Hey guys, I have a 2001 f250 with the 7.3. Its a 4x4 with the super cab. We bought it a month or so back and the tranny shifted pretty good but as of recently its been shifting pretty rough. Its not slipping or anything, just kind of clunking into gear pretty hard. Checked the fluid levels after i had gotten it warm and they were at the right level. i did notice that the transmission fluid was awful dirty, it didnt smell burnt but it was quite dirty. Im thinking about changing it out, but i have read tons of different things to change and ways to do this. I know im supposed to use Mercon tranny fluid, but have heard lots of things such as whether to change the filter out or not, whether to flush the fluid or just exchange, that kind of thing. Any help would be much appreciated! Thanks guys!

 

You should change it and use MERCON V, not MERCON fluid. MERCON has been discontinued, though you will still find fluids that say they are for use in transmissions that require MERCON. They are not MERCON fluids.

Here is how I recommend you do it: Click Here