'66 C-Body Kickdown/Throttle Linkage Pops off/Disconnects at Upper Bell Crank When Start Accelerate/Shift Down

[C-440-300]

Not sure where to start...
'66 300 with a regular motorhome block, added headers and upgraded to Mopar's EI (blue box).
She's less than 20K miles on rebuilt tranny with a shift kit. Runs great and peeps on both shifts when WOT.
Except, lately, the adjustable middle rod (vertical) pops off the top ball on the bell crank when I press anything over "Sunday Granny" mode.
I wn't say I've heard it all regarding adjusting the linkage. FSM or Jamie @ Dead Dodge Garage, either way.
I have not checked any of the pressures, but will coming up on the weekend(s).
You don't really notice the difference until you want to shift down.
There is no binding. The lines are all in their places. The throttle pressure lever is stock. The spring is strong.
There are no leaks in that area; front seal a bit.
It feels at the foot that something is stopping me when off the line if I want to show off and the pedal goes about an inch, then "easy" to the floor.
I get off it fast, thinking I dn't want to gas it with no pressure.
All this in less than 50 feet.
Any guesses? Advice? Thanks, C-Mates!

 

[CBODY67]

Check the roundness of the ball-stud. Otherwise known as "wear". Nothing in the transmission should cause more stress up there than just the linkage moving itself.

Also check the rod end for a firm engagement with the ball-stud, too. Maybe some good wheel bearing grease might heop it move easier?

CBODY67

 

[Dads300]

Yeah, either the ball is loose or worn, the socket is worn, or the spring clip that keeps it together is bent or worn. If all of the parts are moving freely in the same plane, that’s really all it can be. If there is an issue, you can build a new link with spherical rod ends from the hardware store and it’ll last another 50 years.
Travis..

 

[fury fan]

I think the prior responses are on the right track, but I have 2 questions that might be related.
Was your car originally a 383, and what KD linkage did you use?

 

[Dads300]

I just realized that you have a 440. If this car was a 383, you may need to lengthen that vertical rod to keep the linkage in its normal range of motion. I would have someone work the throttle while you watch the linkage to see what is happening. It may be very evident why it’s popping off.
Travis..

 

[CBODY67]

If the rod only pops off at the end of the travel, might also inspect the other linkage pivot points (usually a round rod in a round hole) for wear, too. If, say, you can get the throttle past "fast idle" and it stays on at larger throttle positions, then you might get one of the throttle rod extensions from Edelbrock. Screws onto the rod at the carb end, lengthening it for when a 2bbl is replaced with a 4bbl (needing a longer rod). That might provide enough extra assembled length to get the ball socket/stud past the point where it becomes disengaged from the ball stud. Doesn't cost much and easy to install. In the Edelbrock online catalog.

Just some thoughts,
CBODY67

 

[Sixpactogo]

I just adjusted my kick-down linkage on my 65 Sport Fury a couple weeks ago. The service manual tells you exactly how to do it. If yours is set up properly and the rod falls off of the ball, you probably need a different rod. I have a couple of them. I believe they were the same for 383 and 440.
Maybe all you need is the threaded connector shown in this pic.

 

[C-440-300]

Check the roundness of the ball-stud. Otherwise known as "wear". Nothing in the transmission should cause more stress up there than just the linkage moving itself.

Also check the rod end for a firm engagement with the ball-stud, too. Maybe some good wheel bearing grease might heop it move easier?

CBODY67

If the rod only pops off at the end of the travel, might also inspect the other linkage pivot points (usually a round rod in a round hole) for wear, too. If, say, you can get the throttle past "fast idle" and it stays on at larger throttle positions, then you might get one of the throttle rod extensions from Edelbrock. Screws onto the rod at the carb end, lengthening it for when a 2bbl is replaced with a 4bbl (needing a longer rod). That might provide enough extra assembled length to get the ball socket/stud past the point where it becomes disengaged from the ball stud. Doesn't cost much and easy to install. In the Edelbrock online catalog.

Just some thoughts,
CBODY67

First off, always appreciate replies on this site.

You might have a thought there on the roundness and grease I know it's not shiny ball round. Hmm.
Also, I didn't think about the linkage not being long enough. I could actually lengthen it by turning it more counterclockwise to test.
Thanks on the Edlelbrock part. Just FYI, it is an original 440 car, the intake is the Edlelbrock Performer RPM, no real mods except added headers, simple Edelbrock 1406 (600 CFM), and shift kit.

 

[C-440-300]

Yeah, either the ball is loose or worn, the socket is worn, or the spring clip that keeps it together is bent or worn. If all of the parts are moving freely in the same plane, that’s really all it can be. If there is an issue, you can build a new link with spherical rod ends from the hardware store and it’ll last another 50 years.
Travis..

