<VV> Droopy turbo?

[Grant Young]

I received a turbo for rebuild this week, but have not seen one this bad, so I thought I would float the information to see if I can give the owner some ideas to make his replacement last longer. This was a 1963/4 model ('63 carb side, 64 exhaust side). I had to press the (ruined) bearing out and there was evidence (gritty gray oily residue on the shaft) that some metal had stared to go (probably from a groove in the cartridge as there was a wear ridge on the turbine side of it). The most unusual thing was that the blades on the turbine appear to have "drooped" to where they were almost touching each other. There was a good 1/8" clearance between them (the small inner blades) and the turbine housing as a result. Can these things get that hot? There is no sign of contact between the blades and housing on either side (although the tip of one impeller blade was missing). I was initally thinking a lack of lubrication was the problem, but the rotating parts were free (although the longitudinal movement was excessive). It was not "coked" but there was excessive loose carbon on the outside of the heat shield. The carbon seal was not worn excessively, frozen, or cracked, and the internal sealing O-ring was still pliable. Any ideas on what killed it? Thanks,
Grant