727 issues after carb swap

[Stegs]

I just swapped out my eddy performer 600 for a holley 4160 750

A friend of mine did all the new fuel lines and tuned the carb for me

Car runs great, but now i have a trans issue that i didnt have before with the eddy


It seems now my cars shift points have all been raised to a higher rpm. 1st to 2nd will about break your neck, 2nd to 3rd is really high in the rpm range


I remember when i had my shift kit put in, the trans guy adjusted everything for me and it was perfect, but now with the holley it seems everything is in the higher RPM range?


I hooked up the linkage just like it came off the eddy, i bought the adaptor (part number 20-7 i think)

There is no binding in the throttle linkage, its way better now that its pulling straight.....


Wondering if anybody knows whats going on? maybe a easy fix?

[cdr]

shorten the trans rod at the carb, try about 3 turns in & drive it & see how it is.

[Stegs]

shorten the trans rod at the carb, try about 3 turns in & drive it & see how it is.

not to sound dumb, but "trans rod"?

3 turns? clockwise or counter?

ill see what google turns up

and peek into my service manual tonight

[ODZKing]

I know which he refers to, how to adjust I always let people who know exactly what they are doing adjust it ... but having said that here is the illustration
#2, you should be able to remove the cap and turn it either way to make it longer or shorter.  The guys here can explain which way, but that is it.

[Stegs]

I know which he refers to, how to adjust I always let people who know exactly what they are doing adjust it ... but having said that here is the illustration
#2, you should be able to remove the cap and turn it either way to make it longer or shorter.  The guys here can explain which way, but that is it.

Thanks for this diagram!

I may just have my trans shop do it....i dont want to burn up my 727

[cdr]

Clock wise, but if you are unsure go to your trans shop.

[Stegs]

Clock wise, but if you are unsure go to your trans shop.

i called a trans shop, he is convinced that the linkage is installed wrong, but the adaptor went on just like it showed....all the linkage lined up fine...hooked up fine

ill look it over, but thats what he said.............

[ODZKing]

If it was fine before and only the carb changed then it is most likely correct. I'd try a place that knows older Mopars.
My   ... try what CDR says. Do one full turn at a time, drive it, if it feels wrong, do one more.  Just don't drive it all day if you feel it is wrong. And if several turns one way doesn't feel right, try the other way.  Always be sure to note what you did so you can go back to where you were.  My camera phone has come in quite handy for things like this.
I won't kid you, there is an art to this and I admire guys who can adjust these things. But unless your carb guy took everything apart and reassembled ... I doubt it is wrong.
But as I said my  

[303 Mopar]

I may just have my trans shop do it....i dont want to burn up my 727

The Mopar linkage is one of the poorest designed, most convoluted mess ever IMHO.

I made a slight adjustment on by bar because it was hitting the firewall before WOT, and it messed up the shift points similar to yours.  1st to 2nd was around 30 mph and 2nd to 3rd was over 55 mph.  I tried to adjust the linkage and finally took it to a very experienced guy at a trans shop.  $100 and a couple hours and he had it dialed in perfect!

Another alternative is to buy a LOKAR cable set up and trash all of the linkage.  The cable set up is very easy to adjust your shift points.

[John_Kunkel]

The design is fine and the function is positive and reliable. Many problems arise from incorrect/mismatched pieces and people who don't understand the principle of operation.

The Lokar is absolutely the worst choice to replace linkage, poor design and even worse instructions.

[ODZKing]

The design is fine and the function is positive and reliable. Many problems arise from incorrect/mismatched pieces and people who don't understand the principle of operation.

The Lokar is absolutely the worst choice to replace linkage, poor design and even worse instructions.

I would have to agree, once it is adjusted correct and set ... it's set!
I had a friend that had a shift cable that broke on the way to Carlisle. Luckily we weren't far but he had to turn around.
Once we got it in drive, he had to leave it there and not turn the car off until he got home.
That was fun ... I'm just sayin.

[Stegs]

im going to look into this, im just wondering on my drive home if something rattled loose.....i mean it was really nice before, all i did was a carb swap so my guess is that something, somewhere may have rattled loose or came apart


The guy who did my fuel lines and tuned the carb test drove and he said it was good when he did it, which we both came to a conclusion that something rattled loose


Ill investigate and report back

[BSB67]

Step 1: Buy a service manual.  Step 2: Adjust the KD linkage (or TP what ever you want to call it).

This is easy enough, you don't even have to do it in this order.

Russ' rule #97,  If it runs fine and you touch it and it no longer runs fine, the problem is what you touched, always.

[Stegs]

ok checked over everything last night

The linkage on the carb is free, no binding, the holley adaptor is on correct


What i did find, the "rod" the goes down to the trans along the firewall will not go all the way down when you push it

i went underneath the car and nothing is interfering with it...so it has to be something in the trans?


When i grab the linkage on the side of my carb and rev it by hand, will wont go back more than halfway. I checked to make sure the gas pedal was clear or any obstruction and it was


That rod will not go all the way down like it use to


I did go up and down the street last night, just to see. It went into drive fine, shifted thru all 3 gears fine. went about a mile and everything was fine

Turned around, shifted manually into 1st gear and thats when trouble started. It wouldnt shift out of first, I had no 2nd gear or 3rd (even in D)

But 30 seconds earlier when i pulled it out of my barn, i put in in D and it shifted fine...


I think its a trans issue, I checked and rechecked everything with the carb, and thats all i touched.

