1. When the shocks are new, they tend to be very stiff! The shocks are built for extra heavy duty service such as off-roading, so Lexus makes them really tight! I took my 2010 LX in to have the shocks inspected when I had about 10K miles and again at 20K. I finally drove the car with a senior tech sitting in the car with me and he told me that it takes these shocks some time to break in. By 30K miles or so, the car ran beautiful and continues to run beautifully smooth til today (I have 136K miles). 2. The sensors or the shocks could be defective causing them to behave not as designed. Definitely replace the oil as others suggested. Also, have a tech hook up a computer to your car and watch the 4 shock's behavior on the screen as they respond to the road. The range on the screen (if I remember correctly) is 1-15. Sport mode (stiff setting) should have the shocks working in the 1-5 range or so. Normal (medium) from about 5-10 or so. Comfort (soft) from about 11-15. I observed the screen as the tech drove my car and noticed two things. First, the shocks were operating in the correct range based on the comfort settings. Second, all 4 shocks operated at approximately the same range of numbers. Even though the car felt stiff to me at that time (in particularly the rear shocks, since the car had no weight in the back) But per the computer they were operating as designed.

 

About 38 at temp I believe. Tires are Michelins with 6/32" left and I have the 20" rims.