My "new" 96 SW2 auto with 71K was fine for first 10 days, then began missing shifts, locking in 2nd or 3rd and shifting hard, especially into reverse. Also hangs on downshifts when braking. Problem is intermittent. Seller claimed that he just had a rebuilt valve body and 2 new solenoids installed and a trans flush. Fluid was a little low, topped it off. There might be a leak, see fluid around valve body cover. Problem showed up after driving in rain. Any clues or direction would be appreciated.