Car is making a clunking sound whenever it drives.

Try a new four-wheel drive actuator $150 on line. You can tell that this is the problem when you turn left or right and the wheels tighten up. This fix is on you-tube under chevy trailblazer 4wheel drive actuator replacement!

We went through 4 actuators before finding an oem one on Amazon.com. Started getting symptoms of traction control kicking in when first taking off on a cold start (service stability track error). You will also not be able to take tight turns and hear your tires squeal if on smooth pavement. I had a bad right front wheel bearing. It was causing the wheels to run at different speeds, kicking on the traction control. I believe the bearing had been bad or going bad the entire time causing the actuators to fail quickly. The mechanic used a scanner to check the wheel speeds, and properly diagnosing the problem after a year of constant repairs. The dealership stated they constantly have problems with this part, but could never narrow it down to why. This was fixed by an independent shop.