No kickdown on Pontiac Th400

TH400s have an electrical kickdown, not a mechanical linkage. Google "TH400 kickdown switch" for part sources. On models that came with the TH400 back then, there was an electrical switch that was mounted at carb on throttle linkage, when the linkage was at WOT (wide open throttle), it connected and supplied 12V to a solenoid in the tranny that did two things, increased line pressure to prevent damage to clutch and downshift tranny (depending on gear). Lots of TH400 retrofits involve installing that switch as well. Don't run tranny without it, as again you can damage clutch due to lack of increased line pressure.

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