I have a 98 GTX limited and it doesn't come with a carbon seal, it has a carrier bearing, some concept just different method. You will know it is a carrier bearing if you see grease fittings when you take the cover off at the rear of the motor. There is a small chance you have a carbon seal if someone replaced the original carrier bearing with one, it does happen. Here is a pic of the bearing.
In the picture you can see the zerk fitting pointing straight up and you, that is the carrier bearing, Goldish round piece by the clamp