The drive shaft can be reindexed - mark rear shaft & yoke with a center punch, Not paint.You will be putting it back together in the original configuration. Take a picture of the step less ear clamp, so it can be put back in the same orientation. It has balance value. The yoke has 2 spline out...
I have the same problem, vibration at all speeds, sometimes worse than others. I was a Auto Mechanic, Sr to one of the largest energy companies in the east, for 38 years, now retired. I have dealt with dealerships many occasions. The standard phrases are THEY ALL DO THAT or I DON"T FEEL...