70 340 6 pack kickdown rod too short

My kickdown rod is too short and seems to be making the car not kickdown and idle high. Where can I get a new correct one piece one for a 1970 that will work better?

Do you have the 3 piece or 1 piece kickdown set up?

It’s the factory 1 piece setup for 1970 340 six pack.

Why do you think the top rod is causing a high idle? From the pic you posted there is plenty of room in the top rod slot for the carb lever to come forward and idle down.

I don't. Shortly after posting the pic I realized it isn't based on the physics of it. The trans rod is too short though and I think and hope that is the trans kickdown issue. Otherwise I don't know.

High idle is still an issue and I'm still stumped. When it's warm and I can manually make sure it's down to normal curb idle around 1100. If not and I just drive it normal and then check it's 1500+. Don't see any hangup otherwise.

Not sure you have the kickdown adjusted right. This video touches on it. At around 8:47 discusses adjusting 1 pc linkage

https://www.youtube.com/watch?v=FY9WTWayCC8

What have you done to adjust idle? You can disconnect the kickdown rod away from the throttle and adjust there. This will eliminate any chance of the rod influencing the idle. Just put on the throttle return spring. Idle issue is not with the kickdown rod. I don't know if you get the carb linkage stuck on high idle cam on the other side or something binding. You should be able to get it down to 900. Doesn't look like the idle solenoid is touching the adjust screw, so that is not the issue either. How do you "manually" get it down to 1100? Then of course, what tach are you using. My stock one reads a bit high, I use a digital one on my timing light for better reading.

Have somebody sit in the car and floor the throttle then, from under the hood, push back on the carb lever to be sure it is at WOT then push back on the trans linkage rod to see how much travel is left at WOT; if there's more than 1/8" or so of remaining travel the linkage is the reason for no kickdown.

Haven’t checked yet, but if it’s not the rod then what might it be?

Fix each issue separately. Disconnect the kickdown linkage from carb. Reattach throttle return spring and see what the idle issue is. 1500 is way too much unless you modified your motor above stock spec.

Once you have idle fixed, then reattach kickdown linkage and adjust it. You should send a photo with top view of of your linkages. I think its just adjustment for trans. You do know there is adjustment for the kickdown as seen on video. You do need to see if you are getting WOT and you said you haven't checked. Need to report that you did check.

Without being there, hard to tell what your issue is. I mentioned if your fast idle cam is interfering with your warm idle performance. Fast idle cam is used when cold and choke closed. If that stuff is not sorted, then that will contribute to fast idle that you cannot get down.

Supposedly stock and I have no reason to doubt that. I will recheck idle and send photos of linkages. I think I might be able to put a spacer in to let kick-down happen sooner??? I put the pedal as far to the floor as possible and no downshift.

as has been mentioned idle and kickdown are most certainly two different isues.
As have been mentioned already have someone sit in the car,engine shut of,with pedal to the floor check how much more you can push the kickdownlinkagerod back from that possition.
I dont have a clue how your linkage looks or is supposed to look but dont ever belive its right just because its supposed to be right,probably dont need to be correct either to work right.
is there no adjustment of kickdown down at the kickdown lever on the transmission?

Regarding idle,i would look for a vacumleak or timingisue.
Dont know what is a correct idle but i cant see why a stock 340 cant idle at 7-800 or so rpm warm.

Did a check. Flooring the throttle definitely pushes the kickdown rod back as far as it can go and NO kickdown.

Will the kickdown adjustment work or is it maxed out for longest travel?

When it is floored by someone in the car, did a second person push the throttle further back? If a person can push it back farther by hand, that means throttle cable is not pulling it all the way back.

Definitely looks like your out of adjustment as far as length

And the angle on that bracket where your adjustment bolt is looks a little steep ‘

Can’t go any further back.

Out of adjustment how?

You answered your own guestion

Can’t go any further back

So out of adjustment as far as length looking at the rod and adjustment bolt in that one picture

And the angle on that bracket looks steep where the one piece rod attaches to that bolt

You positive it’s the correct one piece rod ?

