I am posting this as a public service for those that don't know it yet. It's been 8 months since I learned about and posted the cure for MT82 crappy shifting and grinding. This was on the advice of a Ford engineer who is an old friend of mine.

The cure is Ford part ADDITIVE - OIL - FRICTION MODIFIER Part # XL18
It is a tiny bottle less than 1 oz. of transmission additive. It is included in the factory fill for 2014 Mustangs. It really does make a huge difference.

The cost is about $23 list on FordParts.com. Then there's labor. Maybe you can get Ford to pay for it, I couldn't. I will remember that when I go to buy a new car a few years from now.

Make sure you shake it up well and/or mix it well with some transmission fluid as there's a lot of gelatinous glop in the bottom of the tiny bottle.

If you have a 2010-2013 MT-82 manual this is as good as it's gonna get.