Auto Transmission Shifting Issue Since 4bbl Upgrade

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MrFollmer

MrFollmer

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Johns Island, SC
Hey there A body Gurus!

I inherited a '65 Dart 270 Convertible from my grandfather who sadly passed away in 2016. He and I wrenched on this car for most of my childhood and it was a backyard build. I love the car and it is the reason I love cars to this day.

The car sat in my garage for about a year before I decided to do a minor upgrade. It has a '66 273 motor with a 2 bbl carb and ran very rough - was begging for fuel. So I upgraded to an Edlebrock Intake (part #2176) and matching Edelbrock 4 bbl carb (part #1406). I had a mechanic install these to ensure it was done correctly. Transmission is an automatic 904.

Now that all is installed, the transmission seems to shift at the wrong RPMs. I don't have a tach in the car so I can't give you those specs. 1st and 2nd gear seem ok, but 3rd revs high before shifting into gear. I also don't see a kick-down cable or linkage. Shifter is floor shift, aftermarket Hurst.

Would anyone have any ideas where I should start to solve this problem? Is it a tranny rebuild, is it a vacuum line in the wrong place? A setting on the shifter? Or perhaps the fact that it doesn't have any kickdown linkeage? I have to be missing something that's obvious.

My grandfather is probably rolling over in his grave at my struggles...I just want the car back on the road where she belongs! Thank you for any assistance you could provide.
 
We need pictures. There should be a kickdown rod on the throttle linkage to adjust.
 
The kick-down linkage probably needs adjustment.
Give it a couple turns (either way) and test drive

If the problem gets worse go the other way

Hard shift to late shift
Are the two issues you may get if not adjusted correctly
I just can't recall which direction corrects which issue.

I could quote the factory procedure but you probably do not have the linkage setup as the system has been modified.

It is quite possible it can't be adjusted as the 2-bbl linkage is different and the alignment may be off and causing problems of its own.


Alan
 
I will post photos later on today once I have the ability. I'm almost certain there's no linkage hooked up. Thank you.
 
You'll destroy the transmission if that "kickdown" linkage is not hooked up. That isn't all it does. It's more like a throttle position sensor too. Even if the 2-bbl linkage was somehow re-attached to the 4-bbl it probably can't/won't work right without the correct linkage. Read this article, and you'll have a good understanding:https://www.hotrod.com/articles/the-lowdown-on-stock-torqueflite-kick-down-linkage/
 
The 1st to 2nd shift is supposed to happen at 18 mph, and the 2nd to 3rd shift is supposed to be at 28 mph. That is just under normal driving conditions. The transmission won’t last long with no kickdown linkage. There was some for sale in the mechanical parts for sale section the other day, and it was 4 barrel linkage. There is a difference. Good luck.
 
Get a lokar kickdown cable kit and be done with it. Dont drive it again until you get a kickdown on it.
 
Many 2bbl to 4bbl conversions move the throttle hook up location forward. The kickdown, if not corrected, doesn't usually push far enough back to work properly. Edelbrock makes a little conversion piece the fits between the slotted end of the kickdown and to rod that lengthens the rod to make up for the difference. Its cheap, simple and looks right.

For sure let me echo what others have said - get this right before you drive the car or you WILL be into a rebuild! A small tach is cheap, easy insurance for your car
 
I'm going to guess that most of the existing linkage will work, except for the parts right at the carburetor itself. Might be worthwhile to call A&A Transmissions, maybe they can supply the right OEM parts. http://www.aandatrans.com/search.aspx?keyword=linkage
I only suggest this because the Lokar cable I had was somewhat problematic too. After a lot of trial and error, I really think that the correct factory setup works the best.
 
If there is no kickdown on it find a new mechanic. The KD (properly know as throttle valve or TV linkage) does much more than kick down the transmission. It controls internal transmission fluid pressure in relation to throttle setting. This affects shift points. At higher throttle settings the TV linkage sets the transmission fluid pressure higher to increase holding capacity of the clutches and bands.

Basically, at wide open throttle, the TV lever on the transmission should be pushed all the way back. At idle it should be free to return, unencumbered, all the way forward. It should start moving back slightly after throttle tip in, or just off of idle.

Without a TV linkage your transmission will be short lived.
 
Here is the Mopar carb linkage bracket you need for your 1406 Carb.

MoparBracket.jpg

Edelbrock Part Number: 1481
Get you going for starters, need to rework the 2 bbl kickdown linkage to work with the new 4 bbl.
 
If the transmission is already flaring going into high gear, the damage is done. The 3rd gear clutches are damaged. You can install the throttle pressure linkage, or convert to a cable and it may improve, but the damage is done. High gear will be weak from here on out.

That linkage does not just perform the kickdown feature. It also controls the transmission's throttle pressure. The more you press the gas pedal asking for more power, the more line pressure the transmission needs to see in order to hold the clutch packs together under acceleration and not slip.

Removing that linkage, or not having it adjusted correctly will burn the transmission up one forward gear at a time, starting with high gear, then second, the finally first. Your third gear clutches are already damaged. Even shifting manually does not solve the problem, contrary to what some people say. It must have the throttle pressure linkage or cable and it must be adjusted correctly for the transmission to work correctly.

