Replaced new drive shaft but still vibrates but...

Found it's my drive shaft. Had it replaced w OEM but it occasionally vibrates at 35 and 45 mph but sometimes it does not. Any thoughts? I googled and it could be imbalance or U joint but noob. Advice?

 

Was the new drive shaft balanced? Did the new shaft have new U joints or reuse the old ones? There are a few obvious things to verify since you already replaced with OEM. Further, could not be the shaft... do you know for sure it isnt a failed wheel bearing? CV? Wheel(s) out of balance? there are frankly tons of things that can cause vibrations on our rigs

 

all wheels are balance and rotate. New OEM. I wonder if U joint or shaft needs to be balance? I read it somewhere. Same vibrations at 45 mph as i steadily accelerate but if I punch it. No vibrations.