I have a 1989 4 cylinder 5-speed Toyoya Camry wagon with 290,000 miles. I took it in to a "Pit Stop" for a motor oil change which they did. They said that the transmission oil did not look good and recommended a change which I agreed to. They said that their computer called for 90W GL-5 oil in this car. I said that my Chilton's called for Dexron ATF in the manual transmission of this car. I thought that I might have been mistaken, so I agreed to the 90W GL-5 which they did. When I got home I double checked my Chilton's and it indeed called for Dexron ATF. My questions are 1) Will this harm the transmission if I leave the 90W GL-5 in? 2) Assuming the correct oil is ATF, why is ATF used in a manual transmission? Thanks.