Not sure I understand or maybe I didn't explain what it's doing correctly. I have no idea if it's the correct rod or not since it came to me this way but I can say that it looks like all the other rods I've seen on any other stock automatic T/A or AAR and also what I've seen in the service manuals.

Everything seems to be adjusted correctly even though some angles may look a little steep.

When someone floors the gas the carburetor goes WOT AND the rod is pushed back as far as it can go and it completely pushes in the kickdown valve to where IF the transmission could kickdown it would, but it won't. To me that means the issue is not the rod it has to do with the transmission itself.

What's the next step?

What’s my next step?

Confirm that the kickdown lever at the trans is attached and moving correctly.

Looks to be

I'm not sure where to go from here.

I believe I have the correct parts.

Everything appears to be adjusted correctly.

but NO KICK-DOWN

All shift points are within spec under light throttle.

Under full throttle at low speed no kick-down.

Start in 1 and floor it slap stick moves to 2nd by itself prematurely. Looking at the underside everything looks right. I'm perplexed.

I'm in the DFW TX area.

If anyone knows of someone who can help sort out these issues, please let me know.

The shifter is moving by itself? You have broken motor or trans mounts.

How do I verify/where do they usually break?

Next steps are

At WOT disconnect the linkage at the transmission and verify the arm can't move any more.

If it can then the linkage is getting bound up or is hitting the body

If it can't you either have a transmission issue or a manual valve body.

Also if the slap stick is moving by itself that's an issue like he said

Here’s a pic of an NOS rod, part number 3577529, with the correct length.

I have been following this post hoping to learn something as deciphering these rods can be really difficult. I have posted a picture of what I tagged a while ago as a small block kick down rod, but I don't really know what the actual application is. Compared to the one above, It is pretty much the same length, but seems to have a little different bend locations.

The NOS kick down rod part number 3577529 in the previous post, according to the parts books is the correct part for the 340-6 AARs and T/As.

What's is interesting is that the part number 3577529 carried in to 1972 model year and was found on B-Bodies with a 318-2 engine.

440/383

So many choices

Does anybody reproduce the AAR/T/A rod?

Yes and they are $$$. Year One, Herbs, aa and a etc. $350+

Take off your one piece rod and compare it with that one NOS Rod Picture posted here if you want

The $350 reproduction kit is for everything , and if your one piece rod is the correct one installed compared to that NOS piece , its time to look at other things like your internal valve body

Next

While your under there by the transmission

Take the throttle lever on your transmission and move it backwards within its full travel with your hand

You should feel some resistance as you move it rearward , probably around halfway of its travel , from the internal spring within the valve body and see how it feels

Here’s my kickdown rod

We are still waiting for you to tell us what the kick down lever on the transmission feels like.

The rod you have looks like the NOS and if anything it might be too long by a 1/2" - so I don't think it is your issue

You also have not answered the question of if your slap stick is moving on it's own from 1 to 2

I must have missed it. Feels like how? It does move by itself from 1-2.

Put the car up on stands and use a jack under the tailshaft and jack it up to see if the trans mount separates, then do thd same on each side of yhe engine. If it's shifting by itself you almost have to have broken mounts or bolts missing.

Exactly!

If this is happening all the geometry goes out the window

The rod he pulled off is not the same as that NOS one in that picture unless

Unless my eyes are deceiving me , it looks to Bee almost an inch short , and then look at the 22" mark on his where the bend starts compared to the same 22" mark on the NOS 3577529 it stays straight thru 23 1/2" then the bend starts

Anyways

Let’s compare rods - Lol

Here’s some closeups showings overall length

Also looks like the NOS rod is linear and flat where mine is twisted and bent upward from laying flat. Since it’s all about geometry I can’t help but think all the bends and twists in mine have a negative impact on performance. The one I have is short but not by 2 inches mentioned previously. More like half an inch, but I wonder about the bends and linear movement. Anyone know where I can get a new NOS one like the blue one?

bump

You seem to be focused on the length of the rod but, as you've stated, the trans lever is full back at WOT so the point is moot.

