If the noise is comming from under the hood you Powersteering Belt may be slipping and the Powersteering Pump could be low on fluid, need a filter change, or even have an air leak on the suction side.
I try to avoid avoid turning my wheels all the way to the limit of the travel as much as possible as it stresses the system.

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84 300D, 82 Volvo 244Gl Diesel