I'm having the same problem with my 95 Jimmy 4x4. I had the trans serviced (dropped pan and had new filter and fluid) just over a year ago, but I've only turned over 3k miles. It seems that it only happens on my way home (1 mile 25% grade up hill at one point). Either way is only 5 miles. I put a cup undernieth the tube just so i stop making a mess out of the driveway, but i want in on when someone finds out whats goin on.