So I have a T25 from a 300zx. I took it apart today to clock it (oil drain was on top). The compressor came off no problem, I then undid the bolts holding the middle of the turbo to the rear, and then with some love taps was able to get it out. The turbo before this rotated quite freely. I turned it around, put it back in, and tightened it down. I notice that when I get to really tightening down those bolts, the turbine becomes harder to move (not seized, and no grinding noise, but just not as smooth). If I loosen the bolts up a bit, it gets better.

What am I doing wrong? It seems like it's such a tight fit that it can't be off center. Am I just worrying about this for nothing? I realize the ball bearing turbos spin much easier then these older guys. Maybe i'm just crazy...

 

My T25 spun the same with the housings on or off...no difference. Make sure that backing plate behind the turbine wheel isn't getting ****-eyed or something. Also make damn sure you're tightening the bolts down evenly; a little bit at a time in a criss-cross pattern.

 

Thanks! I think it was mostly me second guessing how easy it moved before and after. I took it apart again just to make sure and went evenly over each bolt when tightening it down.