So twice this has happened, and the first time it was much more violent. So far I have replace the upper control arm "inner" bushings on the right side but today it happened again, but not as bad, and it may just be because I wasn't going nearly as fast. The power steering fluid is full. I replaced my rack with a used one about 6 months ago. It was in good condition but the mechanic I had helping me complained about how he couldn't do it, wanted to buy it, so a week later I walk in and within an hour or so I get the last line hooked up. What do you know while I'm under the car he dumps brake fluid in it and fills it up. It's either the left side bushings, upper ball joints, outer tie rods or cv joints.. because recently and most likely unrelated, when I make a U-Turn or very sharp turn i hear a ticking like something is in a bind. I've had the car for seven years and it's lowered but I've never had any issues. A couple months ago I found that my struts weren't even hand tight as well.
What you are describing is called bump steer.
This is caused by a toe change when the suspension travels vertically.
Common Causes include
- Incorrect tie rod height or lenght
- steering rack that is not mounted parallel to the datum plane.
- bent steering parts
- structural damage to the vehicle
I'd start by checking the mounting of the steering rack since it was recently replaced. Make sure it's level and make sure the tie rod ends are not bent.