your supposed to check ATF when hot... in park. 

also, a rise in ATF level when hot can indicate differential fluid (gear oil) leaking out of the diff. into the automatic part, mixing with the ATF and making the level go up..

chris 

Just to clarify,the ATF registers about 1.5" above the full mark on the stick when hot or cold. Also. when you change the ATF, how do you know what level to fill it, because the fluid is cold when you put it in.