Hi, New to the site, looks lke a great one. I have a 1997 F350 motorhome with a overdrive auto transmission. The trans. started shifting hard and the light started flashing on the overdrive control and I had no speedo. It even went into neutral, I guess, because I had no gears at all and then it came back to where I had gears. I unplugged it and I had all the gears but it shifts hard with no speedo and overdrive flashing.I replaced the rear end speed sensor and it fixed it, for a while and then it started doing it again. Could I have a bad sensor, could the fluid need changed or I have read that there is a sensor in the transmission also. Sorry this is so long just trying to give as much info as possible. Appreciate any help, going on vacation in the West Virginia mountains in a couple of weeks, hate to loose my tranny.