I changed my oil Sunday and now it shifts like crap. I took out Regular motor oil that was what was recommended for it and put in Red Line MT-90 75W90 GL-4. It is HARDER to shift! I haven't driven it far at all. 5 miles tops inside the city. I noticed it after about 2 miles. It is mostly only first and second gear. I put this AX15 in back in June and haven't had any problems with it at all. I have done about 5,000 miles on it. I put in cheap oil because I knew I was going to be changing it after a few months to the Redline I just put in it. 90% of the hours are in the woods with it so I know it is a tough and solid transmission. As soon as I changed it it just feels more like metal on metal instead of a smooth shift lubricated real well. Did I do something wrong? I did a lot of research on what oil was best and this one came up the most for this transmission.