727 Not Shifting Properly Now

[Moparmarty50]

I bought my 66 Coronet (383 4 bbl) 6 years ago and it had the transmission rebuilt before I got it. A Cheetah valve body with standard shift pattern had also been installed. I took it for a ride today and kicked it down after making a turn and it shifted from second to first and then back to second. RPMs were climbing when I accidently pulled the console shifter back into first. It shifted back into first so I quickly shifted up to second and let the engine rev some more. I shifted into Drive but it stayed in second.

I stopped and started some light footed driving again but first gear went to a high RPM (over 2500) before it shifted to second. This is not normal in 6 years of ownership. While driving in second I could not get it to shift into drive even manually moving the shifter back and forth. I stopped and shut off the car and restarted it only to find no change.

I know nothing of automatics. I believe my actions today caused something to cause the transmission to act like this. I am asking for advice on what I should look at underneath next chance I have. I only have regular hand tools and no specialized transmission tools. Any and all advice greatly appreciated. Thanks.

 

[pnora]

If it has kickdown linkage make sure its free and returning.

 

[Dave6T4]

Does it still back up?

 

[Moparmarty50]

Yes reverse works as it should, neutral and park also correct.

 

[Outlawd]

It don't sound too serious, has to be kickdown linkage or cable which ever you have must have slipped out of adjustment or something physically is not letting it return properly. Check adjustments make sure nothing is lose and exercise throttle linkage by hand with engine off, have somebody watching the lever on the tranny to see if anything is interfering with the movement.

 

[Dave6T4]

If your car still starts in Neutral and Park, your problem is not slipped linkage. What happened to cause this problem sounds kind of violent, making sudden big changes in internal fluid pressure. I wonder if it cracked a fluid channel in the valve body? This is rare, but I have seen it 2 or 3 times over the years of rebuilding TorqueFlights. Maybe @dvw can chime in on this? He has lots of experience, and understands the hydraulics better than I do.
You could drain the fluid and drop the oil pan to see if there is any shrapnel in the pan. If your pan does not have a drain plug (most do not) this can be a messy exercise, because the only way to drain it is by loosening all the pan bolts and let fluid leak out at pan gasket. It helps to have a large diameter oil drain pan to catch the fluid.

 

[Rebelrouser]

I bought my 66 Coronet (383 4 bbl) 6 years ago and it had the transmission rebuilt before I got it. A Cheetah valve body with standard shift pattern had also been installed. I took it for a ride today and kicked it down after making a turn and it shifted from second to first and then back to second. RPMs were climbing when I accidently pulled the console shifter back into first. It shifted back into first so I quickly shifted up to second and let the engine rev some more. I shifted into Drive but it stayed in second.

I stopped and started some light footed driving again but first gear went to a high RPM (over 2500) before it shifted to second. This is not normal in 6 years of ownership. While driving in second I could not get it to shift into drive even manually moving the shifter back and forth. I stopped and shut off the car and restarted it only to find no change.

I know nothing of automatics. I believe my actions today caused something to cause the transmission to act like this. I am asking for advice on what I should look at underneath next chance I have. I only have regular hand tools and no specialized transmission tools. Any and all advice greatly appreciated. Thanks.

View attachment 1603861

Governor pressure has to overcome throttle pressure for a shift to occur. Look at the throttle linkage first and make sure it is not sticking, at idle the throttle lever on the transmission should be all the way forward and at wide open throttle it should be just against its stop. When the transmission does not **** when you let off of the gas if the governor is sticking it will not pull the engine down when you let off, it will neutral. To check governor, you need a pressure gauge, pressure should equal speed on the speedometer will top at about 60psi. drive it on a rack or stands. Sometimes you can blow air in the test port and rattle the governor to clear and dirt and get it working again.

 

[Moparmarty50]

Thanks for all the responses! I will check operation of kickdown linkage later today if not tomorrow and report back. Keeping fingers crossed.

 

[Moparmarty50]

Good News! Got car out and made first check at kickdodn linkage. Went to move it and found it stuck wide open. No real binding so I lightly lubed friction points topside. The return spring probably too light also so I crimped a little more on the straight part of the spring to give a little more pull. Probably will replace it. Took car out and it drove as it should.
Many thanks to all who responded. All responses probably could have caused this situation. It helped me by more knowledgable people giving their opinion. I was a little bummed when this happened because the drive on Sunday was to make sure all was good. I plan on selling it soon for more room and getting my 69 Roadrunner (4 speed) painted. Thanks Again.

 

[pnora]

Good News! Got car out and made first check at kickdodn linkage. Went to move it and found it stuck wide open. No real binding so I lightly lubed friction points topside. The return spring probably too light also so I crimped a little more on the straight part of the spring to give a little more pull. Probably will replace it. Took car out and it drove as it should.
Many thanks to all who responded. All responses probably could have caused this situation. It helped me by more knowledgable people giving their opinion. I was a little bummed when this happened because the drive on Sunday was to make sure all was good. I plan on selling it soon for more room and getting my 69 Roadrunner (4 speed) painted. Thanks Again.

I said it first. [lol]

 

[12icer]

I found out the hard way that a torqueflite will break the clutch pack spring, push it through the lock ring and lock the clutch engaged.

Glad you had the easy fix.


Nice car BTW!!!!