What you are saying is based on the color of the grease

Update:14-06-2019
Summary:

In addition, the tight fit you said, the clearance is s […]

In addition, the tight fit you said, the clearance is small, resulting in discoloration of the oil. This reasoning should be like this: tight fit, small (remaining) clearance, increased bearing load area, and heat, resulting in oil denaturation, resulting in a change in grease color. And you said the running circle,

First, there may be problems with the cooperation of your bearing chamber.

Second, the internal clearance is too small and the friction is large, resulting in running circles. The latter possibility cannot be achieved by adjusting the fit. The worse you get, the worse.

Also, what you are saying is based on the color of the grease to determine whether the situation is normal. This judgment is very difficult. Different greases have different internal additives, different operating conditions, and different temperature ranges. It is impossible to have a uniform standard. Even with the same grease, the recipe may vary slightly depending on the batch being played. Please do not use this color change as a basis for unreliable.