The patient is a 1993 US spec cruiser with 150000 miles on the original auto tranny. The tranny has had regular fluid changes with synthetic mobil 1 ATF and it is full. Fluid color is raspberry red and it does not smell burned. No towing. The tranny is slipping on upshifts. The revs will increase by about 500 to a 1000 then the next gear will engage adbruptly. Driven very mildly, it seems to shift fine, but it may just not be noticable on a light throttle. It is plainly noticable merging on a freeway at a good pace. My wife said she noticed this a couple weeks ago on a trip. She said it felt like it was in neutral --it would rev, but no power. I just noticed yesterday, after picking it up from the shop where the valve gasket was replaced along with the front brake pads. This sounds expensive. Any help will be much appreciated. Thanks!