Quote:
Originally Posted by woodchuck1
When the power is off, and parked up, there is amazing play and clunking if you try and move the steering wheel, so there is (In my mind) something very wrong with the my steering setup (on the list for the dealer).
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X3s have electric power steering. There's no mechanical connection between the steering wheel and the front wheels. The steering wheel is more like a rheostat or a dial that actuates electric motors via wires. Any sound made by turning the wheel with the power off is probably not related to your tire wear problem.[/QUOTE]
Nope. It's electromechanical. Like all BMW's with EPS, the steering assembly swaps hydraulic fluid for an electric motor with a variable planetary gearset. Make no mistake, BMWs of late with EPS are especially lacking in road feedback, but not entirely devoid of it. If you push the car hard enough, you will feel kickback at the limits of adhesion. This nods to the mechanical linkage. EPS makes for a very refined steering experience, filtering out all but the most important information. The "unfeeling" nature of EPS systems is as a result of the electric motor's ability to offer the right amount of assistance at every possible moment. What we describe as "road feel" is actually an insufficient amount of assistance, whether hydraulic or electric. However, the position of the steering rack, as well as the rising angle from the front axle to the input (steering gear), can have a dramatic effect on road feedback. The X3's lack of on and off center feedback comes as a result of electric motor remaining off until the computer receives steering input--that is, the delay as the motor reactivates.
The only electric power steering that behaves the way you describe has just debuted in the new Infiniti Q50.