Ford Explorer Sport 1996 transmission problem. Only reverse works

My Ford Explorer Sport 1996, 141,000k does not go forward but can reverse. The o/d light turned on before the problem. What do you think the problem may be and how much do you think it will cost me to fix? Hopefully this can be fixed without having to install a new transmission.

Well, unfortunately every one I’ve ever seen like that had to have the transmission removed from the vehicle and either rebuilt or replaced. Last One I did like that had a bad sun gear. Reverse works backwards from the other gears, so sometimes broken bearings can let it go backwards, but not forwards. Those are VERY weak automatic transmissions, and the OD light is used to warn you that the transmission computer has a trouble code stored in it. You might just have it scanned to see what the code is, but as I said, all the ones I’ve ever seen like that needed expensive work. But, you never know, the transmission trouble code may be for something that can be done without having to remove the transmission (like valve body work which can be done by just removing the tranny pan instead.) If you need to remove the transmission, I would advise using an already rebuilt tranny from a rebuilding factory rather than fixing yours, as it is more cost effective in most cases.