I have a 96 explorer 4.0 with the 4r55e Tranny. I bought it with 118000 miles and today i service the transmission (drop the pan) and i found the pan full of metal shavings around the magnets and in the pan. the tranny it doesn't seem to have been servised again. right now i'm at 140000 miles. i add motocraft ATF because i didn't want to take any risk at this point switching to synthetic. do i have to worry about it.it doesn't give me any troubles right now. any advises are welcome.