So the only problem with my supersix conversion so far, is the trans is not kicking down when I floor it.
When I installed the kickdown linkage I adjusted so the linkage would be as long as possible (maximum travel) and its still not working.

Anyone else had the problem after supersixing ? Do I need to lengthen the linkage some how to allow for more travel ?
How has anyone else solved this problem.

Thanks
Scott

p.s. trans was working fine before conversion

If the throttle pressure lever (down on the trans) was moved too far forward without a linkage rod installed, it's possible that it's no longer correctly pressing on the throttle pressure valve in the valve body. If that's what's going on, then no amount of linkage adjustment will make the trans respond (your ordinary upshifts will also probably be very short/early).

But before you drop the trans pan, make sure that the 2bbl linkage is installed correctly all the way from the top to the bottom -- a common error is to get the "U"-shaped pivot link upside down so the trans pushrod is below the fixed bracket rather than above it, for instance.

I've also seen guys bend the link rod to clear special exhausts, etc., figuring "just a little bend couldn't hurt", not realizing they were shortening the link so much that it couldn't do its job.

I seem to remember when I did my first conversion 100 years ago, I used the original lever on the trans and had similar problems. The super six lever was different, if I remember correctly, it was either longer or at a different angle when at rest, or both. Make sure you're using all the super six linkage from the donor car.

D/W

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If it ain't broke, fix it!

YEP, good catch, the 2bbl trans lever is different, actually believe it is shorter than the 1bbl lever, and you must use the correct lever for the linkage system.

You're right... It was shorter. Been a while since I "super sixed" anything.

D/W

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If it ain't broke, fix it!

OK, I was just reading in the "article" section, in the supersix article and you guys are correct. it says there are different levers for the transmissions.
Unfortunately I didnt get the transmission lever with my supersix linkage. But that might explain the problem.
If I knew how long it was suppose to be, I could probably modify the one I have.

my super six kickdown wasnt long enough to push the lever on the trans all the way back, i guess because of the lever length yall are talking about. i used the 1 bbl kick down rod and it worked great. easier to adjust too.

Just measured some kickdown levers. The super six lever is 2 1/2 inches from the pivot to the rod hole. Also had some other levers that are 1 1/2 inches and 2 inches. These are on core transmissions, and do not know what the carb setups were. I cannot tell how the angles compare.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Or maybe I was right the first time! I wonder if I should stop second guessing myself or not...

D/W

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If it ain't broke, fix it!

I had the same problem, and I am using the correct SS linkage. It took a while but I took it apart and straightend out the bend in the rod slightly, then I just had enough to make it work.

In my case the rod had likely bent from how they stack the cars one on top of the other in the junkyard. Now that I think of it I had a bitch of a time getting that pin undone to free up the linkage when I was pulling it.
Todd

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72 Scamp 225 /6, auto, radio delete, alum super six, cold air duct, pertronix ignitor II and flame thrower, 3.23 rear, 2.25" free flow exhaust

Well well well, learn something new here every day. I've wondered about the lever length on the trannys. I have a tranny from a 2bbl s6 burried deeeeep in the shed. Gonna take me a couple hours to dig it out to measure it up.

FYI.... any of you guys and gals who might be swapping stuff on slant 6 trucks to cars or vise versa...... I noticed the bell crank below the 1-bbl carburetor (mounted to manifold) on my 1987 S6 truck is a much different proportion or ratio than the one on my '76 Valiant.

Both of mine have custom made kickdown rods.

The truck had shift link clearance issues with the rod from a car, so I purchased some rod stock from the local hardware store and bent to fit. On the top side, I weld a short piece of square tube stock and drill a hole.

My car is a more complex fab, with a one of a kind handmade bracket and rod. It helps that I had correct pieces around to compare to, but still took a good chunk of time to make it all work smooth.

Maybe I'm just fab happy. $70 seemed like a lot of money for a kickdown till I spent an entire day making a reproduction.

Haven't published this work in a while and I know that the angles on the kickdown rod (in the pdf) have been reworked to fit my car. Maybe it will help somebody someday.
http://www.potentialtech.com/pmoran/bracket2.pdf
Here is a preview. Sorry for the big download size. Otherwise text wasn't clear.


I'll have to take some pics of the working item when it stops raining.

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1980 Aspen 225 super six

You're as bad as me! I freehand whittled some stuff for my Duster AFB from a chunk of Aluminum (well actually I made it for the aborted 390 Holley, then had to whittle another offset to run the AFB - see pics in slixer's section for reference). The rate wasn't right, so then I had to reinvent the connection at the trans lever by adding a stiff spring, a slider and two stops. The trans lever actually hits it's stop before the carb gets to WOT, then the rod just compresses the spring. This actually works quite well for shift points and firmness with the 4-barrel. kickdown is early, but that's fine with all that carburetion, you don't need WOT to pass!The point is, why didn't we just spend the $$$ and get the cable? Well, I don't think there was one available when I was doing all that engineering, would I do it again? Hell no! But Slant6Ram, I hear what you are saying, it can be satisfying to make stuff work yourself.

D/W

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If it ain't broke, fix it!

Slant6Ram, that's a NICE piece(s) of work you did there!