I just bought a 1994 F-150 xCab - 4x4 - w/302 Auto with 40,300 Original Miles (83-year-old-man) and sometimes, not all the time the tranny will slip (at least I think) and then down shift when not nessecary. It was serviced when I bought it (fluid and filter). I run clean fuel and just changed the fuel filter on Sunday -so that's why I think its the tranny. My timing (motor)was just set back to 10 last Friday as well.
Anyone have a clue. Thanks Fella's - Tree Sling'r.