i am rebuilding my stock turbo, i have a small rubber o ring that came with the kit and i dont know where it goes. i did not take one off while disassembling it. where does it go? the shaft has 2 grooves on it near the turbine wheel. the first one was full of carbon, the second ( closest to the wheel) was where the metal seal was. is the first groove for the rubber seal? i cant see it as the heat would kill it. maybe it was killed and then filled up with carbon. the turbo has 130,000 miles on it. thanks for the info.