Knock & Car Stability Problems

[infurno]

I thought it would be better to start a new thread rather then resurrect a longer, old thread.

The problem:

1. Car feels unstable. When going over bumps at speed, it starts to swerve. Front end drifts side to side, and feels like I have no control. This is pretty alarming, especially on a wet road...
   
2. I'm getting knocking sounds in the car all coming from the front end. Its worse over bumps, but its also there lightly at highway speeds on smooth road. Its constant, always there, no mater what speed, or how smooth of road. (good roads help reduce levels)
   
3. Squeaky, almost bird like sounds, as well as more alarming grinding on tight turns sometimes heard. Something is dieing, but fluids and levels remain ok. Maybe related, maybe not.
   
4. Bad vibrations, especially on poor roads. No breaks applied, just driving. I figure that this may be just because of the bad road, and the new, stiffer "sporty" suspension components... So, I accept it as it is, but sometimes it just does not feel right at all.

Here are the front components that have been replaced:

1. thrust arms
2. control arms
3. tie rods
4. center tie rod / center link
5. idler arm

Troubleshooting...

• With the car jacked up, I tug on the wheels and there is a bit of a knock sound. Almost like a bad ball joint, and thats what I thought it was. But when I removed the old center tie rod, it looked like it was in good shape. I replaced it anyway. Problem did not go away. With further inspection, the knocking appears to be coming from the gimble located onthe steering box connecting to the steering wheel column. I grabbed the gimble and tugged on it, and it did make a bit of a knock sound. However, i'm not convinced that this is the cause of all my problems. In fact, it may be normal. - I did tighten the bolt some more on the steering column inside the car.
  
• I'm left to think that it may be the front shocks, and their mounts. I know I need new ones, but... Thing is, the ride appears to be steady. I don't think its too bouncy, and both the front left and right appears to ride smooth and stable.
  
• I have not replaced the sway bar links, but they are firmly attached, and look like they are in decent shape... But could this be it? I can replace them, but I just have a gut feeling it wont help at all.

I ordered new sway bar links. May as well, the only other thing left to do is the shocks, and thats something I would like to avoid if at all possible. (just because of the more complex and possible life threatening work)

I'm at a total loss. Have already started looking for a new car, but I would rather keep this one... I'm going to schedule an appointment at a shop to see if they can find the problem for me.

Meanwhile, anybody have any ideas?

[whiskychaser]

When you replaced the front suspension components, did you torque the bottom arm with the wheels on the ground and a couple of people sitting in the car? It will handle like a tea trolley if you didnt

[Tiger]

It should be the sway bar links for the hard bang sound when you hit a bump. It is very possible for the constant knocking sound on smooth road. I know on the Toyota Avalon, that was the case... smooth road and whoa nelly! bunch of knocking! They have similar type of sway bar link as the BMW but shorter.