do i need a kickdown cable for a 400th trans? i know that for a 350th if you disconnect it i would have to manualy downshift when going up a hill or passing etc. I assume its the same for the 400th but i figured i would check. Thanks for any help

-Bailey

 

I am no transmission guy but I think the 400s have a solenoid and a switch was on the gas pedal for the kick down

 

The TH400 doesn't use a kickdown cable at all. It uses an electrical detent (downshift) plunger switch that is operated by your carb's throttle linkage. You could hotwire a "momentary" switch instead of hooking it up to the linkage if you needed to, or put a momentary plunger switch inside the car that will get pushed in when the gas pedal goes to the floor.

 

Ah ya beat me to it. I had just remembered there was a plunger switch on the carb and was going to suggest some thing like a Nitros switch. But there were some that also had a switch that operated off the gas pedal as well.

 

if you got enough gear and power you really dont need it

 

Not allowing the trans to downshift lugs the engine, which keeps your engine's RPM's below the optimum power band, it hinders performance, and also builds up more heat in the trans. Other than that, yeah you don't need to downshift. You could always just shift manually.

 

I have a friend that thought he got more passing power if he dropped his foord van into first to pass (on the freeway). I told him there is a reason there is a kick down and he was over reving his engine past the max HP and he was gonna F@*# it up. Well what the hell do I know. He continued to do it and proved me wrong. He did not screw up his engine. He blew up his tranny!

 

I have a well built T350 in my '69, with a manual valve body. So whatever gear I put it in is where it stays. If it's in third at a stop, it starts out in third. And even though the engine has plenty of grunt to move the car in third, it's bad for the trans. You obviously need to know what to watch for (the tach) as well as keep a tuned ear when shifting manually....gee, kinda like when shifting a manual trans! As in your friend's case, common sense is key. Unfortunately, common sense isn't always so common.

 

my 400 turbo shifts automatically and even shifts back and forth from 3rd to 2nd when at slow speeds without the kickdown hooked up.i had a bb truck with a 400 in it.i had the kickdown hooked up and below 45mph it would not kickdown.

 

Bowtieguy, you're describing the normal shifting cycles which is controlled by the governor. I don't think my earlier point came across quite like how it sounded in my head. I may have made it sound like the kickdown controls the normal shifting, which it doesn't. It's just better to have the trans kickdown to a lower gear when the foot goes down. But as you found out, sometimes the trans has a mind of it's own, which is why I still like to shift it manually and put it where I want, when I want (within reason of course).