Sorry if this issue has been discussed somewhere before. This post if for a relative that owns a 2010 Altima Coupe 2.5 S. When starting to accelerate, after about 20 mph the transmission makes a strange clunking type sound, as if its changing gears roughly. Its doesnt jerk the car around but im wondering if it is a TSB issue, or a recall or simply the transmission fluid changed. It only has 19k miles. Any comments will be greatly appreciated. Thanks..