I know in my instructions that came with mine it says that if the chute hits the blades it's because you have flattened out the chute by bumping it into something and it is now pushed in toward the blades. It's shipped with the center bowed outward a bit so they won't hit the blades and you just need to put a slight bend back into the center again.
Also if you go to their website there is a page that talks about the motors and what happens to them and a fix so you can try and get the motor working again. It's not a gear striping problem at all and that when you want to place the chute at an angle always start from the bottom and go up slightly. That is alot less stressful on the motors than trying to stop it on the way down.
Coral Lawn Care
JD 797 Z-Trak 72" Deck
John Deere G-15 WB
Echo PAS-260 Power Heads
Echo Trimmers / Blowers / Edgers