The only way to mess it up is if the crankshaft, water pump sprockets are crooked or if the tensioner tab is not in the slot. As long as it didn't move when you tighten the tensioner nut, it's correct.i had the pointer in between the notchs. After the car was ran i looked and the pointer was way past the notches foward. I also thought i heard the belt whine on my test drive. But its not now. Should i tear it back down and check it? I turned the motor over twice and reajusted it because it was off. Just dont want it to break my belt.