Scout II 727 kickdown linkage -- how the heck does it work?

[Chris Pucci]

I think I have all the pieces and it is all stock'ish as far as I know...

How does it work? How does it hook up? How do you adjust it so it works correctly?

I thought I had it hooked up properly but upon starting the truck I realized that it was holding the throttle at wot!!! Holy crap not a good idea...

 

[Michael Mayben]

Chris,

first off, review some info in this thread for the throttle pressure (kickdown) adjustment sequence:

http://www.forums.IHPartsAmerica.com/transmission-tech/588-torqueflite-727-guapo.html

Here's a pic I took of a virgin sii kickdown assembly at ihon in October. It's a rig that is waiting for a new home and is complete and unmolested under the hood. Unfortunately it does not show the system in entirety, I have other pics of a fullsize linkage but since it's different, I don't wanna confuse ya! This pic is with the throttle closed (engine stopped).

There is a considerable difference in the "kickdown" linkage between a fullsize like your old pickup, and the way it's rigged on a Scout II. But if your bro's sii you are working with is/was complete and shifting properly before the tranny swap (and I know it was), then all that should be required is putting it together properly, and the making the adjustment.

On the sii, when the engine is not running, then the throttle pressure control (kickdown rod) should be all the way "forward". The lever/valve down on the tranny is spring-loaded (internally) to the "minimum" position and must be free to move in coordination with the throttle linkage as it moves to the rear when the throttle is opened from idle position.

On the sii linkage that is mounted on the intake manifold, the lever on the side away from the fender is "clamped" to the cross shaft with a pinchbolt arrangement. This May have come loose, or was improperly adjusted before ya started messin' with it!

The simple way to look at this...with the throttle closed, the kickdown should be all the way forward (with plenty slack) in the minimum pressure position. As the throttle opening is increased, the throttle pressure (kickdown) is increased also in proportion to movement. When the throttle is wot (make sure the cable is adjusted to allow that!!), then the kickdown rod should be all the way back but not hold the lever on the tranny hard against it's internal stop. If it's a "hard stop", then that quickly wears the smaller seal on the shaft (which is new in your case), and puts a lotta mechanical pressure against internal components of the valve body.

There is also a small, light "anti-rattle" spring on the flat slider link part. That keeps the "slack" in the mechanism to a minimum and must be in position for proper actuation.

 

[Michael Mayben]

Here's a pic of the anti-rattle/tension spring I mentioned in proper position. That spring is not a "calibrated" tension, it just maintains contact with the slider and the throttle control so it doesn't have any slack in it when in operation.

 

[Michael Mayben]

The threaded clevis is to allow "fine tuning" of the throttle pressure system after that pivot arm which is clamped with the pinchbolt is positioned.

Here's one last shot of the assembly.

 

[Chris Pucci]

Everything looks like the pictures -- just when I popped the lower end of the linkage into the arm on the tranny it pushed the throttle open -- rather than still have slack in it.

And - when I pulled the tranny the linkage was not connected at the tranny - so I have no idea if it was working properly before at the bottom end.

Could the arm be bent?

 

[Michael Mayben]

Iirc, the rig under discussion had tranny issues way back when, we just never got around to dealing with it before your bro moved it south. That's why when you recovered it for the reconstituting, I suggested monte's tranny as a cost-effective solution since it's a known-good unit.

So now let's just make the linkage right, no doubt it's been mis-adjusted at some point.

Set the adjustable clevis to about the same "stick-out" as the one shown in the pic I posted. Leave the tranny lever end dangling and disconnected.

Hook up all the throttle control linkage at the carb end just like it's supposed to be, complete with the tension spring. Adjust the throttle cable so it closes completely and opens completely, if the throttle pedal arm is bent/weak, that needs to be repaired first or ya can't get the throttle cable properly adjusted. I know you have experience with that known issue!

Then, loosen the pinch bolt on the clamped arm and "twist" the bellcrank end where the clevis is so that the rod falls right into the hole down on the tranny-mounted throttle pressure control lever. You'll notice that the lever has quite a bit of "slack" in it before it contacts the valve inside the valve body. It's supposed to be that way. Remount the kickdown rod using the clip.

Now...with the throttle closed, the kickdown rod should be all the way forward. As the throttle is opened by the cable, then the kickdown rod moves to the rear in proportion to throttle lever travel.

Simple operation of the kickdown...as the throttle is opened allowing more engine power to be produced, then the throttle pressure control increases internal tranny line pressure in proportion. This "proportion" is already worked out when the engineering was done on the system! You can "adjust" the line pressure by fine-tuning the clevis "stickout" after the entire system is set up in it's "base" form.

