Fluid Pressure Directed in Preparation for a Shift to Fifth Gear

345 fluid is routed through the 3-4 shift valve (345) into the 45 fluid circuit.

45 fluid seats the #3 ball check valve and passes through orifice #27. This orifice helps to control overdrive clutch apply in fifth gear.

45 fluid is routed to the 4-5 shift valve (374) where it is blocked by the valve in preparation for an upshift to fifth gear.