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Please educate me on 727 throttle pressure. (I have no kickdown)

Jonas Nordstrom

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Ok, I very carefully installed my wire set-up on my 727, making sure the hole on the carb lever was exactly where it should be (I took the special mopar bouchillion throttle plate to double check with.)
I tested several arms (Different lengths) down on the throttle lever on the 727.
I got a perfect ratio adjusted now when the pressure lever almost bottoms out when the carb lever is fully open.
The 727 changes gears just when it should at the right speeds. No slipping etc.

Though I have no kickdown...

Is it time to remove the oil/cover on the 727 and adjust inside there?
(And what/how do I adjust that?)

pressure.jpg
 
Following ..I have the same issue.it upshifts and downshifts great . But no kickdown when getting on the gas .
 
I had this issue on a early 727. It had a crack in the valve body wall next to the throttle pressure valve. Take pressure test at the accumulator. Move the throttle pressure arm rearward. You should see 95-100 psi fully rearward. If it's low you have a valve body issue.
Doug
 
Throttle pressure has to overcome governor pressure to upshift or down shift. The relationship you want is at idle the throttle lever is just touching the throttle valve, and at WOT the throttle valve should just be fully depressed. You have to have this mechanical relationship for the trans to function as designed. Many times I hook up and check the throttle valve and linkage with the pan off before filling with fluid.

If you put a pressure gauge on the governor port governor pressure will roughly equal MPH until about 60 lbs or so. dvw told you how to check throttle pressure. I can't tell you how many times people chase their tails on a problem, and it is fixed with a pressure gauge pointing in the right direction. Harbor freight has very reasonable gauge sets, which can also be used for other things, every wrench should have a set.
 
Ok, I very carefully installed my wire set-up on my 727, making sure the hole on the carb lever was exactly where it should be (I took the special mopar bouchillion throttle plate to double check with.)
I tested several arms (Different lengths) down on the throttle lever on the 727.
I got a perfect ratio adjusted now when the pressure lever almost bottoms out when the carb lever is fully open.
The 727 changes gears just when it should at the right speeds. No slipping etc.

Though I have no kickdown...

Is it time to remove the oil/cover on the 727 and adjust inside there?
(And what/how do I adjust that?)

View attachment 1631052
What year of transmission? 60's and early 70's didn't have a part throttle kickdown. With your throttle completely open, the throttle valve on the transmission should be full open. Double check to make sure the carb is going full wide open with the pedal. If not, adjust the cable accordingly. (you will need a friend to check this out)
 
What year of transmission? 60's and early 70's didn't have a part throttle kickdown. With your throttle completely open, the throttle valve on the transmission should be full open. Double check to make sure the carb is going full wide open with the pedal. If not, adjust the cable accordingly. (you will need a friend to check this out)
It is a -69 box.
The carb is fully open.

During my engine tests with other carbs I have had both low speed and high speed kickdowns, so both are there somewhere.
 
It is a -69 box.
The carb is fully open.

During my engine tests with other carbs I have had both low speed and high speed kickdowns, so both are there somewhere.
My guess is that the kickdown isn't adjusted properly and the lever isn't going fully open especially if it worked before but doesn't now because you changed things.
 
KD has to be set properly at idle... and full throttle
PTK came out in 71
Check pressure with gauge.
 
What exactly was changed since it last worked?
 
Well, there yo go.

That's pretty much what it has to be.
 
KD has to be set properly at idle... and full throttle
PTK came out in 71
Check pressure with gauge.
It is set at idle (barely touching where you start to feel resistance in the throttle lever.)
And then the best change gear adjustment was when the KD lever is about 1mm from bottoming out when the carb is fully open.
 
I would run the adjustment back towards kickdown engagement a fair amount.

Much safer to have it come in too quick and adjust that out, than drive it with no pressure and burn up third gear.
 
Well, there yo go.

That's pretty much what it has to be.
I thought the cable adjuster could fix that but maybe there is something else with the ratio that changes moving the attach-point rearwards?
 
I would run the adjustment back towards kickdown engagement a fair amount.

Much safer to have it come in too quick and adjust that out, than drive it with no pressure and burn up third gear.
I do have it right at where the pressure starts in the KD lever.
Changing gears is a nice "tug" at the correct speeds.
(Dont remember the speeds now but I found them online when adjusting. )
 
I do have it right at where the pressure starts in the KD lever.
Changing gears is a nice "tug" at the correct speeds.
(Dont remember the speeds now but I found them online when adjusting. )
You might not be there yet. It's the wide open adjustment that matters.
 
Thinking out of the box here...
Could I have damaged/bent something in the valve body when testing?
For ex having the cable too short so the KD is bottoming out before fully open carb?
 
Thinking out of the box here...
Could I have damaged/bent something in the valve body when testing?
For ex having the cable too short so the KD is bottoming out before fully open carb?
Probably not. I have never heard of an issue.
 
You might not be there yet. It's the wide open adjustment that matters.
Damnit, I have been adjusting like crazy at WOT.
...starts to feel like its the starting point that is wrong.
What could be the next step, shorter lever down on the box?
 
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