickdowns from the 3/2 valve.plugging the hole in the plate is more effective but lightening the secondary weights brings back the part throttle modulated kick down

 

[Gregaust]

Thanks Chris ..

 

[chris718]

The hydraulic circuitry on the manual shift th400 with brake is no where near as complex as the automatic shift 400.Get the hydraulic diagrams and take a look.Circuits are very well designed.4O plus years later its still a killer piece.Then its overdrive version arrived.The 4l80e.Another true work of mechanical genius.We are selling more 4l80es right now than anything else.