What did you guys do for the electronic kickdown?

I used to have a slider switch on a homemade bracket with a linkage off the carb but it never worked that great... right now i have a small thumb switch on the shifter for a quick downshift, but it kinda sucks... lol

Does anyone make a kit or anyone got any ideas on how to make this work better?


Thanks,
Dave

 

the th 400 i have dont have any electronics on it , its all manual . i know they come with a kick down cable . thats it .

 

hmm, all 4 of the ones i've had all had the solenoid kick down... no cable.

 

A 'real' th400 should be all manual (vac modulator/kickdown cable)


The 'new' th400 is called the 4l80 and is basically the same.

But a 4l80E is what your talking about, the 'E' obviously stands for electronic.

Either a modded computer from a newer car or an aftermarket computer can be used to control it.

 

Both TH400's I have, have a single spade connection for the kick down. One was an older model TH400 and I'm not sure about the one in the car now. Lokar makes a kickdown with the cable activated switch. Do I run one? No. I just manualy drop it down if need be.

 

you can just manually drop it down or run a lokar type kickdown setup or a switch, but i find just pulling down on the megashifter easier than flipping switches.

 

all 4 of my TH400's came from late 70's trucks

vacuum modulated but no kickdown cable...

in this pic you can see the vacuum modulator and the kickdown solenoid. The solenoid isn't mounted but it would normally bolt up and to the right on the upper valvebody.



that's a 1979 tranny from a chevy truck


xpndbl3 and EvilCartman, that's what i've been doing. Thanks for the replies!

 

The 400 has had an electric (NOT "electronic") kickdown since it was introduced in 1965.

No cables on a 400; not kickdown, not TV or modulator. Ever. Always electric.

Most cars had the switch located on the gas pedal. Cars I've had that were made that way, included 66 Caprice, 69 Chevelle, 74 Caprice. I've seen a few other vehicles with it mounted on a bracket behind the carb; I can't recall what they were, whether they were trucks, or some car other than Chevy (BOP), or what. Seems like putting it in the interior would be easier anyway.

Holley used to sell a "universal" backup light switch kit, that you bolted onto your shifter, to light the backup lights. The reverse arm just sort of bumped into it when you put the car in reverse. That would be the perfect thing to make what you need out of. All you'd have to do is mount it to the gas pedal bracket, run switched ignition to one lead of it, and run the other lead to the solenoid terminal on the transmission.

 

Could you please tell me why theirs a modulator on there then?

Modulators there but i guess the kickdown is operated by solenoid on the th400s...

 

Yep, Modulator is there. It shifts like crap with it unhooked too... my LT's have melted a few vac lines now.. lol


The "slider" switch i have actually came from an old chevy delivery van, it was on a bracket and hooked to the gas pedal. Maybe i'll try to fab something up to work with mine like that...

 

The modulator is VACUUM, not a CABLE.

 

Are you using a big length of vacuum line? If you are, just get some metal tubing and use some vacuum line on the ends for the connections.

 

Summit has two kits: BMM-20297 & HUU-2488605. I still have the original '66 system for the '57, although I haven't had the switch hooked up for a couple of years.

 

See, i knew i joined this forum for a reason. Thanks for the good idea!

 

On my Th350C ive got a small chunk of rubber hose coming off the modulator then steel tube up to the manifold where it once again goes to rubber line and to the vac port.

I imagine i would have a similar problem like you if i didnt have the metal tube, those long tubes can get really freakin hot!