Did my transmission fluid replacement a few days ago. When dropped old fluid, counted about 7.5 quarts or so.
When filled, I could only put in about 6 quarts (including about one glass of fluid wasted during filling).
So I could not fill the 8.5 quarts or so to fill. Drive around and opened fill plug again adding about 1.4 quarts.
However to do that, I had the car on, and ghe durametric was showing tempted about 55 C.
So I wonder if there is a way to overfill the transmission on this car., and if so, what are the potential issues one could face fown the road if overfilled.
My feeling is I did not overfill (put in what I dropoed) but wanted to get your opinions and these two answers. Thank you.

 

I would check from scratch. Hook up to the durametric, run it up to 40 C while shifting through the gears. When it gets to 40 C take out the drain plug. Either let any extra drain or fill till it spills over. That way you know for sure.

 

But can one overfill?
If yes, what are the risks?

 

If you follow the proper filling procedure, you will not over fill. That is why I think you should start from scratch. I do not know the risks of overfilling. I would imagine it would depend on how much.

 

I understand but I opened this thread about potential issues if you do overfill, and if you can overfill at all. I know what the procedure is and can easily follow it. I would like to know about the questions I'm asking though.
Anyone have insight into my questions?

 

There is a vent tube on the transmisson. I don't think your going to get a definitive answer Ciaka. I would take an educated guess that overfilling may cause some blown seals and/or erratic behavour.

The reason that the procedure wants the trans at a specific temp during filling is:

A. There is an inline thermostat going to the fluid cooler. This thermostat needs to be open to ensure a purge of all air in the lines and cooler. As soon as you start the engine after a fluid fill, the pump.is going to suck some air and send it right thru those lines.
B. We all know fluid expands with temp. Having a median temp.
upon filling/ topping off likely ensures that "A" is completed, and the fluid is neither grossly expanded or contracted at this median temp, ensuring a range of fullness up and down the temp scale.

If you were to check the fluid while extremely cold and all air purged, it would probably show low. On the contrary, if you were to check the fluid blazing hot with all air purged, it would probably show overfilled.

 

This part is concerning. This should be 40 C for refilling (unless you opened the tranny cooler lines; then 90 C). I have just had to drain and refill my tranny about 4 times in the last 2 months.

 

My gauge was the amount of atf that came out. So after drain, I wanted to ensure to put in same amount. Using the procedure (car atf pan at 40C), I could only get in just under 6 quarts (about 2 quarts less than what came out). Having full service records for car from dealer, any fluid in was done by mechanic there.
So what you say is making sure what comes out is same as what goes in is not that correct?
The 55C was the temp I had after the car was standing, turned on and idling. With fill hole open, nothing was flowing out. I put in but less than 2 quarts before it started leaking. Knowing I now had same amount of fluid in as what came out, I closed the plug and finished up. Had I turned the car off, fluid would have started leaking out more, and I eilould have even less than what was there before change.
Advice would be great again but I thought my train of thought was logical. Thanks again.

Renaissance man, I wish I one day had in my sig 700hp or more. You da man.