Kickdown issue?

[428Marauder]

67 428 with a C6. Makes my big, heavy car go fast without the need to floor it. However, I have tried to open it up a time or 2, just foot to the floor, see what it does ... and this is how I would describe it:

You feel the trans shift, and the engine revs ... but there is almost a speed decrease. It almost seems like what would happen if it was a manual trans and you shifted into neutral and floored it.

Someone said I needed my "kickdown adjusted". Any tips?

[428Marauder]

There seems to be an exception. I haven't fully tested this yet, but, with the tree selector I have D1 and D2. D1 is all low torque stuff ... D2 is full trans shiftability (where I have this problem) and since my shifter is old and worn out, sometimes I am accidently in D1 ... and I know I can shift, manually into D2 on the fly, but it seems much faster and more responsive to the throttle, but then I need to shift it to D2 or it tops out.

What I haven't tried is flooring it in D1, just to see what it will do off the line, my guess is sputter and stall. I think there is also an L ... which I guess is for towing or, pulling stumps, or something.

[ScotiaFE]

Couple of issues here.
Your 65 never came with a C6 so you would have had to make up a kick down system.
I'm guessing you did not make one. So the trans is not down shifting as you expect.
If you have slop in the shifter that won't help you.

[ScotiaFE]

A picture of a 67 Fairlane column shift C6 Kick down linkage.

 

[428Marauder]

The engine and trans came out of another car, but I think you are right. I have no linkage. So, I need linkage?

I should probably mention that I don't fully understand what "kick down" is. I just want it to go fast when I floor it.

[Heo]

I dont know with a C6.
But on many autos without kickdown linkage
instaled and adjusted  you burn up the trans
internals

[ScotiaFE]

A bit of the kick down workings.
When you stab the gas pedal it will send a signal to the modulator valve.
This is in conjunction with the down shift lever "kick down lever" to force  3 to 2 down shift.
Fluid moves around in the valve body.
The speed at which this can occur is controlled by the governor.
There are tons of diagrams available on the C6 to see exactly how this works.

I would recommend you figure out a way to make the system work.
It will make you trans work better and last longer, but you will also enjoy the ride even more.
The C6 is an excellent trans and pretty easy to get working good.
Good luck with your very Kool vert.

[428Marauder]

So, I need to find some linkage on ebay or something? Is it easy to install?

[428Marauder]

What about these kickdown cable kits on ebay? Anyone have any experience there?

[runthatjunk]

You sure you don't have a linkage?  If you floor it and it drops to second and revs up then it sounds like it has a linkage, but may be shifting too late, or your engine just doesn't want to rev as high as needed to increase the speed (or your tranny is shot and slipping like crazy).  Also sounds like you shifter pattern is D,2,1 rather than d1,d2,L  because d1 or d2 will both shift into high gear.  As far as a linkage I'm sure they are readily available last one I needed I took some steel fuel line bent it to shape hammered the ends flat and drilled holes in the ends for the tranny and carb.

[428Marauder]

Yes, I do have linkage, it turns out. I took the car to a tranny shop once, and they wanted rediculous money just to drop the tranny and inspect it. Could be though, it needs rebuilt.

[ScotiaFE]

Good news about the linkage.
Probably the worst thing about rebuilding a Auto trans is the mess.
I got plastic drum and cut it in half. When not in use it stores out in the junk pile and does not rust. 

The C6 is not a tough rebuild and can be tackled in the shed no problem.
For huge cost savings.

[mammyjammer]

I did my own C-6 with a Badshoe video, a factory shop manual and Broader 500 HP rebuild kit. So far so good!!