The shift points of the tranny up and down are controlled /determined by the combination of the variable line pressure (based upon throttle position), internal valve body calibration, and the position of the governor components within the governor body on the output shaft. It's much more complex than that actually, but that tells ya basically how it works!

Here's one more shot for reference, this is ken's virgin sii (the babyshit yeller one) before I did the 2300 centerhung carb conversion, this one is set up with an aftermarket cruise control also.

If ya still can't figgr it out, I'll take a look towards the end of this week when I bring ya the hub/pulley set and recover the trailer!

 

[Chris Pucci]

iirc, the rig under discussion had tranny issues way back when, we just never got around to dealing with it before your bro moved it south. That's why when you recovered it for the reconstituting, I suggested monte's tranny as a cost-effective solution since it's a known-good unit.

So now let's just make the linkage right, no doubt it's been mis-adjusted at some point.

They had the tranny out 2-3 times. The engine out. Swapped a manifold, swapped a few carbs, etc, etc...

And for the record it has always been down south - I think since my brother has owned it has been about as far north as sacramento and as far south as san jose, I doubt it ever made it as far west as san fransisco :d...

 

[Michael Mayben]

I thought when we first talked about this rig way back when it was at your Mom's place up here! Good thang I never offered a "service call" back then!

Hail...when we lived down in the east bay, I was just over the hill from walnut crick! In el sobrante.

 

[Carl Wiese]

Step one: get rid of stock IH linkage and give it to mayben to keep. He like archaic and rube goldberg type thingamajigs!

Step two: go buy a lokar 727 kickdown cable. If you really want a smooth easy working, easy adjust and setup, buy the throttle cable too.

Step three:read my newsletter article on installation. Install in about 2 hours and enjoy for a life time.

 

[Michael Mayben]

The rube goldberg kickdown shit is what was on the late '73>'75 fullsize stuff for the fookin' 401 rambler motor apps and then carried over onto the IH sv apps with the 727. The Scout II platform never incorporated that shitpile kickdown setup developed for the rambler 401 motor. And we're very fortunate them motors didn't make it into sii stuff except for the 258 6banger.

I will agree that the lokar cable systems are class acts, that's why ihon is a dealer for that stuff!

That rambler kickdown shit if used today would generate a massive nhsta mandatory recall, it's flatazz dangerous to drive!

In my book, there is nothing wring with the sii kickdown linkage if it's complete and adjusted correctly. If it's got po virus though, the lokar system is much nicer to deal with than come up with all the bits and pieces for the sii oem stuff. And that is complicated by having several different carburetor linkage "links" that were marked specifically for each engine/carb app that with the common components used on all versions.

 

[jtownley]

Mike,

glad I found this thread. Hoping you can give me some guidance because I'm at a complete loss.

Here is my application. I have a 71 800B with a 304 and a 727 that someone swapped in along the line. This Scout also has a Holley projection unit. The accelerator rod appears to be the original stock unit with a fabbed bracket hooking it to the Holley. The kickdown rod is there, but not hooked up to the throttle currently. I found what I thought is the necessary parts on ebay (or somewhere) to get the kick down hooked up, but I'm having problems visualizing how it should be hooked up.

I have attached some pictures of the engine bay of my Scout and the part I am trying to get attached. I believe that I just need to take that sliding bracket off of the spare part and attach it to the like part in my Scout, but I can't see how it attaches to the throttle and how the springs would work.

Also, how much should that kickback rod move back and forth? If I work it manually by hand, it only moves an inch or two front to rear.

Any advice that you could offer me would be greatly appreciated.

Thanks, john

 

[Michael Mayben]

Some comments...

1) is that electric throttle kicker I see in your first pic functional? If so, is that to kick the idle speed up for an a/c (or air) compressor engage action??

2) the actual kickdown control "rod" that goes down to the transmission throttle pressure control lever can't have anything touching it, make sure that the heater hose makes no contact whatsoever throughout the range of movement. And since you currently have no throttle pressure control to your trans, it stays in "minimum" pressure mode which in turn is not good for the trans and it can't shift properly.

3) what you have rigged right now for a "throttle return spring" is really dangerous in my book! You need a much more positive spring leading forward. And trying to run that throttle body off the oem-type accelerator pedal/rod system is asking for major bind-up. There is way too much friction and slop associated with any ihc "rod-type" oem throttle pedal/control system to make it safe in my opinion. And being able to precisely control throttle lever position is near impossible.

