Hey guys! This is my first post on here, and I am having some problems with the infamous TR3650. I just purchased a good used Mach 1 from my local Ford Dealership. I have had it about a month now. The other day driving home I started getting a grind going into third gear. In the morning when I woke up and started for work, it was colder out, about 45 or so and it had went away, but it seems as I drove it more and it got up to normal operating temp in the tranny the problem presented itself once again. I took it and had the Tranny flushed and refilled thinking the fluid might be getting crappy. Still no improvement. I have read many bad posts about the 3650, and "gear-grinds"when it is cold... but never warm. My only guess is at colder temps the viscosity of my tranny fluid along with the pressure is greater and it runs better like that, when it heats up it thins out. Any thoughts on this? Possible fixes that have worked for someone with a similar problem? Different Fluid..... (I keep hearing RP works good) any/everything will be greatly appreciated! I am not sure if my syncro in third is going out cause it works fine when cold, but not when warmed up. If it was I would think I would be feeling it regardless of temp. Thanks!!:SNSign: