Kickdown fine tune adjustment

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340,
Is there any particular reason you want to extend the shift speed in each gear?
I always went the opposite way for normal driving. Quick upshifts & let the t/converter do the work.
 
Bewy said:
If you want to increase the 1-2 upshift speed, you can do it without removing the pan.
If you have a carb with large throttle bores, it requires less throttle opening than a carb with small t/bores....to get to the same road speed [ shift speed ]. The K/D lever moves less with a big carb, all else being equal; & the trans shifts earlier, all else being equal.
The above demonstrates that it is a 'ratio thing '.

If you want later shifting: there is a rod from the carb that goes to a bracket/linkage at the back of the engine. Where this rod hooks onto the bracket, the hole or stud on that bracket needs to be repositioned closer to the pivot.
The idea is: for the same throttle open position, the K/D lever moves further, increasing line pressure & delaying the shift point. You might need to experiment with different hole positions. The same thing can be achieved with the K/D lever on the trans; move the linkake hole closer to the
Click to expand...

Bewy said:
340,
Is there any particular reason you want to extend the shift speed in each gear?
I always went the opposite way for normal driving. Quick upshifts & let the t/converter do the work.
Click to expand...
Initially it felt like it was starting in 3rd gear, sluggish acceleration no torque it wasn’t winding out at all. I wasn’t getting any 3-2 kick down either. None when I punched it. Just felt like I was always driving around in 3rd. No upshifts felt.

I then tightened the rod about 3/8” and now I am getting it to kick down under WOT properly. I have a lot more torque. I am however still having trouble detecting feeling/hearing the 1-2 up shift. I feel it might be happening right away.

I still and need to drive it more with a tachometer to see what RPM the shift points are at.
 
Bewy said:
If you want to increase the 1-2 upshift speed, you can do it without removing the pan.
If you have a carb with large throttle bores, it requires less throttle opening than a carb with small t/bores....to get to the same road speed [ shift speed ]. The K/D lever moves less with a big carb, all else being equal; & the trans shifts earlier, all else being equal.
The above demonstrates that it is a 'ratio thing '.

If you want later shifting: there is a rod from the carb that goes to a bracket/linkage at the back of the engine. Where this rod hooks onto the bracket, the hole or stud on that bracket needs to be repositioned closer to the pivot.
The idea is: for the same throttle open position, the K/D lever moves further, increasing line pressure & delaying the shift point. You might need to experiment with different hole positions. The same thing can be achieved with the K/D lever on the trans; move the linkake hole closer to the
Click to expand...

JDMopar said:
When you have it adjusted properly, under normal driving conditions, it should shift from 1-2 at 18 mph and from 2-3 at 28 mph. If it is short shifting (too early) make the rod longer by unscrewing the adjustment at the carb. If it is holding too long and shifting late, shorten that same adjustment a few turns at a time to get it dialed in. Obviously, the more you mash the gas pedal, the more throttle pressure the valve body sees and will hold shifts longer, as it is designed to do. You do not want to lengthen the throttle pressure linkage to the point that it keeps the carb butterflies from achieving wide open throttle, like @RustyRatRod advised above. It is also important to have a small spring pulling the throttle pressure linkage forward towards the carb stud that pushes it backwards. If there is a gap between the stud on the carb and the linkage slot, the valve body isn't seeing any pressure applied from idle to wherever the stud finally catches the slot and starts pushing. Go back up to post #2 and look at the pic. See that little triangle shaped tab welded to the kickdown rod? The little spring goes in the hole in that tab and hooks to the end of the carb stud to hold the adjuster to the rod at all times. Keep plugging at it, and you'll get it figured out.

:thumbsup:
Click to expand...
Thank you yes I need to check that the carb secondaries are being blocked with the latest KD adjustment as Rusty suggested. Wasn’t able to do that today as I had to paint some parts.
 
Bewy said:
340,
Is there any particular reason you want to extend the shift speed in each gear?
I always went the opposite way for normal driving. Quick upshifts & let the t/converter do the work.
Click to expand...
Read the thread, Sparky. He's said all along it shifts way too quickly and doesn't down shift properly. Both indicative of low throttle pressure. If he doesn't fix it and SOON, he'll be puling the transmission for a rebuild. I hope it's not too late now.
 
RRR,
I did read the thread. I like my auto trans to upshift early, & I doubt I am the only one. And they didn't burn up or blow up. I simply asked the question. Get over it.
 
Bewy said:
If you want to increase the 1-2 upshift speed, you can do it without removing the pan.
If you have a carb with large throttle bores, it requires less throttle opening than a carb with small t/bores....to get to the same road speed [ shift speed ]. The K/D lever moves less with a big carb, all else being equal; & the trans shifts earlier, all else being equal.
The above demonstrates that it is a 'ratio thing '.

