4r70w transmission problems

[Kiddmustang]

2000 mustang GT auto Transmission . Wasn’t moving in Drive or Reverse. So I change the filter and the ATF. Added 6qt of MERCON V. Now the transmission is engaging but is rolling forward in Drive and Neutral and even Reverse the car is launching forward and backs in all gears almost like I press gas but I didn’t. I don’t know if I red to check the shift linkage I did losing the bolt some to remove the pan because the car was stuck on uneven ground when I check the ATF the dip stick was completely dry even tho I added 6qt. yes I did check it on uneven grounds because the car is stuck right there. I just need help I don’t knew if the transmission need another 2qt of ATF or it’s the shift linkage or something else .

 

[gkomo]

I have zero experience with new edge mustangs so take this with a grain of salt, but Google/Copilot came up with this?

Did only 6qts come out when you drained it? Does that transmission need a friction modifier?

 

[apple99Mustangdude]

You may read my other post about my experience, similar to what I think the poster above is referring to about the friction modifier - I made the mistake of having my auto trans FLUSHED at 180,000 miles or so, and it started slipping badly on the hwy, I had to pull over wait a few, and restart the engine, then was able to drive home ok. I hopped on forums and discovered my mistake, you don't FLUSH a trans at high mileage (and some say never) you just do the old drain and fill as in the old days, I was told to drain enough fluid to add a bottle of Lucas trans fix, the proper one for my year and make of car - it worked! Currently I have 249,000 miles on my car, and it almost always shifts perfect, only a good "bump" when on a road trip, heavily loaded, accelerating and decelerating in hilly mountainous driving - I do know the trans is worn, I expect to rebuild it in a year or two - and I am not hot rodding around, I may drive fast when caught up in traffic, but I only put the petal to the medal when I have to -