Should there be play in the kickdown linkage? (727)

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Corrupt_Reverend

Corrupt_Reverend

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First off; When it comes to transmissions, I'm dumber than a bag of hammers.

So I'm getting ready to swap motors tomorrow and while I was pulling everything off the old engine, I noticed about a quarter inch of back and forth play in the slotted linkage bit that connects to the carb. The PO had a bolt and nut in the slot to limit it a bit, but it's still slides back and forth.

If it helps, I can take some pictures.

Oh, also it's got an edlebrock intake and carb if that matters.

So how much play is normal?

Thanks,
~Rev
 
Yes there is play in that slotted rod. You should be able to push to the rear on that rod and feel a little resistance and then when you let off the rod it should want to spring back forward. Do this with the spring that returns the throttle pressure rod removed. ( the one up top). And yes post a picture of what you have
 

the slot is so if snow gets packed on the linkage on the bottom it does not hold the carb open. it happened to me on 54 new yorker powerflite linkage. so thank your chrysler engineers
 
SGBARRACUDA said:
Yes there is play in that slotted rod. You should be able to push to the rear on that rod and feel a little resistance and then when you let off the rod it should want to spring back forward. Do this with the spring that returns the throttle pressure rod removed. ( the one up top). And yes post a picture of what you have
Click to expand...

Exactly, and I'll add that the screw was put in the slot to increase line pressure in the trans sooner causing the shifts to be later and firmer.
Problem is that sometimes the way people do that also can limit wide open throttle by not allowing the throttle plate linkage to swing full travel.
(throttle doesn't open all the way)

That forced me to come up with another simple solution to raising throttle pressure sooner that does not limit the throttle opening.
It's just a small spring that makes the normal rod lead the throttle a little, but still lets the throttle open all the way.

This was my old 2 barrel but I have it one the Eddie 4 barrel now.
 

Attachments

Okay, here's a few pictures.

This first one shows a side view of the linkage conundrum. Yes, that is a hose clamp being used to "retain" the slotted linkage bar deally.

8EzCXjF.jpg


This nex one shows the same but from a top view. Here you can see the nut and bolt that was apparently used to limit how much travel there is in the slot? I don't pretend to know how this is supposed to work. Maybe it's supposed to be there?

3u1cxZj.jpg


This last picture shows the shenanigans going on at the back of the linkage. I'm pretty sure this aint' kosher. There's a smaller spring that connects from the top of the linkage that goes down along the firewall, to the plug-wire organizer...

oOAeocN.jpg
 
Taking that bolt out is going to let your throttle open all the way, but it's going to shift early and really soft compared to what it does now.
Assuming the rest of the trans works like it should.

I'd bet your throttle only opens about 2/3 of the way right now, if that.

Oops, I fixed "should'nt" be there at all.
 

Attachments

TrailBeast, you're a champ! Big thanks!!

So, what about the spring at the back in the last picture I posted? Is that supposed to be there?
 
Also that spring in your last picture is suppose to hold the linkage at the firewall in the forward position. It is suppose to attach where that hose clamp is.
 
So is this how the rear spring should be connected?

That picture came up after searching "torqueflight 727 throttle pressure linkage".
 
Corrupt_Reverend said:
TrailBeast, you're a champ! Big thanks!!

So, what about the spring at the back in the last picture I posted? Is that supposed to be there?
Click to expand...

That's about the right spring but it doesn't look like it's doing much the way it is.
The spring should hold that rod all the way forward with just enough pressure to return it and hold it forward when the linkage moves around (so techinically the back of the slot in the rod should be all the way forward up against the connection rod for the throttle cable)

It should be adjusted so that they both (throttle and TP rod) and each move to full rearward travel all the way.

My spring is doing double duty for the cotter pins on each rod (throttle and the firewall end of the TP rod.

If after all this you would actually like the shifts a bit later/firmer and still have a throttle that open all the way, it is shown in the pictures I posted above.
It is the absolute simplest way I have found to trick the trans into thinking you are on the gas more than you actually are, and therefore shift later and firmer.
 

Attachments

Corrupt_Reverend said:
So is this how the rear spring should be connected?

That picture came up after searching "torqueflight 727 throttle pressure linkage".
Click to expand...

Personally I don't like the rear connection point of the spring in that picture.
It might be enough with that spring, but it should be higher up the arm and not in those holes at the bottom.
That's why I chose to use the cotter pin hole.

Other than that it's a great representation of the layout.
 
TrailBeast said:
Personally I don't like the rear connection point of the spring in that picture.
It might be enough with that spring, but it should be higher up the arm and not in those holes at the bottom.
That's why I chose to use the cotter pin hole.

Other than that it's a great representation of the layout.
Click to expand...

I think I'll go with your advice and use the cotter-pin hole. Thanks again. :)
 
I'm not crazy about a couple of things there. First, I think you need to get the throttle cable out from behind the secondary linkage and get things lined up better.

I'm not sure (because I can't see everything) if you could use the Edelbrock adapter 1481 to move everything out where it would be hooked up better AND it would be pulling straighter.

Second, I would recommend a dual return spring for the throttle return, the last thing you want is a wide open throttle situation that you can't control.
 
Bad Sport said:
I'm not crazy about a couple of things there. First, I think you need to get the throttle cable out from behind the secondary linkage and get things lined up better.

I'm not sure (because I can't see everything) if you could use the Edelbrock adapter 1481 to move everything out where it would be hooked up better AND it would be pulling straighter.

Second, I would recommend a dual return spring for the throttle return, the last thing you want is a wide open throttle situation that you can't control.
Click to expand...

I think that is a very good call Sport, as it sure would simplify things and make the geometry of the linkage right.
It's totally possible that the bolt was through it to try and make up for messed up geometry.
 
TrailBeast said:
I think that is a very good call Sport, as it sure would simplify things and make the geometry of the linkage right.
It's totally possible that the bolt was through it to try and make up for messed up geometry.
Click to expand...

Could be, or it could be that the adjustable TPL rod is extended out as far as it can go making it impossible to get the pin to the rear of the slot.

And again, IF the 1481 would bolt on there it might just fix that issue as well.

Isn't there two different lengths on those TPL rods?
 
Bad Sport said:
Isn't there two different lengths on those TPL rods?
Click to expand...

I'm sure depending on different years and engines.
The one he has looks pretty good it's just hanging to the rear a lot.
(or likely forced there by that bolt through the slot.)

Betcha that thing bangs second at about 25-30 mph. :-)
If it doesn't right now it's going to work like crap with the bolt out of the slot.
Might need the internal pressure brought up after fixing everything wher it belongs.
 
Yeah, I think some minor re-working of that linkage set up is in order.

About 30 minutes and it would be 100%.

CR, are ya still with us, lol.
 
The parts house one town over has them in stock. It's always shifted hard so I guess now I know why.

The car also occasionally revs up when it shifts too. maybe by mellowing out the shifts, it'll help with that?
 
Corrupt_Reverend said:
The parts house one town over has them in stock. It's always shifted hard so I guess now I know why.

The car also occasionally revs up when it shifts too. maybe by mellowing out the shifts, it'll help with that?
Click to expand...

Usually lowering the line pressure (which taking out that bolt and nut will do) will make things like that worse.
We call that a flaired shift (engine rpm's flare up between shifts)
Could it be a bit low on fluid and sucking air?
Does it happen to be on corners that it does it?
Checking the fluid running in neutral?
 
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