If you want later shifting: there is a rod from the carb that goes to a bracket/linkage at the back of the engine. Where this rod hooks onto the bracket, the hole or stud on that bracket needs to be repositioned closer to the pivot.
The idea is: for the same throttle open position, the K/D lever moves further, increasing line pressure & delaying the shift point. You might need to experiment with different hole positions. The same thing can be achieved with the K/D lever on the trans; move the linkake hole closer to the pivot.
Click to expand...
I don’t think you can’t really do this as it will inhibit full throttle travel as the the kick down lever will be full open (pushed all the way to the back of the car) before the throttle is fully open. Once the tv lever is fully open it will prevent the throttle from moving further back

With the Lokar set up I used and Dakota lever the ratio is perfect at 1:1. They work in unison and arrive at full open at the same time
 
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That is why I said in post #23 it is a ratio 'thing'. You have to experiment. That is what hotrodders do when they are unhappy with the status quo......
 
340 Just wondering if this transmission is being installed with the 340 you were working on to get dialed in? If so a stock transmission, converter and rear end gears come into play here I would think.

I'm not questioning any of the other replies here, good info was relayed.
 
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Darter6 said:
Common practice for those that don't know proper adjustment techniques.
Click to expand...
I had a 727 rebuilt, by a Chevy guy and he did this. I never got a good answer why, but it's been working great for a couple years now so I'm leaving it.
 
Mojoe9955 said:
I had a 727 rebuilt, by a Chevy guy and he did this. I never got a good answer why, but it's been working great for a couple years now so I'm leaving it.
Click to expand...
It has the wrong length rod in it somewhere, so the nut and bolt make up the difference.
 
Mojoe9955 said:
I had a 727 rebuilt, by a Chevy guy and he did this. I never got a good answer why, but it's been working great for a couple years now so I'm leaving it.
Click to expand...
I guess it's the old saying "If it ain't broke,don't fix it.!"
 
just so you guys don’t think I’m lazy…… size does matter she was right. But she didn’t know geometry also matters.

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Got the 904 with the 340 kickdown adjusted for the 3-2 downshift nicely. Where can I find information on how to finally tune it for the 2-1 downshift? Or can anyone explain how that gets done once it set up for 3-2 downshift? Should I bring it a bit sooner? It’s not like there’s multiple handles here.
Click to expand...

I dunno exactly what you are asking but maybe this will help;
If you get the 2>3 working nicely, but
the 1-2 is too early or too late, the only option is to change the 1>2 shiftspring.
This happened to me, with my 318-4bbl powered winter combo, and that is what I did.

IMO, this may be related to the fact that for all Torqueflites, the shiftsplits are NOT the same, but IDK that for sure;
1>2 is 1.45/2.45=.59 and
2>3 is 1.00/1.45= .69
The factory auto-shift calibration is pretty good for most of the time, but the WOT upshift rpms rarely match. If yur looking for that last lil bit of power, you gotta hold it with the manual shifter........ or fudge with the 1-2 spring.
What I discovered tho, is that when I did that, this also changed the 2>1 auto-downshift, which in my case, I really liked it.
I used to have to manually downshift for certain corners, before I got there, to be ready to power out of the turn. This was always a herky-jerky affair, so I had to do it before the turn, to prevent sliding.
After the change, now I go into the same turns in Second, and mid-turn, as I begin to lay on the power, bam the trans drops into First, all by itself, exactly at the right time! runs up to shift rpm, shifts, and we are outta there. and I never had to let go of the steering wheel.
But yeah, mine also has the PT kickdown, which now, actually works, which device can be retrofitted to any Torqueflite 67 or newer.
Oh and also worth mentioning is that my 904 runs a 2800 Stall. booyahh
 
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AJ/FormS said:
I dunno exactly what you are asking but maybe this will help;
If you get the 2>3 working nicely, but
the 1-2 is too early or too late, the only option is to change the 1>2 shiftspring.
This happened to me, with my 318-4bbl powered winter combo, and that is what I did.

IMO, this may be related to the fact that for all Torqueflites, the shiftsplits are NOT the same, but IDK that for sure;
1>2 is 1.45/2.45=.59 and
2>3 is 1.00/1.45= .69
The factory auto-shift calibration is pretty good for most of the time, but the WOT upshift rpms rarely match. If yur looking for that last lil bit of power, you gotta hold it with the manual shifter........ or fudge with the 1-2 spring.
What I discovered tho, is that when I did that, this also changed the 2>1 auto-downshift, which in my case, I really liked it.
I used to have to manually downshift for certain corners, before I got there, to be ready to power out of the turn. This was always a herky-jerky affair, so I had to do it before the turn, to prevent sliding.
After the change, now I go into the same turns in Second, and mid-turn, as I begin to lay on the power, bam the trans drops into First, all by itself, exactly at the right time! runs up to shift rpm, shifts, and we are outta there. and I never had to let go of the steering wheel.
But yeah, mine also has the PT kickdown, which now, actually works, which device can be retrofitted to any Torqueflite 67 or newer.
Oh and also worth mentioning is that my 904 runs a 2800 Stall. booyahh
Click to expand...
Thanks AJ. Is that a compression spring? Are there different springs available to use? Kit? Also if it shifts to early is that less spring pressure to overcome to shift?
 
Darter6 said:
Common practice for those that don't know proper adjustment techniques.
Click to expand...
Or sometimes when you put a 4bbl on a 2bbl car and the linkage is for the 2bbl. The 4bbl Mopar throttle stud is in the wrong place for that and sometimes you cannot adjust it without adding a bolt and nut. I'm sure there are other examples but this is one of them.
 
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