I had an 83 300D Turbo which has a rear end howl issue. It has been that way ever since I got the car, which now has about 260000 miles on it, and I only hear the howl when I am applying throttle, when I let off the throttle it goes away. I am going to be replacing both rear axels in the near future since I am starting to hear some noise from the CV joints on 1 of the axels and figured since I am replacing 1 I might as well replace both. I have been told the whine is due do a worn pinon bearing in the rear end and that is putting excess strain on the gears in the rear end. Is this true and if so how hard is it to correct? Also while I am replacing the rear axels, should I be replacing the rear wheel bearings while I have everything apart and how big of a job is that?