One problem related to steering gear box has been reported for the 2003 Mercedes Benz ML320. The most recently reported issues are listed below.
Car makes a "washing machine" type nose when the steering wheel is turned. Mercedes dealer evaluated and found the steering gear box/rack & pinion is "worn" and should be replaced. Although dealer recommended replacement of part they did add a lubricant to power steering fluid to "eliminate" the noise (which is still there presently). Warranty company refuses to replace rack & pinion because they state part is still functioning as intended. However, if part completely fails and the steering goes out, I could be involved in an accident, possibly causing death or injury.