This is from the turbo I pulled out of a truck from the company I work for...

I wonder what would have caused this.

 

Could one vane have failed and a piece broke off; then that piece hit the other vanes causing them to break, also? Is it possible a "foreign object" entered into the area resulting in this damage? If yes, I imagine you would have found it. It will be interesting to see what you determine. Roy

 

if you look at the vgt fins you will the damage will match the size and shape of the fins. turbo got stuck and unison ring overtravled.

 

When I took apart my turbo to clean it, I found that the unison ring would allow the VGT veins to come into contact with the fins right where you're damage is, which like Cheezit said may be your culprit.

 

That seems like a very stupid design....

Is there a way to modify the turbo so that it will not do this?

 

not a common issue

 

 

Yeah it's a very stupid design. I would expect to get fired for such a thing however I bet the reason it is like these is because this ring/vein/ect parts can fit into many of their models of turbos (saves money). You could modify the slot in the ring to disallow that interference it wouldn't take but a mm or so in the slot itself but you'd have to weld the slot and then mill it to spec. If I had one in hand I could do run the numbers and figure it out for you if you really want to do it. I doubt it would trip any codes or cause a problem with the VGT sensor because the sensor isn't going to (under normal conditions) force the veins into an interference condition. In short, if everything is working right you shouldn't need to mod the ring but if yours had been modded, it prob would have saved your company a $grand$.