kickdown rod dilemma - throttle not opening fully SOLVED !!!

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Finally got some time before work to check out my linkage. There is no binding when adjusted either for wide open throttle or for full motion on throttle pressure linkage.

I pulled the pan and everything looks good there. There is a little bit of gunk in the pan, but this is the first time having it off since rebuilding the transmission and running 700 miles.

Specs for throttle pressure and line pressure adjustment are good. Here are some pictures.

I'm still thinking it's a fulcrum issue where throttle pressure lever takes a lot less motion than the throttle shaft. I was hoping to stay away from a Lokar cable. Maybe I can can fab up a bracket like Trailbeast. Just have to make my wife's skillet disappear!!

First picture is throttle pressure pin at rest, second is throttle pressure full movement.

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Maybe a difference in height from where bracket mounts on the different heads? Pics of where rods mount at each ends? Maybe someone will pick up on something?
I agree with no Lokar...just a preference thing, but gotta be something simple?:BangHead:
 
I read a very simplified explanation of those "fulcrum points", etc... someplace. If I understood correctly, the length of the levers on the carburetor and on the kickdown lever on the transmission need to be identical on Mopars. Distance from the shaft it is turning to where the rod attaches must be equal on both levers. There are a bunch of different transmission levers available.
 
I always try the easiest thing first; like in Post #24. Now you have to put the pan back on to test drive any changes. Can't you just move the kd point down on the carb lever like I suggested? Or is the hole too small?
 
CudaFactHackJob said:
I always try the easiest thing first; like in Post #24. Now you have to put the pan back on to test drive any changes. Can't you just move the kd point down on the carb lever like I suggested? Or is the hole too small?
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I'm enjoying my lunch break at work and checked in. Thanks for your replies.

Anywhere I mounted (held in place temporarily) the rod on the carb adapter, it was too much travel. In other words, the throttle pressure lever on the transmission reaches maximum movement way before the carburetor throttle. Anywhere on the adapter was either hardly any movement or way too much. I figured I could drill a hole if I can find the right spot.

I dropped the pan to ensure everything was moving as it should. Also wanted to see what the pan looked like after my transmission rebuild.
 
69_340_GTS said:
I read a very simplified explanation of those "fulcrum points", etc... someplace. If I understood correctly, the length of the levers on the carburetor and on the kickdown lever on the transmission need to be identical on Mopars. Distance from the shaft it is turning to where the rod attaches must be equal on both levers. There are a bunch of different transmission levers available.
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I'll check out the lengths. It will be interesting to see.

I had a 273 4bbl in there for many years but never noticed if I was getting full throttle travel or not.
 
Sometimes I repeat myself if I think nobody is listening nobody is listening. Both radii being the same might be true, however, that would be assuming that each arm is centered at 90 degrees at mid arc..Have I seen some linkages that change ratios at the bellcrank?
 
I think we're listening, we just need to work through the suggestions and advice.

I wanted to close the loop in case anyone comes across this thread later.

So...after a thorough visual inspection, I found the kick down (throttle pressure) linkage was hitting a ball stud that was in the hole beneath the mount for the throttle and existing kickdown linkage (1st picture). That's what kept the throttle from opening all the way.

I just cut the ball socket off and moved the kickdown linkage to the lower ball stud (picture 2). After lots of test drives and kickdown linkage adjustments...its perfect!!! Good, crisp shifts from my rebuild and I love the part throttle kickdown of the 74 transmission while driving n the hills.

I'm pretty sure @CudaFactHackJob suggested that hole earlier in the thread, Thank you for that!! I just couldn't see it helping at the time... or I'm hard-headed :BangHead:

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Should u not have the kd hooked up to where ur throttle cable hooks too. U would just have to change the stud and the kd end. Kim
 
oldkimmer said:
Should u not have the kd hooked up to where ur throttle cable hooks too. U would just have to change the stud and the kd end. Kim
Click to expand...

Thats how I had it at first, but the kickdown bottomed out and kept the throttle from opening more than about 60%.

With the kickdown in the lower position, the throttle opens all the way at the same time the kickdown reaches maximum. It took a lot of back and forth adjusting both, the rod at the carb and the rod going down to the bellcrank, but I'm happy with the result.
 
66fyssh said:
As soon as I go back to a longer rod and take all the slack out of the throttle linkage, it shifts great.
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I just finished up this build. I put a Demon 625 double pumper I had from another build (gm). The trouble was the throttle linkage on the carb pulled AWAY from the trans kickdown. This car at some point in the past had a slant six with column shift that had modified intake brackets to adapt existing linkage to the V8. The rest is one looong kickdown rod to the kickdown lever on the trans. We made up a new " flat blade slotted bracket " to attach to the TOP of the carb linkage travel to PUSH the kickdown rod to activate the kickdown. In the garage with engine off with the gas pedal mashed, my helper observed the kickdown rod pushing the trans lever all the way back ( but not into a bind ). Yet with Pro complete rebuild with shift kit and stall (2500) with 3:91's I too am not achiving a " kick down " on the street. I am investigating this later today. There is a youtuber 318willrun that had some good footage about this.
 
Sounds like you're making a lot of progress. Its boring when everything falls into place too easily, lol.

Hot Rodding!!
 
The custom made bracket to attach to the other guys custom made bracket - six popper cable to V8 thumper swap. Factory made it a bit to complex to begin with & that leaves us hot rodders to improvise a safe but effective solution short of ordering from Lokar....will be adjusting and street testing today. Again this is a 360 with a 727.

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