1967 TH400 Switch Pitch
#1
1967 TH400 Switch Pitch
My first post. Upon light throttle application the trans shifts rapidly into 2nd (5mph), then into 3rd (10-15mph). At wot 2nd (15mph), 3rd (40mph). Acceleration is very weak. Selecting 1st, then manually shifting @4400rpm through the gears, the acceleration is tremendously better. The vacuum from the intake manifold is connected to the trans on the passenger side fwd (some sort of little servo can device). The firewall throttle kickdown switch is round and about 3" in diameter. It has three prongs. One has a orange wire that is 12v from an ign "on" fused source. The other two prongs, which are 90 degrees to each other, and have a connector that goes down to the trans. Have power on one wire that goes away when the throttle is between 10% to 20% opened, then gets power back on it . The other prong doesn't read anything. I think it should. With that said, where does one get a new/used throttle kickdown switch? Or tell if and when the swtch should activate for each prong. Do they activate at different throttle settings? Thanks to all, in advance, for help with this problem.
George Landis
George Landis
#2
The prong you have power on it at 10 to 20% opening is the switch pitch control, where the other prong with no power should have power at wide open throttle, this being the kickdown control. If no power at WOT then replace the switch. As far as the early shifts, this could be vacuum modulator or the vacuum source for it. Check the vacuum at the trans with vacuum gauge at idle. If the modulator and vacuum check good, then governor may be bad.
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