What you should be focused on is the "Start in 1 and floor it slap stick moves to 2nd by itself prematurely.".

Checked mounts they are good. Today I reinstalled the rod after I tweaked it so it was the same length as a stock one. I was playing with the shifter handle and noticed that sometimes I couldn't get it to fully go into 1. So I drove it. When I would put it down in 1 once I got it to fully go I noticed the accelerator pedal was almost impossible to press. I brought it back and took a look under the hood and the shift linkage and kickdown rod linkage are interfering with each other. So this must be why when you floor it in 1 it automatically moves to 2 because the kickdown rod is pushing the shift selector to the next gear. How can I fix this?

Check the shift linkage for loose or missing plastic bushings, they're known to fall out.

has it but its not that color.

color doesn't matter if the bushings are there and snug.

I think I may remove the anti-theft column lock rods and see if that helps

Yours are probably white

Do you have a 2nd person to watch what is going on? Have someone push the kickdown linkage back and forth and see what is happening down below. Is it binding on something? After you "tweaked" it, now you can't push on the accelerator. Sounds like it got worse when you adjusted the rod. Almost sounds like the kickdown is not attached at the right place. Do you have a photo where the kickdown is attached to the transmission? The kickdown lever hitting the shift lever at transmission?
While car is on ramps or stands, put trans in 1st gear, move kickdown lever back and forth and see what is happening below. Use wheel chocks. Quick article about kickdown and different length levers.

https://www.hotrod.com/articles/the-lowdown-on-stock-torqueflite-kick-down-linkage/

I believe the intereference of the column lock rear rod in the attached photo that is an anti-theft mechanism has been the issue with it automatically shifting from 1-2 the whole time. I had someone tell me to remove this rod and it would likely solve my issue.

Yes

If you remove the lock rod remember to set the lever at the bottom of the column or the ignition will lock.

Are you sure you have the correct throttle pressure kick down lever attached at the valve body? There are different lengths. This would change the attaching point distance of the rod. Maybe it got switched out during a trans overhaul?
Doug

I'm not sure of anything. How can I tell.

I'd have someone with a working set up measure theirs.
Doug

Good Read with some pictures on the factory stuff so you can understand what your looking at with different length throttle levers and adjustment , never mind the Lokar cable setup mentioned in the article as that is an aftermarket set up

Click on link


https://www.hotrod.com/articles/the-lowdown-on-stock-torqueflite-kick-down-linkage/

Not sure I understand please explain.

The lock rod moves part of the column that allows the ignition to turn. It is an safety device the car from being started when in gear. Play with the lever and the ignition switch and you will see what I mean.

If the lever on the lower column is down you can't get the key out. Ask me how I know this.

Does the rod need to be all the way up or all the way up or all the way down for everything to function?

Look at the position the lever is in when the car is in park. That is where you need to put it after you remove the rod.

That rod is already out but the way it looks to work is that when the car is in 1st it pushes the lever all the way forward which would push the rod all the way up and the part on the column would go all the way to the top so in park it would be at the bottom.

I've tried the key with it all the way up and with it all the way down. Makes no difference on key operation, insertion or removal and no difference in steering column or wheel operation.

Then someone was already into the column. Which means you got lucky. At least now if you have trouble working the key you will know where to start looking.

When the rod was connected it did what it was supposed to do. It would require the steering wheel to unlock to be able to shift out of park.

Today was the first chance I had to test it out and WOW! It actually kicks down now and shifts appropriately and is able to go wide open throttle giving a ton more power. When it kicks down it actually spins the tires. So grateful thanks for all the help. I've been battling this issue for years and all because of this simple little rod.

Good news.

always feels good when a problem gets fixed, don't it ? good deal on the fix !