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What exactly does the kick down lever do???

Red63440

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I noticed that my kick down linkage has been welded where it screws on the shaft and then to top it off there is a bolt about half way up the slot.....WTF....they screwed with just about everything on this car and it will take me months just to find everything.
 
Ok, I was wrong, it hasn't been welded but it does have a small bolt about 1/2 way in the slot. How would the car be affected by that bolt???
 
OK, let me quess......higher than normal rpms once the bolt makes contact with the carb stud. It would make gears seem deeper than they are due to using the transmission passing gear as a multiplier...am I close????
 
It would make it shift at higher RPM's and likely restrict full throttle. Sounds pretty goofy to me.
 
Sounds totally f*&%ed up to me.......wonder if thats why the 3.91's felt like 4.56's????
 
Now I understand why you said "multiplier". I didn't realize you were driving this. This is some kind of redneck shift kit or some cover-up for some transmission problem. I'd say the only thing to do is put it back to stock linkage with proper adjustment and see how it drives. Then decide what to do next, start somewhere that you know.
 
The car is out of Texas but the transmission is fresh and has a shift kit and new converter. I am thinking that the bolt was installed some time ago and over looked by the previous owner. Yep, it has been removed and pitched but I still want to know what the purpose is for the linkage is and how to adjust it correctly.
 
The factory service manual would be a big help on this, it is pretty clear on how to adjust the kickdown, at least my '68 manual is. If it would help I could scan that section and send it to you.
 
I've seen the nut and bolt trick before- a guy had a mix match of big block and small block linkage on a car and couldn't get it adjusted right without a bolt in there- if you're not sure all the parts are right I have a complete set of each. You're an hour or so away, you're welcome to stop by and compare your parts to mine and see if you have the right parts on there.
 
kickdown lever

the lever on trans. should be all the way back ( or close to it ) at full throttle. it supplies more pressure in trans. if not your trans. can begin to slip. sounds like you have the wrong linkage and the bolt in the slot was supposed to make it work. it's easy to see how it works. try this,(car not running) hold throttle all the way open, now with other hand push k.d. linkage all the way back. you probably have a lot of free play between carb stud & slot. thats why they used the bolt.
 
The linkage is BB so its not mis-matched parts, I will see how much slot I have left working it by hand and go from there. Thanks for the input guys.

Bill, if you can scan that page and email it to me that would be great.
[email protected]
 
Removed the 1/4" nut and bolt and adjusted the linkage so when the throttle is in the WO position there is about an inch of travel in the kick-down rod. Not sure how much I should have but hope to find out.
Another mystery solved....NEXT!!!!
 
Does the kickdown lever move at exactly the same time the throttle moves? If not, you need to fix it so that it does and if you still have another 1/2" of travel at WOT, sounds like you have too much. Get the adjustment info for your car and adjust it according to that unless the car is modified with an aftermarket intake etc. The book will still help you adjust it but you may have to modify the linkage to work right. I modified a small block setup when I installed a big block in my car and welded a washer in the slot to make it work right....but that was many moons ago.
 
In the very, very near future the addition of an intake, cam, 915 heads, larger carb, headers and a few other items will be made. The way it sits right now the throttle will move about 3/8" before the kick down starts to move, I have no adjustment left and would have to modify the existing linkage to have immediate movement. I have no idea as to how the additions will affect the operation or mounting of the linkage, only time will tell.
 
The kickdown linkage increases the line pressure and "forces" the clutches together in the transmission. (to greatly simplify it).

A non-working or poorly working kickdown WILL allow the clutches to slip and WILL burn up your transmission.

As others have said, make sure it moves the lever all the way back on the transmission when the throttle is wide open.

I decided I was tired of a kickdown and all the hassles associated with it and bought a Turbo-Action Pro-Street forward pattern manual valvebody! Well, that was one of the reasons anyway....
 
I guess on Monday I will take the end to work with me and weld in a 1/2" filler in the slot, that should give me all I need.
 
Here are a few photos of my linkage....please excuse the crappy looking engine, valve covers are being bead blasted prior to the rebuild. I have no other linkage to compare what I have with.
 

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kickdown linkage

if that slotted end is'nt threaded onto the rod (for adjustment) , might be a good idea to go back to the "bolt trick" until the new setup is in place, then modify linkage- might be alot closer to being "right" with new stuff. as cranky said, it shouldbegin to move when throttle moves & all the way back at wot. almost a 1-1 ratio
 
With that setup, it looks like the throttle will move a good half inch or so before the kickdown rod moves and that's not right. It's also supposed to have a return spring on it too....
 
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