Im not too worried as the car is in storage now, Ill deal with it in the spring unless its something easy to fix now

These old cars are expensive and you keep working on them, and you dont even get to drive them 

[b5blue]

  You changed the amount of travel at the carb. The distance from "0" throttle to "Full" throttle in movement is not the same between carb A and carb B. So now the ratio of movement at the transmission is too short. You may need a shorter K.D. lever or move the rod attaching hole inwards at the 727. You may get by with a short extension or find you at the very limit of adjusting the rod longer depending on linkage set used.
  I went through this when I swapped from 6BBL to CH4B and Proform 750 recently. The components need to match the ratio of travel not just at the limits but under part throttle conditions so get back to your tranny guy to sort this out. 

[Stegs]

  You changed the amount of travel at the carb. The distance from "0" throttle to "Full" throttle in movement is not the same between carb A and carb B. So now the ratio of movement at the transmission is too short. You may need a shorter K.D. lever or move the rod attaching hole inwards at the 727. You may get by with a short extension or find you at the very limit of adjusting the rod longer depending on linkage set used.
  I went through this when I swapped from 6BBL to CH4B and Proform 750 recently. The components need to match the ratio of travel not just at the limits but under part throttle conditions so get back to your tranny guy to sort this out. 

ok so it sounds like a fairly simple solution, and there there is nothing wrong with the 727 itself, just a adjustment needed

Ill see if he can work on yet this year, the weather is going to turn so i may have to wait until spring...which isnt bad either

Thanks for the info!!

[John_Kunkel]

Is the linkage spring (#13 in the pic above) intact and pulling the linkage forward so that the rear of the slot in the top rod (#12) is resting firmly against the rear of the stud?

[Stegs]

Is the linkage spring (#13 in the pic above) intact and pulling the linkage forward so that the rear of the slot in the top rod (#12) is resting firmly against the rear of the stud?

yea it look just like the diagram

I messed around with it again last night, i cant figure out where i went wrong.....it might be something with the trans, but how can a carb swap change that. It has to be something i did with the carb, but it was a straight forward install with the holley especially using the 20-7 adaptor

When i get home from work today i mess with it some more. ill print this diagram and go step by step, i must be overlooking something really straight forward


If you push #1 straight back towards the firewall, it will go back maybe a inch or so, and then stop, like its hitting something. If i sit in my car and push the pedal to the floor there is no binding or rough spots...its really nice and smooth.

something with the throttle controlling the trans

[68charger440]

As they say " A picture is worth a thousand words".  Take a couple of pics of your setup and someone may spot your problem more quickly than through Q and A. A pic at rest, mid throttle and then at full throttle may be of use also.

[John_Kunkel]

If you push #1 straight back towards the firewall, it will go back maybe a inch or so, and then stop, like its hitting something. If i sit in my car and push the pedal to the floor there is no binding or rough spots...its really nice and smooth.

To be sure WOT in the car is WOT under the hood, have somebody sit in the car and floor the throttle, from under the hood push back on the carb lever...if the throttle lever will move back more you need to readjust the throttle cable. If the carb lever is actually at WOT then push back on #1...it shouldn't mover more than 1/4" or so.

[Stegs]

i will try to get a pic, but i think its  a trans issue

I have no 2nd and 3rd gear now

The rod going down will not move down move that a inch or so

i went under the car, the rod coming down and over to the trans is free....nothing binding, but when i tried to move it under the car it was stuck or something....


the diagram that was sent in a earlier post, i printed it off and went step by step thru it.....mine looks just like the diagram

Ill see if i can read thru the service manual and figure it out, otherwise ill take it to the trans shop this spring

[John_Kunkel]

When in doubt, temporarily remove the linkage at the trans lever and allow the lever to come full forward. If it still won't upshift the problem is in the trans.

[68charger440]

Make sure your lower bell crank (7) is pivoted forward and not backward.  If it is pivoted backward it can prevent the proper range of motion. Pull the cotter pin on (7) and see if (11) moves smoothly.  If it does then I would lean toward it being a linkage setup problem. Then reconnect the cotter pin keeping the (2) to (7) rod pivoted forward and see if you now have full linkage movement again. It will take 5 minutes to double check that under the car as that can get flopped backwards when swapping the carbs out.

[Stegs]

Make sure your lower bell crank (7) is pivoted forward and not backward.  If it is pivoted backward it can prevent the proper range of motion. Pull the cotter pin on (7) and see if (11) moves smoothly.  If it does then I would lean toward it being a linkage setup problem. Then reconnect the cotter pin keeping the (2) to (7) rod pivoted forward and see if you now have full linkage movement again. It will take 5 minutes to double check that under the car as that can get flopped backwards when swapping the carbs out.

Ok i give it a look

[ODZKing]

But as mentioned by someone previously, if it was fine before and nothing was taken completely apart. And the only thing that was done was the install of the carb, it has to be up top.
IF you want to know if it's the trans, replace the carb with the old one. If it's fine, the issue is just an adjustment as stated.

[68charger440]

But as mentioned by someone previously, if it was fine before and nothing was taken completely apart. And the only thing that was done was the install of the carb, it has to be up top.
IF you want to know if it's the trans, replace the carb with the old one. If it's fine, the issue is just an adjustment as stated.

Once you take the springs off to replace the carb it can allow the rod and lower bellcrank to move freely into the improper position.  Then when you put the new carb on and reattach the springs it holds the rod in the incorrect position.

[Stegs]

But as mentioned by someone previously, if it was fine before and nothing was taken completely apart. And the only thing that was done was the install of the carb, it has to be up top.
IF you want to know if it's the trans, replace the carb with the old one. If it's fine, the issue is just an adjustment as stated.

Once you take the springs off to replace the carb it can allow the rod and lower bellcrank to move freely into the improper position.  Then when you put the new carb on and reattach the springs it holds the rod in the incorrect position.

its got me thinking maybe thats what happened maybe

Ill look when i get home, i printed off 2 of those diagrams....hopefully thats it!

My trans was 100% perfect before the carb went on....has to be something im overlooking