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

[fury fan]

Does the linkage popoff coincide with the trans shifting, or motion of the KD linkage?
Does this trans have PTK (part-throttle kickdown)? Is the trans (or valve body) a 71-newer? (do you need FT to get a 3-2 downshift?)
Can it pop off when doing upshifts, or when downshifts, or both?
Either by manual shifting or automatic?
Can you get it to pop by moving the accelerator while in Park? In Drive with foot on the brakes?

If we can separate trans shifting from linkage motion maybe there's a clue there.

I doubt the fluid is a factor, unless it has a heavier viscosity when cold, enough to make the throttle valve more resistant to movement when cold. But that's truly a corner-of-the-box issue.

 

[C-440-300]

Hi, fury fan, The popoff (PO) is part throttle and is not during shift, but just under load, like off the stop sign, or super accelerating to pass.
The tranny has a Transgo shift kit when I bought it 19 years ago. This issue just started happening about 6 months?
I could not honestly tell if the valve body is newer or not. I would think so. Later, I could find time to drop it all and check for #s?
It never pops on downshifting. If I leave it in first or second, it never pops. Shifting up or down never POs.
While in park, I get no resistance and it revs up to limit.
The only thing my sorry memory can recollect is perhaps a top off qt of fluid? But, I did as I mentioned dropped pan/new filter and put in AMSOIL this summer.
You think I could have something sticking or blocked passage?
It's only when cold.
Thanks!
Cheers!

 

[Sixpactogo]

You still dealing with this?? I'm pretty sure your problem is in the snap on coupler that fits over the ball shown in my post #7. PM me your mailing address and I will send you one.