Problem is resolved.
First: Go to dealer to check what could be wrong when doing lubrication maintenance. The lubrication technician didn't find the problem(He should tell me more info).I was told by dealer service representative(she is professional) that wheel balance is needed.
Second: Doing wheel Balance (Costco), I was kindly informed by COSTCO technician team leader that inner side of my 2 front tire are almost worn out that he can not do 2 front tire balancing. Considering my driving feeling and all these words from dealer and COSTCO guy, I believe what Costco technician said should fit my situation. I decided to buy new all season tire from COSTCO. (Even though it looks like "expensive").
I replace 2 tires, and the steering shaking problem is gone, and I am driving comfortably. COSTCO tire technician worths trust.
Thanks all for kind advice.