727 Doesn't want to stay in 3rd gear

[gradedcatfood]

I have a freshly rebuilt 727 behind my 440 and I'm having an issue where the car doesn't like to cruise or stay in 3rd gear. I am also using a Lokar kickdown cable with a Holley 750 double pumper.

While in third gear if I lift my foot off the throttle and slow down past 30-35 mph my trans will shift into 2nd gear. The same will happen if I'm making a slight turn at 45+ mph. The same will also happen if while I'm cruising and I give it too much gas (I'm not talking about flooring it, just a small but firm increase in pressure on the pedal).

I have tried several times adjusting my kickdown cable in different positions thinking that its an adjustment issue but I don't believe it is. I have moved that darn thing so many times, the issue doesn't seem to change. While the car is off and a helper floors the pedal, I then pull tight the kickdown cable tight and set it there (I have also tried some looser positions as well).

The car shifts great from 1st to 2nd, but sometimes does have a tough time getting into 3rd. It will sit on the rev limiter (5500 RPM) trying to get into 3rd gear so I have to let off the throttle a bit to get into 3rd. I don't know if that is related to above issue but thought I would mention it.

Anyone have any ideas on whats going on? Thank you in advance for your thoughts...

 

[Tooljunkie]

Fluid level crossed my mind, but if its freshly rebuilt, there may be a chance a seal got cut in assembly. Talk to the builder.

 

[gradedcatfood]

Fluid level crossed my mind, but if its freshly rebuilt, there may be a chance a seal got cut in assembly. Talk to the builder.

Wow, I feel kinda stupid. The tranny fluid always read full (Netruel while running) but I thought I'd give a shot and add .5QT. and almost all my problems went away... I have an aftermarket dipstick, so it seems like the cause has been low fluid all along....

Thank you!