Engine Grinding Noise problems of the 2003 Dodge Durango

Front suspension - drive train - locks - axle - power steering pump vehicle has had consistent front end grinding noise since 30,000 km's. Ball joints have been replaced, front axle spyder gears have been replaced. Previous 1998 Durango had same problem - fix was front wheel bearings. 2003 Durango - dealer says that it doesn't require replacement. Noise and grinding only happen at slow speed turns left or right. From stop to light acceleration to hard left or right turn, new noise from rear axle - limited slip unit now getting louder. Axle oil and limited slip additive have been replaced with factory Chrysler oil additive. Indicative of same problem with 1998 Durango that I had, when rear axle pinion bearing was heavily scored. In that incident the same maintenance was done, but repair was out of warranty by 3,000 km's and Chrysler only paid 50% of repair of $700. 00. Oil changes on complete drivetrain was $590. 00 (4x4 with skid plates). This appears to be a metal fatigue problem in combination with engineering specifications that are too wide in tolerances, which allows failure of components to compound problems and create longer term damaging results. Ever since Dodge trucks went to maintenance free front axle bearings (you can't pack bearings with grease), poor limited slip tolerances in rear axle, and transfer case that's electronically operated, the drivetrain and front suspension components have excessive loads and poor quality components. Both Durangos that I've owned have had 5 wheel alignments (constant pulling to the left) and no off road driving. Strictly highway and city driving. I purchased factory extended warranty on 2003 Durango which I highly recommend. So far, out of pocket expenses have been minimal, but Durango spends too much time in the shop and is very inconvenient to have serviced constantly. Never had issues with warranty parts or dealer not doing warranty recall work.