Problem with steering, steering wheel "locks" up
I'm having a strange problem which my mechanic and I have been unable to sort out despite considerable effort.
The problem is as follows:
When the car is stationary and the steering wheel gets turned to the right there is a point where it naturally has to stop, i.e. there is resistance and it can't be turned any further. This is perfectly normal.
However when the car is slowly driving forward you reach the same point and feel the resistance initially, but then it goes away and the steering wheel can be turned by another bit.
After doing this, it is difficult to turn it back to the left as there is quite some resistance and only after this resistance is overcome it can be turned back to the zero position. Also there is some knocking sound when overcoming the resistance.
Just to be clear on this:
- The problem only happens when the car is driving forward.
- It does not happen when the car is stationary or on a ramp.
- There is no play or wear in the components involved that we could spot
Here is a list of things that we have done / changed / looked at so far without finding any problems:
- Steering rack changed (twice)
- New Wishbones left / right
- New Wishbone bushings left / right
- New Track rod ends left / right
- New Front shocks left / right
- New Strut mounts left / right
- 4 Wheel alignment on laser system
- Steering column inspection, check for play or wear
We have looked at two other cars which have the very same problem.
Any ideas as to what might cause this?