[Cobra20646]

The only way you could posssibly over fill it would be to remove the top, fill the case and then replace the top.
Since most of us install the transmission dry, and fill it up using the "fill" orifice, it becomes almost impossible to over fill it.
If you can follow me here, the fill hole is located on the right hand side of the case. It has a plug with a square head that you unscrew and remove. Fill it till it starts to run out of the hole and then replace the plug. If you think it overfilled, remove the plug, let the excess drain out, and then replace the plug.
- Jim -