727 kickdown question

[104thLRSD]

Hello all.

I am pretty new to the forum and the first time I have ever posted anything. I had a question and figured this the best place to find an answer. I bought a 68 GTX over a year ago. I have no idea what the previous owners did to the car and have limited history. I have been doing a lot of things here and there to improve it while keeping it as close to stock as possible. This is my first Mopar muscle car and I have never previously owned anything with a 440 or a 727 transmission. Someone had installed a shift kit in the transmission. The car starts out in 2nd gear and shifts to 3rd flawlessly. 1st will engage if I manually shift into that gear. When I drive the car at highway speeds and crack the throttle it accelerates fine but does not downshift. Is that normal? I feel like it is not kicking down. All the linkage is in place. Is it out of adjustment? or is it not adjustable because of the shift kit?

 

[vance.dykes]

Hello all.

I am pretty new to the forum and the first time I have ever posted anything. I had a question and figured this the best place to find an answer. I bought a 68 GTX over a year ago. I have no idea what the previous owners did to the car and have limited history. I have been doing a lot of things here and there to improve it while keeping it as close to stock as possible. This is my first Mopar muscle car and I have never previously owned anything with a 440 or a 727 transmission. Someone had installed a shift kit in the transmission. The car starts out in 2nd gear and shifts to 3rd flawlessly. 1st will engage if I manually shift into that gear. When I drive the car at highway speeds and crack the throttle it accelerates fine but does not downshift. Is that normal? I feel like it is not kicking down. All the linkage is in place. Is it out of adjustment? or is it not adjustable because of the shift kit?

go to mymopar.com and down load the manual for the car the adjustments will be in thre

 

[Demonic]

The car starts out in 2nd gear

That's bad. Govenor pressure issue or maybe the valve body. It should start in first. The lack of kickdown at high speeds is not unusual for a 70 and earlier stock transmission. Do you have a large face 300 psi gauge and about 5' of high pressure hose with 1/8' mpt fittings? Pressure tests per the factory can tell you a lot.

 

[Fran Blacker]

Have you tried putting gear shift in different positions? Shift pattern could be different than stock.
Need pictures of your car before the barbarians come for you.

 

[104thLRSD]

Thank you I do have a pressure gauge. And I mis-spoke. It shifts from 1st to 3rd skipping 2nd.

 

[Demonic]

Oh. That makes a big difference. Most likely is the kickdown band needs adjustment. Tighten to 72 inch-pounds and back off two turns.

Nice looking GTX!

 

[104thLRSD]

Thanks Man. Much appreciated...

 

[Lefty71]

Reading through what you've posted there's an issue for sure. Tough to get (or give) a definative answer because the term 'shift kit' can mean so many potential modifications from so many potential manufacturers. I guess if it were me, I'd start with all adjustments as if it were factory, whilst noting the current settings in a log, and see what the results are. Also, maybe worthwhile if possible to question the previous owner on specific mods done. If all else fails, pull the pan and possibly the valve body and see if you can figure out whats been done and whos parts are in there. Nice looking car, BTW.

 

[Dipstick]

Hello all.
When I drive the car at highway speeds and crack the throttle it accelerates fine but does not downshift. Is that normal?

A '68 won't kickdown at part throttle, only when the throttle is floored. At highway speeds maybe not at all, depends on the speed.

 

[104thLRSD]

Thank you all for the replies and advice. I bought the car through a third party and the previous owner was zero help and wouldn't even entertain a phone call. (I didn't realize this until after I wrote the check) I have been trying to figure out everything by myself and correcting things along the way. When I first bought the car I took it to a local transmission shop that still works on older stuff. That is who told me a shift kit had been installed. Transmissions and rear differentials are above my skill level. I am gonna take all of your advice and make the adjustments to factory and go from there. I found a vin stamp on the transmission and am pretty sure it was from a 69 Polara.

 

[dvw]

If it absolutely has no 2nd gear. I would drop the pan. Hard to believe the KD band is loose enough to have no 2nd gear at all. If the band is worn that far, chances are its close to metal. It is possible the servo piston is cracked or the strut may have fallen out. These are accessible in the car. If you drop the valve body you can air check the KD servo. If everything is is intact loosen the band adjustment lock nut. Count how many flats of the adjuster it takes to snug the adjuster down. If it takes more than 3 1/2 -4 the band may be excessively worn. If the throttle pressure linkage has been incorrectly adjusted the band is the 1st to sustain damage.
Doug

 

[wyrmrider]

back to the valve body
locate a later valve body with part throttle kickdown
then build it with the Transgo reprogramming kit do level 2
this is a DIY
then swap after you find out what your big problem is
do have a gasket and filter and some ATF+4
the OEM oil for the early years is no longer available and ATF +4 is good stuffand much better anyway
does your converter have a drain?
cheers

 

[104thLRSD]

I can manually upshift and downshift into 2nd gear. It skips second if the car is in drive. Goes from 1st to 3rd. Doesn't seam to slip or shift hard.

 

[dvw]

If manual 2nd applies then the servo is able to clamp the band. I'd be looking for a stuck 1/2 shift valve.
Doug