Go ahead and either get a cable setup or the factory linkage setup and adjust it correctly. It will likely improve it, but I am afraid high gear is damaged beyond hope at this point.
 
RustyRatRod said:
If the transmission is already flaring going into high gear, the damage is done. The 3rd gear clutches are damaged. You can install the throttle pressure linkage, or convert to a cable and it may improve, but the damage is done. High gear will be weak from here on out.

That linkage does not just perform the kickdown feature. It also controls the transmission's throttle pressure. The more you press the gas pedal asking for more power, the more line pressure the transmission needs to see in order to hold the clutch packs together under acceleration and not slip.

Removing that linkage, or not having it adjusted correctly will burn the transmission up one forward gear at a time, starting with high gear, then second, the finally first. Your third gear clutches are already damaged. Even shifting manually does not solve the problem, contrary to what some people say. It must have the throttle pressure linkage or cable and it must be adjusted correctly for the transmission to work correctly.

Go ahead and either get a cable setup or the factory linkage setup and adjust it correctly. It will likely improve it, but I am afraid high gear is damaged beyond hope at this point.
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Good Explanation on what the "Kickdown" does and why it it's important.
 
If it's late shifting into 3rd the TP may already be high enough for whatever reason to not destroy the trans. (it could be tied back or something like that)
That's not to say it fine like it is though.
 
RustyRatRod said:
If the transmission is already flaring going into high gear, the damage is done. The 3rd gear clutches are damaged. You can install the throttle pressure linkage, or convert to a cable and it may improve, but the damage is done. High gear will be weak from here on out.

That linkage does not just perform the kickdown feature. It also controls the transmission's throttle pressure. The more you press the gas pedal asking for more power, the more line pressure the transmission needs to see in order to hold the clutch packs together under acceleration and not slip.

Removing that linkage, or not having it adjusted correctly will burn the transmission up one forward gear at a time, starting with high gear, then second, the finally first. Your third gear clutches are already damaged. Even shifting manually does not solve the problem, contrary to what some people say. It must have the throttle pressure linkage or cable and it must be adjusted correctly for the transmission to work correctly.

Go ahead and either get a cable setup or the factory linkage setup and adjust it correctly. It will likely improve it, but I am afraid high gear is damaged beyond hope at this point.
Click to expand...

Thank you to everyone that responded with expert suggestions and opinions. After much thought over the last 24 hours, I've decided to move forward with the following plan of action:

1. Order the Lokar kit (already did via Jegs)
2. Going to visit the local trans shop to inquire about a full rebuild of the A-904
3. Hope that the trans shop is knowledgeable enough to help me hook up the new Lokar kit correctly
4. Consider changing the shifter out - I don't like the aftermarket one my Pop installed. I'll seek the guidance of the trans shop on this one.

Even if the trans doesn't need a rebuild, the Dart hasn't been on the road more than 400 miles since we rebuilt it back in the early 90's. I feel way more comfortable starting fresh. The last thing I want on my mind while cruisin' with the family is when the transmission is going to fail on me...nothing worse than worrying while driving. 'Ef that.

Lastly, I suppose I need to upload some photos. Will do that today, hopefully. Thank you again! And if anyone is in the Charleston, SC area, please let me know. Can always use someone to bounce ideas off of and to meet up at local shows. And Semper Fi to all my Marines out there!
 
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MrFollmer said:
Thank you to everyone that responded with expert suggestions and opinions. After much thought over the last 24 hours, I've decided to move forward with the following plan of action:

1. Fire my mechanic who said I could simply downshift to do the same as the KD linkage
2. Order the Lokar kit (already did via Jegs)
3. Going to visit the local trans shop to inquire about a full rebuild of the A-904
4. Hope that the trans shop is knowledgeable enough to help me hook up the new Lokar kit correctly
5. Consider changing the shifter out - I don't like the aftermarket one my Pop installed. I'll seek the guidance of the trans shop on this one.

Even if the trans doesn't need a rebuild, the Dart hasn't been on the road more than 400 miles since we rebuilt it back in the early 90's. I feel way more comfortable starting fresh. The last thing I want on my mind while cruisin' with the family is when the transmission is going to fail on me...nothing worse than worrying while driving. 'Ef that.

Lastly, I suppose I need to upload some photos. Will do that today, hopefully. Thank you again! And if anyone is in the Charleston, SC area, please let me know. Can always use someone to bounce ideas off of and to meet up at local shows. And Semper Fi to all my Marines out there!
Click to expand...

I think @goldfish65 is in Charleston. I tagged him so maybe he will chime in. He is a super nice guy you will definitely want to meet.
 
