The Ultra Shift works great. My notchy hard shifter is now like butter. Two key things to remember. 1) Fill to the proper level. Too much or too little will not work properly. 2) allow about 500 miles for full break-in of the
oil. You will feel a difference right away but it will keep getting better every time you drive your car. I know dozens of guys (all of us had the same issues with our Tremec) and every single one of them would use nothing else now other than Ultra Shift. It is not cheap but you get what you pay for. Anyone who says all oils are the same does not understand oils and the various ingredients and properties of each. I am NOT saying other oils are bad nor am I saying that Ultra Shift is the only good product. It simply seems to be the only good product for our trannies in the way that we use them for the purpose of smoother shifting. If you are unsure, call Cobra Valley directly. The owner can explain the properties of the
oil, why it works and how it was made, better than anyone here can. He can also share what testing was done.