Problems with Rebuild

[bogies87]

So I am in the process of putting my stock turbo back together after a rebuild. The rebuild is pretty straight forward. I sent my compressor shaft and had it balanced. Now I am trying to get the shaft put back in the center section. With the shaft seal in place and pushed into the center section, I put the cold wheel on and snug (and I mean ever so lightly) the turbo gets hard to turn. I have checked, checked and rechecked again and can not see anything out of place. Any body have ideas as to what could cause this??

 

[bogies87]

Just information for anybody that has run into this problem. I found the culprit, I disassembled the turbo completely again. When installing the thrust collar be sure it is put on the correct way. One side is dome shaped and the other is flat. The domed side goes toward the bearing, while the flat side goes toward the carbon seal side. Once this was discovered tightened down and spins freely.