[crushu]

I had the opposite problem, on my LX470. I put the standard belt that was supplied on, and the tensioner was so relaxed, that when you reved it, the belt would touch the row above it, and tear chunks of the little V's away.
It was a 2618mm belt, I tried a 2615, and the same happened, then I tried a 2605, and it was a nightmare to get on, but it was possible only on the round edged idler pulley, not on the pulley's with the shoulder. Now it doesn't touch, and the slipping problem has gone too.