My transmission was destroyed because the spider gears in the rear end stripped out and got locked up. Not because of the tune, or because the transmission clutches wore out. It was all hard metal parts that were damaged. He said the clutches were actually still in good to fair shape. The damage that occurred to mine ALL resulted from the rear end. Was it my fault the rear end went out? Possibly, yes. I have a heavy foot and I've done my fair share of burn outs. But had the spider gears not fucked up like that, my transmission would not have been destroyed.