My transmission is getting harder to shift into ANY gear. It started as an intermitant thing last year. This past March I put Amsoil in the transmission and the problem got better but did not resolve itself. The warmer/hotter the days gets the harder it is to shift into ANY gear. If above 95 degrees outside and I have been on the road for at least 30 minutes, when I get into traffic, alot of stop and go then I have to force it into gear. When it is cool it shift ok but not easy, but I can feel that when it goes into gear it kinda clicks into place. I was thinking possibly several things, #1 Need to add some friction modifier, or #2 possibly synchro problem. It has done this with Syntorq and Amsoil, but not as bad with amsoil. Any transmission guru's have any clues? 
