Projects 64 galaxie trans slipping - ran fine when put away in dec

hello all!

was FINALLY a decent day on sat so i took the 1964 galaxie out for a (short) drive. it was a short one because even after 15 minutes the transmission would slip into neutral whenever i gave the car any throttle. The car has its original 390 and auto transmission (c6 maybe i'm honestly not good with the transmission ID) 3 speed cruise o matic on the column. No matter what transmission selector, the problem persisted. If i was even with the gas the car was fine but as soon as i added some foot, the trans shifted to neutral, then I'd have to let it catch up so to speak and it would go back into gear.

the car has been dormant for a few months but i have started it and let it idle and even a couple shirt rides this winter when the temps were above 20 degrees. always starts great and the engine still runs very strong.

can anyone point me to where to begin investigating?

kickdown linkage?
old trans fluid (i checked it after running it for 20 minutes with car off and the level was up to the F mark, but i did notice a small leak at the tran rear seal towards the end of last year)
the trans was recently overhauled (less than 1k miles ago by a shop near me to the tune of $600.)

The car ran and shifted fine last year when I put her away, this just started randomly?

thanks for any help
- jason

 

You need to check the ****** will the car is running at idle in park.

 

and check all vacuum lines

 

awesome guys thank you very much. will check those things tonight.

thanks again!
- jason

 

If a place locally rebuilt it within the past year, i'd give them a call. Its not like you put 10K miles on it in the past year, shouldn't be leaking if it was just rebuilt.

 

Definitely sounds like a low fluid condition, as Saltflats stated, these cruise-o-matics should e checked with engine running, in idle, or you will get an erroneous reading.

---John

 

The Cruise-O-Matic has a dipstick tube that extends down into the transmission to shield the dip stick from splashed oil so you can get a correct reading. Some installers make the mistake of leaving the tube out until after the transmission is installed. Then it is impossible to get it in so they cut part of it off. The splashed oil shows that the level is higher than it actually is. If the tube has been cut, the only way to get close to an accurate dipstick reading is to have the stick out, wiped clean and ready to insert and have someone shut the engine off and quickly insert the stick and remove it.

 

now that is a very informative bit of knowledge!

 

thanks all. i checked it with the car runing and it was def low. about 1/2 on the stick so i filled it slowly while checking. took about 1/2 quart. went for a quick drive (20 mins each way) and it was better but not good. came back checked it again and level was still at F mark while idling in park. Went for another 35 min drive and again its better but not good. I could add more fluid but I dont want to go bonkers with it and possibly overfill it.

I will try Engine-man's suggestion but not sure if anyone will be around to help out. Given that there was some improvement (its not slipping nearly as much or with as much ease as it did before), would it be safe to add another 1/4 or 1/2 quart?

- jason