Seal Plate Damage – Excessive Wear of Bearings
If the thrust or journal bearings become excessively worn, then they can cause damage to the seal plates like in the example pictured here.
When bearings become worn, this allows the rotor assembly to float on its axis. In turn, this allows the back face of the compressor wheel (on the left of the picture) to rub against the face of the seal plate.
Over time, this begins to wear away at both surfaces, reducing the effectiveness, output and efficiency of the turbocharger. You can see in the image that the damage is mirrored on both parts.
If your turbo suffers this kind of wearing damage, the only way to bring your turbo back to full efficiency is to replace both the compressor wheel and the seal plate.