In this image, you can see a seal plate with the tell-tale signs of corrosion damage. On a new, undamaged back plate, the surface would be smooth, but here, corrosion has caused the face of the seal to become pitted, worn and roughened.
This kind of problem is fairly common on turbochargers that are used in marine and industrial applications, where moisture gets into the turbo and begins to weaken and wear away at the materials.
Corrosion damage only gets worse over time, and reduces both the efficiency and output of the turbo, as air from the compressor and gas from the turbine leak out into the bearing housing.
At AET, our expert teams can repair minor corrosion damage, but in more serious cases, it may be necessary to replace the component with a new seal plate.
Excessive play in Bearings
Here, the seal plate has been damaged by excessive play in the journal bearings (also known as thrust bearings).
On the face of the plate, you can clearly see that the bore has been chewed and worn down by the bearings. On the rear of the plate, the bearings have also caused serious cracks to appear around the bore.
Damage like this allows oil to leak past the seal area and into the compressor side of the turbocharger. Apart from causing significant damage to the compressor, this will reduce the efficiency and effectiveness of the turbo, and quickly cause it to stop working at all.
Unfortunately, if your seal plate is damaged in this way, the only real solution is to replace the component and the bearings. Your turbo will also need to be fully cleaned to remove any oil.
Excessive wear on 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.