I had my ring and pinion replaced a few thousand miles ago. It has started to howl again so I took it back as I only have about 100 miles left on warranty. There is also a slight "shutter" when taking off from 0-2 or 3 mph only when the wheel is slightly turned, its fine in a straight line or after up to 5 mph and faster. The service writer told me the tech said the howl was the turbo and not the rear end and that he put additive in the rear. I told him it was funny that the howl goes away when you let off the throttle and he said it was in the turbo and there is nothing to do, and that he drove the truck around their lot in circles and figure 8's and the shutter was better if not gone. I called back and said you cannot put additive in these AAM rears and he then said they didn't put the additive in but the shutter was gone. Whatever. I went there and drove it with the tech and the same thing. And the tech didnt check the shutter at all, he didn't know anything about it. The writer never printed it on the check list. He then told me going to DC wouldn't do any good cause the "girl" that is the regional rep cant check her own oil and wont know anything and wont approve any work. I called DC and made a report but dont know what to do. I left the truck there for them to check the shutter and the writer didn't want that at all. He crumbled up my paperwork and threw me my key. I left it there and told him to have his boss call me as it wasn't healthy for me to deal with him anymore. Its an 03 2500 4x4 with the 10. 5 AAM. 69915 miles. Any advice? contact numbers?