I am wondering what assembly instructions did you use? (In fact was it a KKK turbo or a Garrett turbo?)
On the larger Garrett (Air Research) turbos that used to go on the Detroit Diesel engines (T10A40 turbo) the process was to heat the compressor wheel, line it up with the marks torque it to specs; after cooled back to room temperature it was torque again to specs. After which you used a dial indicator to check the axial and end play of the shaft. Before running the turbo you are supposed to squirt clean oil into the oil inlet to pre-lube it.
Garrett turbos have 2 full floating bearings, the KKK I do not know about.

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84 300D, 82 Volvo 244Gl Diesel