------Chuck,,,I havent only heard of problems, I had one and figured out why. The oil change shop talked me into doing the "exchange machine" on an old 1987 Pontiac wagon I bought for a winter beater. Immediatly after I left, I noticed a slight whine that wasnt there before. Car had 80,000 original miles, probably hadnt ever had the fluid changed, and functioned perfectly. Jan and I were taking a drive out west in the car and I didnt think the whine was a big problem, WRONG!!!
------We made it to Arizona before the trans expired and had to go to a "chain" for repair or replacement. Trans turned out to be full of metal from as small as dust to as big as a pencil eraser. The "tech" immediatly stated that some of the pieces looked like chunks of torque-converter fins. Long story short the pressure involved in the fluid change had actually bent some or all of the torque-converter fins and initially caused the slight whine. As time went on the fins (now fatigued) failed and spread metal thruout the trans......POP...... Never again!!!
.......Bill S