My 2019 E450 started with a driveline humming/grinding at 1500 miles. It went to ford and MORryde suggested a driveshaft realignment and balance. It helped quiet the noise but it was still present. Manageable, but present.
At 10000 miles, it began to get really loud again. 63-69 mph range in sixth gear, under light constant throttle, it would just sing. I mean vibrating the floor in the back.
Once again, it went back to get fixed. This time it was at MORryde's factory in Wakarusa while my Busch was getting repaired at Thor. Whatever they did made it worse.
So now it is at Gator Ford again and I was able to duplicate the problem for their technicians. They are thinking it is at least a bearing or the differential.
I took a sample of the differential gear oil before it went to ford and sent it to Blackstone labs. The fill plug is magnetic and had quite a bit of metal "fur" on it. Their report states that the oil had metal in it that is consistent with 36000 miles of wear. My coach has 12000 miles. So I'm hearing that the wear is accelerated 3 times more than it should be?
I am hoping whatever they do fixes it.