MrFollmer said:
Thank you to everyone that responded with expert suggestions and opinions. After much thought over the last 24 hours, I've decided to move forward with the following plan of action:

1. Fire my mechanic who said I could simply downshift to do the same as the KD linkage
2. Order the Lokar kit (already did via Jegs)
3. Going to visit the local trans shop to inquire about a full rebuild of the A-904
4. Hope that the trans shop is knowledgeable enough to help me hook up the new Lokar kit correctly
5. Consider changing the shifter out - I don't like the aftermarket one my Pop installed. I'll seek the guidance of the trans shop on this one......
Click to expand...
You also will need the Lokar throttle cable kit. You have to have it if you want the Lokar kickdown cable. And with the Lokar kits you won't need the Edelbrock 1481 lever/bracketmentioned earlier. I hope you can find someone who can follow instructions, or has already installed the 2 Lokar kits. It is time consuming and there is quite a bit of trial & error to get it to work right. I'd seek out a member in your area that has installed it and have him/her help you install it. It is certainly something any amateur mechanic can do. If I wasn't 900 miles away I'd help you with it!
 
69_340_GTS said:
You also will need the Lokar throttle cable kit. You have to have it if you want the Lokar kickdown cable. And with the Lokar kits you won't need the Edelbrock 1481 lever/bracketmentioned earlier. I hope you can find someone who can follow instructions, or has already installed the 2 Lokar kits. It is time consuming and there is quite a bit of trial & error to get it to work right. I'd seek out a member in your area that has installed it and have him/her help you install it. It is certainly something any amateur mechanic can do. If I wasn't 900 miles away I'd help you with it!
Click to expand...

That is a fantastic idea. He's in South Carolina. Maybe we have a member in that area who could help? I'm in Georgia and would be glad to do it but it's a little bit of a haul.
 
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69_340_GTS said:
You also will need the Lokar throttle cable kit. You have to have it if you want the Lokar kickdown cable. And with the Lokar kits you won't need the Edelbrock 1481 lever/bracketmentioned earlier. I hope you can find someone who can follow instructions, or has already installed the 2 Lokar kits. It is time consuming and there is quite a bit of trial & error to get it to work right. I'd seek out a member in your area that has installed it and have him/her help you install it. It is certainly something any amateur mechanic can do. If I wasn't 900 miles away I'd help you with it!
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Thank you! I did buy the throttle cable too. And the entire list of parts mentioned in the instructions for the 904 provided by Lokar. If I can’t get it right - the plane tickets are on me! Charleston is an amazing vaca spot!
 
Mr Follmer
When you install the Lokar kits, replace the "L" bracket that goes on the transmission end of the cable, with something more robust, like good thick angle iron. When I installed mine, I found that the flimsy bracket that came with it kept bending, throwing it out of adjustment. I made a thick angle iron "L" bracket, and have not had any problems since.
Also make sure you have the spring, that holds the TV in the forward posistion installed to hold the TV forward. The cable pulls against this spring when giving the engine more gas peddle. Take all the slack out of the wire in the cable housing. Have someone under the car (safely) to hold the lever forward, and then tighten the cable anchor screw, on the carb end. After its installed, and adjusted, check it once in a while as the wire can stretch, then you might have to readajust it., as I said.
Hope this helps Dave
 
There used to be a Mopar club in that area called Low Country Mopars. Lots of good, nice people used to be in that club. Maybe look them up online and see if the club still exists.
 
JDMopar said:
There used to be a Mopar club in that area called Low Country Mopars. Lots of good, nice people used to be in that club. Maybe look them up online and see if the club still exists.
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For sure. There’s a SoCar Mopar Club that exists but I’ll have to look for the LowCountry one. SoCar is mostly new Challengers and Chargers. There’s a few classics there, but not many. Just very excited to get the ‘65 back on the road!
 
barracudadave67 said:
Mr Follmer
When you install the Lokar kits, replace the "L" bracket that goes on the transmission end of the cable, with something more robust, like good thick angle iron. When I installed mine, I found that the flimsy bracket that came with it kept bending, throwing it out of adjustment. I made a thick angle iron "L" bracket, and have not had any problems since.
Also make sure you have the spring, that holds the TV in the forward posistion installed to hold the TV forward. The cable pulls against this spring when giving the engine more gas peddle. Take all the slack out of the wire in the cable housing. Have someone under the car (safely) to hold the lever forward, and then tighten the cable anchor screw, on the carb end. After its installed, and adjusted, check it once in a while as the wire can stretch, then you might have to readajust it., as I said.
Hope this helps Dave
Click to expand...
I have to disagree Dave. A spring to hold the trannie lever forward is not recommended by the experts (Read the A&A article I posted earlier). It is not necessary. I had the Lokar kit on my 340/727 '69 Dart and it worked fine once I got it all adjusted properly (and that is a real trial & error task). And I never had an issue with Lokar's trannie cable bracket either. Perhaps in the last several years Lokar improved the kit? No idea how our Lokar experience could be so different.

Now, I will say that I like the stock parts better, mostly because once it's adjusted properly it stays adjusted. I found/procured all the correct stock pieces and did a bunch of research, and got the stock setup to work. If I hadn't been able to, I would have put the Lokar setup back on. I just prefer the stock setup, which works O.K. with a Holley, with Holley's bracket, an Edelbrock 7176 Performer intake, with no spacers under the carb. If anyone has a higher intake, or puts any kind of spacer under the carb, the stock lever/rod setup will never work, and you will have to go to a Lokar cable.
 
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