Could someone explain whether my '64 F85 Jetaway trans has a passing gear?
We have the switch pitch in operation, with hi-stall or low stall setting quite noticeable.
But both settings result in same engine rpm at 30 mph in low gear (2500 rpm). We installed a toggle switch and see no difference in rpm.
'64 F85
330 2bbl
35,916 miles
4 door though

A little more background: The super turbine 300 wiki page mentions a 1.8 and 2.45 ratios (both in low gear) based on hi-stall vs. low stall. So we're confused.
Link: http://en.wikipedia.org/wiki/Super_Turbine_300

 

The passing gear is @ wide open throttle. It sends 12v to the trans terminal next to the switch pitch terminal at the connector on the trans. The switch is either on the throttle linkage, carb, or gas pedal.

 

Let's back up. First, "passing gear" is simply a euphemism for "downshift". Any automatic trans is supposed to automatically downshift when you floor the throttle for added acceleration. The two hard gear ratios in the Jetaway are 1.76:1 first and 1:1 second.

Now, here's were it gets a little complicated. The Jetaway has a switch pitch torque converter. The stator vanes inside the torque converter aren't really static. A hydraulic actuator actually moves the vanes to one of two pitch angles, which changes the stall speed of the converter. Under normal driving conditions, the converter has a low stall speed like a normal AT. When a solenoid valve actuates the stator, the vanes move and you have a higher stall speed converter. What this does is increase the torque multiplication in the converter, giving you a higher effective gear ratio, which is that "2.45" ratio you read about. Keep in mind that this is not a hard gear ratio but a theoretical ratio based on the additional torque multiplication, and the effective ratio actually changes with load and engine RPM.

On your car, there are two sets of contacts in the kickdown switch in the accelerator linkage. One set is connected to the normal downshift solenoid and should only make contact at wide open throttle. The other set is connected to the switch pitch solenoid and should make contact at part throttle and again at W.O.T. This way you get the added torque multiplication at part throttle for midrange passing, and also at W.O.T. for maximum acceleration.