1955 Cadillac transmission questions

[ThomasBorchers]

Hello,

I have some questions regarding the 1955 Cadillac Hydramatic transmission. The shifting is a little bit rough when I depress the acceleration pedal just a bit to pick up speed. When I depress the pedal more, the shifting is smooth. Is this normal ? And : How to check the automatic oil level ? The shop manual says, that the engine has to run 2 minutes or so in “N”. The level at the dip stick should be at mark “full”. But : The shop manual says nothing about if the fluid should be warm, hot or can be cold. I replaced the fluid and filled up with cold transmission to level “full”. Now I am thinking if it could be, that it is now overfilled when the fluid is really hot after or trip of 100 miles and the fluid starts to foam and that this the reason is why the shifting is hard as described above.

Could someone help me please ?

Kind regards

Tom

[Guest imported_washburn]

Thomas,

You might want to post this at the Cadillac LaSalle site:

Cadillaclasalleclub.org

john washburn

[Jim Cannon]

Your transmission fluid level is too high. That is why it is foaming. Remove a pint or two and check it again.

You must check the fluid level hot. That means driving the car at least 30 km before checking the level. It must be done with the engine running, on level ground, in N (or P, if your car has it) and hot.

People ask me "What is hot?" When you remove the dipstick and grip the metal part that was down in the oil, it should be hot enough to be painful on your fingers. That is hot. Then the fluid level should be not over the full mark. Different dip sticks have different marks, so you go by what it says in the shop manual. When it is hot it must be between the limits they give in the book. The difference between Low and High marks on a transmission dip stick (unlike engine oil) is a small volume (usually only a pint).

Some books also give a procedure to check the level with cold fluid. Again, you need to read your book. It is common for a full transmission cold to be just on the tip of the dip stick, no higher than that, with engine running. But checking cold is not the recommended way to do it. Shops that work on these cars all the time know where to put the fluid level cold, from experience. The reliable way to do it is to check when hot.