Lets talk Kick-Down Setup

[Moparfiend]

OK just a few details on my SB kick down set up.

It seems to me that for the setup to work correctly both the carburetor throttle throw or travel from idle to WOT needs to equal the kick down travel.

If the throttle travel is longer than the kick down linkage the throttle will not make it to wide open as it would be jammed up with the KD linkage.

If the throttle travel is shorter than the KD linkage then you wont get full pressure on the trans.

It seems EVEN IF the intermediate rod is set up correctly with the so called special tool the travel of both the carb and KD needs to be the same but not set by this adjustment.

So what am I not understanding about this geometry and its proper adjustment?

 

[Photon440]

Hope this helps, it's from the 1970 FSM.

 

[Moparfiend]

This video is much beter albeit very dry and corny.


My question however still stands....

 

[Moparfiend]

Chrysler Video indicates: What were shooting for is minimum transmission pressure at curb idle and as soon as you crack the throttle you engage the transmission pump to start increasing pressure. Then finally at WOT the transmission pressure is at its maximum.

This is precisely the dilemma I am referring too. The throttle and transmission pressure should start and move together UNTIL you reach BOTH WOT AND Max Transmission Pressure i.e same throw length!

 

[66 Sat]

I think you're nearly there on your thinking. The kickdown lever does start to move as you open the throttle, and by full throttle is at maximum movement. The various adjustments are made to allow this. When you open the throttle by hand you can feel the lever and bell cranks moving and the slight "springiness" as the final lever moves underneath on the transmission itself. What is the dilemma you have?

 

[BeepBeepRR]

 

[Ron H]

Jumping in the post to hear more on this as might be I've missed something with my set up. I may be over simplifying what I had done. My gist was the KD rod adjustment assuring near full travel with the VB trans lever at WOT...

 

[hanks73340]

After reading so much on this subject I'm gonna invest in the Lokar Cable kit. Tired of playing around.......

 

[Moparfiend]

I think you're nearly there on your thinking. The kickdown lever does start to move as you open the throttle, and by full throttle is at maximum movement. The various adjustments are made to allow this. When you open the throttle by hand you can feel the lever and bell cranks moving and the slight "springiness" as the final lever moves underneath on the transmission itself. What is the dilemma you have?

My assumption that the KD throw must be equal to the throttle throw in a properly adjusted set up. However the instructions do not clearly state this and infact have you set up the intermediate rod independently from the top throttle assembly. So the throw of the KD can only be adjusted by the top linkage. Thats not enough to adjust the throw and infact should only be adjusted to provide max transmission pressure at WOT of the carburetor position.

There must be something I am missing here as I have read the factory assembly manual and watched the factory videos as well as other but never any mention of this geometry adjustment or question.

 

[oldbee]

I guess easy way to look at it is that factory figured out correct lengths of all the rods to get what they wanted. Now, if you go from 383 to 440,318 to 340, different intake/ carb,etc. something has to be added/subtracted to one of the rods to get back where you need to be. I had to add a short extension to intermediate rod to go to a 440 for example.( different engine height)

 

[Don selleck]

After reading so much on this subject I'm gonna invest in the Lokar Cable kit. Tired of playing around.......

I'm about to install that set up here shortly. Good to know that the kick down works evenly with the throttle position. Glad I read this thread.

 

[BeepBeepRR]

You have an adjustment at the rear of the engine in the rod that goes down. That adjustment will give you more throw forward and backwards on the pump lever on the transmission. The trick is to get the proper throw to shove the transmission lever all the way back at WOT. Watch the first video above. Its is very helpful to show how it should be set up. I mean these setups have worked for years as they were engineered to. With proper setup they will last for years to come.

 

[Moparfiend]

I guess easy way to look at it is that factory figured out correct lengths of all the rods to get what they wanted. Now, if you go from 383 to 440,318 to 340, different intake/ carb,etc. something has to be added/subtracted to one of the rods to get back where you need to be. I had to add a short extension to intermediate rod to go to a 440 for example.( different engine height)

Hum I hear ya but this implies that there is essentially no adjustment for the Kick Doen throw and that it is preset by the original geometry and rod lengths of the intended design. I think my set up is ver close to doing exactly what I need from this mornings effort in adjustment. Will follow up with a post of my final set up if I can get it to work. I am using a small extension and this would support your claim here!

 

[AR67GTX]

Good - but confusing subject. I agree that if I hold my throttle closed and adjust the KD rod per the manual with the index pin in the bellcrank and all - I get a bit different setting than if I hold the throttle wide open and adjust the KD rod to just short of full travel.

There seem to be two theories of correct adjustment - one with throttle held closed and one with throttle held wide open.

 

[BeepBeepRR]

The correct way is to make sure the back side of the slot is resting on the throttle pin. Then go under the car and make sure that the pump pressure adjuster is all the way forward. Then Go to WOT on the carb and check the lever on the trans. If it is not all the way back for max pressure then I would suggest adjusting the rod that goes down behind the block. That rod will give you more front to rear throw on the pump pressure lever. In the second video they go over several styles of kick down linkages. The tool they use to set this up pulls the pump lever all the way forward. This is how you set the rod with the slot in it.

 

[Moparfiend]

A yone gave a y drawings of the adjustment tool? It would be a simple thing to make.

 

[Dipstick]

OK just a few details on my SB kick down set up.

It seems to me that for the setup to work correctly both the carburetor throttle throw or travel from idle to WOT needs to equal the kick down travel.

That's all you need to know and, if it isn't a factory carb, you need the correct throttle lever adapter to make it happen.

 

[oldbee]

And then there’s ‘beepbeep’ throwing a little wrench in the thread,lol. We’re all right, but after 40+ yrs there’s different ways to get there.( wear on threads,ball sockets,throttle plate rotation)

 

[miller]

How about another iron in the fire.

First 'sticky' post, all about 727 trans, first page halfway down, shows a handful of possible levers for the trans.
Second note, if you pull the linkage, at that trans kickdown lever, you can tell it's spring loaded, though only for the second half of it's movement.
Stock adjustments/levers work fine, since the movement is already dialed in. Non-stock, needs the linkage swing, at both ends to be near the same. Just need to match them, even if an adapter is needed at the carb linkage arm. The more complicated the linkage is, more adjustments, to get the same results.
WOT at the carb, should give full swing at the trans lever, with a little play.

 

[AR67GTX]

Another issue may be that a lot of us are running Edelbrock carbs (as I am) instead or original Carter AFB/AVS carbs. I'm not sure if the Edelbrock linkage adaptor matches the throw and radius of the original Carter linkage exactly. I have both out in the garage so maybe I need to measure them.