I just realized that you have a 440. If this car was a 383, you may need to lengthen that vertical rod to keep the linkage in its normal range of motion. I would have someone work the throttle while you watch the linkage to see what is happening. It may be very evident why it’s popping off.
Travis..

Thank you, Travis. Yes, it was always a 440. But, I have seen other situations where we take for granted about what we have. So, I won't bet my paycheck that something isn't original as I thought. I am the 4th owner, but, really, the second to work on it, keeping it alive. The other two were passing it along/storing/hoping to use later after grandma passed on.
Getting an eye on it while in motion is a must. I can mount a video and light on the booster or something and take it for a ride? I'll keep all of you posted. Cheers!

 

[C-440-300]

I think the prior responses are on the right track, but I have 2 questions that might be related.
Was your car originally a 383, and what KD linkage did you use?

Yes. 440 since inception in late '65, actually. The KD is what as far as I know/can detect with my eyes while looking at the FSM, the three piece with ball on top, spring clips on the bell crank to carb (with Edelbrock Mopar adapter, spring clip on bottom bell crank to ball at tranny lever. Thank you(!) for asking and I will report back to ya'll!

 

[C-440-300]

I just adjusted my kick-down linkage on my 65 Sport Fury a couple weeks ago. The service manual tells you exactly how to do it. If yours is set up properly and the rod falls off of the ball, you probably need a different rod. I have a couple of them. I believe they were the same for 383 and 440.
Maybe all you need is the threaded connector shown in this pic.

View attachment 667003

View attachment 667004

Hello, SixPac, Very kind of you to take pics. I will do the same. I was going to ask/wonder if the same parts for 383 and 440. I think I can get access to the Parts Catalog. I saw it online (Allpar?). I have to admit as I get older, too, that I want to believe our babies will last forever as they were born. Reality ain't so, I know. If I am indeed in need, I will let you know. I could try to "secure" somehow so that while motion OK, they can't separate? Actually, I never thought as all of you have replied about these separating. My initial was that the tranny was resisting and pushing the "weakest link" (pun not intended) just passed the point of failure. I'm sort of excited to learn, anyway it goes. Thank you, again. More, later.

 

[Sixpactogo]

Hello, SixPac, Very kind of you to take pics. I will do the same. I was going to ask/wonder if the same parts for 383 and 440. I think I can get access to the Parts Catalog. I saw it online (Allpar?). I have to admit as I get older, too, that I want to believe our babies will last forever as they were born. Reality ain't so, I know. If I am indeed in need, I will let you know. I could try to "secure" somehow so that while motion OK, they can't separate? Actually, I never thought as all of you have replied about these separating. My initial was that the tranny was resisting and pushing the "weakest link" (pun not intended) just passed the point of failure. I'm sort of excited to learn, anyway it goes. Thank you, again. More, later.

Hello, SixPac, Very kind of you to take pics. I will do the same. I was going to ask/wonder if the same parts for 383 and 440. I think I can get access to the Parts Catalog. I saw it online (Allpar?). I have to admit as I get older, too, that I want to believe our babies will last forever as they were born. Reality ain't so, I know. If I am indeed in need, I will let you know. I could try to "secure" somehow so that while motion OK, they can't separate? Actually, I never thought as all of you have replied about these separating. My initial was that the tranny was resisting and pushing the "weakest link" (pun not intended) just passed the point of failure. I'm sort of excited to learn, anyway it goes. Thank you, again. More, later.

The parts book will help with part numbers but it is the FSM (factory service manual) that tells you how to adjust the kick-down linkage. I'm betting you have the correct parts but maybe that clip that holds the socket onto the ball has opened up and no longer doing it's job.

 

[fury fan]

Good that you originally had a 440, as I believe the intermediate/vertical rod is shorter for the 383, and too short to adjust up to the 440 length. (but that is based on tinkering on a small sample size)

For my anecdotal experience, see here:
No avoiding it; I MUST get NEW Linkage Hardware Now Right? Kickdown Not Kicking.

 

[Clover]

Good that you originally had a 440, as I believe the intermediate/vertical rod is shorter for the 383, and too short to adjust up to the 440 length. (but that is based on tinkering on a small sample size)

For my anecdotal experience, see here:
No avoiding it; I MUST get NEW Linkage Hardware Now Right? Kickdown Not Kicking.

Yes, the vertical rod is longer for 440 vs 383. You can screw the 383 rod all the way to the limit and it will just barely work on a 440.

 

[493mike]

Don't drive the car until this is properly operating or clutch damage will occur!
Mike

 

[fury fan]

Yes, the vertical rod is longer for 440 vs 383. You can screw the 383 rod all the way to the limit and it will just barely work on a 440.

Thanks for confirming that. As I was re-reading that old post I had made, looking at it with fresh eyes, I realized I was not 100% sure I had a 383 rod in there in the first place.
Which would've made my conclusion invalid.