I think many Trac's have had folks who did not have the manual work on them, and all sorts of things go wrong..
Get the manual up and print it out. You must make sure you understand that there are two nuts you adjust for belt tension, and the lower one is hard to get at, till you make a special wrench that is...
They must be moved the same amount each time as you adjust tension of the belt.
In mine someone had loosened the wrong nut to adjust the belt tension. They loosened one of the spring tensioner packs, adjusted one time only at the factory.... The machine would not turn to the left as this move on some one's part broke the factory staking that should have held it. As time went on it loosened itself and I lost the ability to turn left...
Take time to understand the manual and how this thing really works. A wrong move here changing the belt could effect how "on center" the steering is. In other words, straight ahead will no longer be exactly in the center of the range of motion of your steering wheel. Or worse a broken ST25 in the steering if the belt is too tight. What belt did you get, the Goodyear? Wash it before you install in soap and hot water to get the parting compound off, and make sure everything on the sheeves are greese and oil free... Belt dust will not stick to variator sheeves and parts afer the washing of the belt. Better traction that way....
Take some time now, and reap the rewards this Feb at The Big Powder Horn..
Regards, Kirk