4) the donor kickdown control system is designed for an oem throttle cable system as used in Scout II and fullsize stuff. Your current throttle rod-operated system is going to be a bitch to try and set up correctly due to the "l" bracket adapter for the threaded end. I'm not saying it couldn't be done, but in my opinion it's simply not worth the effort and it's going to take some significant fab work to make it safe.

5) to use the oem Scout II kickdown sliding link (the flat steel item with the slot), the throttle arm had a ball stud with a "spacer" that allowed that slot to engage and slide in a sloppy manner to prevent binding. And the arm that is clamped to the bellcrank was made to be able to "adjust" the pickup point for the kickdown as the throttle arm opened.

I really think you would be much better off setting up the lokar cable throttle control and kickdown control! For the injection stuff to work really well, the throttle control can't move in a jerky/binding fashion or the computer will continuously hunt trying to compensate for the erratic throttle plate angle. And....that gives absolutely perfect setup for the throttle pressure control (kickdown) for the trans which is imperative for proper operation and longivity!

Basically, the throttle pressure control needs to operate in perfect synch with the movement of the throttle lever on the throttle body. When it's at idle, the throttle pressure is at minimum, at wot, the throttle pressure is at maximum.

I've been working with a guy here that has a very similar issue going on with a '66 t'all that uses the same throttle rod setup on a new Holley carb. And the fabricator has installed a lokar kickdown cable also. But...the two systems do not operate in synch and the carb throttle arm was only going a little more than 1/2 travel! So therefore, the transmission could not shift correctly, either "up" or "down".

The fabricator has now corrected the linkage and the owner will bring the rig back to my shop this weekend so we can do the final setup on the carb and verify correct transmission operation for the final time.

 

[jtownley]

Mike,

thanks for the quick and detailed reply, it is appreciated.

No air compressor of any kind on this Scout. That electronic device is a "fast idle solenoid" that comes with the projection kit. It's purpose is 2-fold. On cold starts, it engages to bump the idle a bit. Also on deceleration, it engages to allow for smoother deceleration.

My ultimate goal is to get the lokar set up. Do you know if Jeff has these available for sale? I've looked at the kickdown unit that they offer (part number is sitting on my desk in the office), and it looks to be a universal fit type of deal. Is the accelerator cable similar? With this setup, will I need to change out my pedal?

I'm just trying to see if I can get this unit working in the mean time.

Thanks again,

john

 

[Michael Mayben]

Mike,

thanks for the quick and detailed reply, it is appreciated.

No air compressor of any kind on this Scout. That electronic device is a "fast idle solenoid" that comes with the projection kit. It's purpose is 2-fold. On cold starts, it engages to bump the idle a bit. Also on deceleration, it engages to allow for smoother deceleration.

My ultimate goal is to get the lokar set up. Do you know if Jeff has these available for sale? I've looked at the kickdown unit that they offer (part number is sitting on my desk in the office), and it looks to be a universal fit type of deal. Is the accelerator cable similar? With this setup, will I need to change out my pedal?

I'm just trying to see if I can get this unit working in the mean time.

Thanks again,

john

Ok, the throttle kicker (fast idle solenoid) is part of the Holley efi stuff then! So the projection must not use an iac or other methodology for "regulating" idle speed. Those are also an accessory part that Holley (and others) offer for a throttle kicker when using a carburetor. Similar devices were used on some of the '73 and later fullsize and Scout II carb setups oem only used as an "anti-diesel" solenoid to prevent "run-on" when the ignition was killed and the engine hot.

Yes, ihon does stock both the lokar "universal" transmission kickdown cable and the universal throttle cable.

To use the throttle cable with your existing pedal "lever" that comes up out of the bulkhead, you will have to fabricate a cable housing "stop". And the throttle cable will be real short, the challenge will be in getting the travel of the cable and throttle pedal correct for the travel of the projection throttle lever so that it will have slack in the cable at idle, and allow wot.

This pic shows a typical lokar cable set on a t'all that had a throttle cable oem. This rig originally had a kickdown setup that is far different than found on the '74/'75 t'alls that carl referenced. This one was done about a year ago by my buddy ccctrumpet here on the ihon and is connected to an edelbrock 1406 carb.

I simply don't have a decent pic of an actual Scout II oem kickdown control, while the principal is the same as the fullsize stuff, the execution is a bit different.

 

[Chris Pucci]

Here is a lokar setup on a Scout II:

I don't have a stock kickdown picture either - it was half missing when I started the lokar install, hence the reason for the swap.

 

[Tiny Yokum]

Solved my problem. Thanks Mike. This is my throttle system restoration with some mods on a 345 Thermoquad 727
.