TH400 detent question

Discussion in 'The "Juice Box"' started by hjsonnie, Jun 30, 2020.

  1. hjsonnie

    hjsonnie '51 Henry J '72 Skylark

    I recently acquired a long missing detent switch for my Skylark (455/th400 setup).
    I installed it and notice that at WOT the pedal rod just touiches the switch, not actually engaging it.
    So, the question is were should the pedal rod be in reference to the switch lever when unpressed?
     
  2. BQUICK

    BQUICK Well-Known Member

    I've always had to put a piece of 3/8 fuel hose on rod to get it to actuate. One car I put a chore acorn wheel nut on it to engage.
    I think things get bent/tweaked over years of mashing pedal.

    Also: the plastic slider on the switch needs to be reset (press tab and push) then it self-adjusts to some degree but still usually not enough.
     
  3. hjsonnie

    hjsonnie '51 Henry J '72 Skylark

    Sounds like something to try first. I thought maybe I had the wrong pedal assembly. But I have the old TH350 pedal and it's different.
    It would be nice to have an actual kick down on hard acceleration. Cable length and travel all check out good though, too.
     
  4. BYoung

    BYoung Stage me

    Need to reset your switch by pushing it towards the firewall.
     
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    DetentSwitchAdj.jpg

    You can bend the actuating part of the gas pedal rod, or put some fuel line hose on it. That's what I do at the track when I swap to my Holley 1000 DP carb. The throttle throw is shorter, and that is the only way to get it to engage the gas pedal switch. If I forget to (which I have been known to do:))put the fuel hose on there, the trans short shifts.
     
  6. hjsonnie

    hjsonnie '51 Henry J '72 Skylark

    I guess I could see how much idle setting adjustment there is at the carb. To see if I could bend the pedal rod at all without idling at 1500 rpm. I have full travel with the pedal as it is and almost at the floor when fully pressed and carb at WOT.
     
  7. hjsonnie

    hjsonnie '51 Henry J '72 Skylark

    Well, I got a little time to play. I got the pedal rod to activate the switch and feed electricity to the tranny lead. However no power at the tranny plug. Looks like time to chase fifty year old wiring mystery. Thanks for all the help.
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    You can always run your own wire to the transmission.
     
  9. hjsonnie

    hjsonnie '51 Henry J '72 Skylark

    Very true. I had to splice in a new tranny plug a few years back during an engine rebuild, so I want to check it out first. Thanks again, Larry
    We met years ago at Ken Lisk house in CT. He was having cruise in and I came by to pick up his old x- pipe exhaust. Have a good weedkend!
     
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I vaguely remember that. One of Ken's prior residences, he lives somewhere else now.
     

Share This Page