You say "with the wheels on the ground", are you lifting the car using the cross member?

Try supporting the car with jack stands under the control arms. This will more closely simulate the actual conditions. It might assist you in locating a "bind" if there is one.

Have you done anything else to the steering? Tie rod ends, idler bushings, etc.?

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“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
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