a general rule of thumb for turbocharging is that the oil return line should be at least 4-5 times larger than the feed line. also, make sure the tap into the oil pan is above the oil level or it will have a hard time draining. these are just a few things that lead to pre-mature CHRA failure. as long as the turbo still spins freely with your finger, and none of the fins on the wheels are damaged, just buy the rebuild kit and get it rebalanced after you fix those oil routing problems.