Transmission Leak BAD!!!

92 explorer with about 140,000. All in all runs fine but about 2 months ago it began leaking fluid from the trans. It dumped everything out of the bellhousing. Now the truck is driven on almost a daily basis but only for short trips. If I drive more than about 10-15 miles and allow everything to get up to full operating temperature it will leak A LOT. I suspect the front seal. Basing this on as the transmission warms up, the seals become softer and the fluid thinner. If anyone has any other possibilities before I take the trans out I would appreciate them. It is a 4x4. Thanks