I did a fluid change the other day. I used the same amount of fluid I used the last time which read fine on the dipstick so I was being stupid and assumed it would be alright this time. I put in the same amount and didn't bother checking the dipstick.

Wrong.

I got home after driving about 15 highway miles and checked the dipstick and I was over the top line by about a little less than the diameter of a valve stem cap. No idea why there's such a huge difference in the amount when I put in the same amount I did last time. I'm assuming more drained out last time, maybe from the torque converter.

Anyway I did some testing, I poured the fluid I got out into a can, marked the position then emptied it and put in enough water in quarts to measure how much I put in and marked the position and compared, there was a difference of between 1-2 cups, I must have filled the transmission about .35 of a quart extra, half a quart max.

I plan on trying to siphon the extra out but I'm wondering if I've done any permanent damage. I've already driven about 60 highway miles on it, little if any stop and go and I may have to drive another 30 highway miles on it before I can siphon it out. What am I looking at here? Blown seals? Although I don't understand how more fluid blows seals. Foamy ATF causing premature clutch disk wear? I haven't noticed anything particularly spectacular. No barfed out ATF all over the engine, no smoking, no leaking, no issues with the AT while driving (for now).

 

keep us informed as to what you find out..

 

is this on your 09 or 95 ???

 

I really think it's OK. Driving around corners would get the oil to slosh to one side or the other, so any given component inside the tranny has to be able to tolerate THAT.

In an engine, overfilling can lead to the crank journals whipping up the oil into a froth.