I put a newer TH400 (non-switch-pitch, and non-timing-control) in my 67 ragtop. (only one electrical spade on the side) I'd like to hook up something to that kickdown plug on the tranny.... My throttle linkage has a switch on it already (original 67 throttle lever for a 300 2 barrel with 2 spd powerglide) I assume that switch won't work for the TH400? Or maybe it will? Can I buy one of Mike G's switch kits? Will it fit on my pedal? When should I see 12V at the tranny? WOT? Part Throttle? If it's only supposed to be a WOT switch (which I think it might be), why do I remember some cars kicking down at half throttle? Does the vacuum modulator have a role in this too? Jeeze, that's a lot of questions.... maybe I better stop for now. :laugh: Thanks :beer
I was just playing with the existing switch on my throttle linkage.... I can't see how it would ever toggle? I can toggle it with my fingers, but it never gets toggled regardless of where I move the throttle linkage. Maybe I'm missing some parts or something?
+12V goes to trans up full pedal motion. You can run a wire from the "ign" terminal to the switch and then to the trans. I think 68-72 brkt will work on your 67
The throttle switch or gas pedal switch simply passes 12 volts down to the transmission. This happens well before wide open throttle, but depending on transmission calibration and other factors, the downshift may or may not occur. This article deals with switch pitch transmissions, but the valvebody calibrations discussed also apply to fixed pitch transmissions. Since your trans is a 71, you'll have a part throttle kickdown under the right conditions. http://www.buickperformance.com/SPTrans.htm I'm assuming you meant ST300 instead of powerglide. The 400 and 300 transmissions both use an electrical kickdown, 12 volts is 12 volts, so your original throttle switch should do the job if it is functional(test it with an ohmeter)
Rick, don't know if this will help or not, but here's the original setup for the '67 ST300 switch: http://home.comcast.net/~shinzan/ST300_linkage.jpg Devon