If the fluid is over full it would be more likely to leak out the vent then it would be to come out the seal. The fluid just splashes around in there. They should be using the special tool seal installer that the new seal sits in and has shaft on it so you can hammer the new seal in without damage. Here is axle seal itself installation.
1. Clean seal bore in housing.
2. Apply a light bead of Loctite(R) 515 Gasket Eliminator Sealant (P/N 21005993) or equivalent on the diameter of the seal that presses into case bore.
NOTICE: Prior to using seal installer SA9113T, inspect tool for any nicks or burrs that may damage seal lip.
3. Install axle seal using SA9113T. Place seal on tool and insert into transaxle. Make sure to keep seal lined up with bore during installation. (Right side shown, left side similar.)
NOTICE: Use caution not to damage seal while installing axle into transaxle.
4. Install axle seal protector tool SA91112T inside seal.
5. Install axle into transaxle.
6. After shaft splines clear the seal but before snapping axle into place, remove seal protector tool.
7. Push axle all the way into the transaxle.
Tuesday, January 18th, 2011 AT 9:03 PM