Due to "popular" demand:

Attached is the TSB regarding converting to Mercon V. I strongly recommend not believing anything which others might say. I did, and wasted money (luckily no further damage).

There are at least 2 other members here who did the same, and suffered such large leakage of the rear seal (it eventually disintegrates as mix of Mercon and MerconV is becoming agressive to its material), it will cost you a lot.

I followed the TSB to the point, and did it all again a few hundred miles later. Total cost was around $175 for the first time, around $69 for the second time.

I'm not an engineer, but if you want to know the chemical issues arising when mixing old Mercon and MerconV, use the search function. I posted all the TSB's and articels from Ford and MerconV manufacturers.

Now I don't have any shuttering anymore, no slipping, and so far no noticable leakage.

Greetings!