Random Driveline Vibrations

I was getting some vibrations at 55+ mph so I decided to replace the Center Support/Carrier Bearing on my 06 DCLB Tacoma. Went for a test drive and it rode really smooth. Now 2 days later the vibes are back and seem to be a bit worse but they are intermittent. I'm scratching my head wondering what the heck is going on. The flange bolts on the drive shaft and the bolts on the carrier bearing are good and tight and the U-Joints are all in great shape. I'd like to hear your thoughts guys.

Thanks,

 

Here is the link for your reference. Hopefully it can help you to solve this issue.
https://www.tacomaworld.com/threads/drive-shaft-vibrations-solved-step-by-step.244535/

 

I would go back and double check your u bolts. If they are original they need to be replaced.

 

The U Bolts on my axle/leaf springs?

 

Sorry I meant u joints. The ones in my 2013 were toast after 100k miles.

 

They seemed fine to me, I had them replaced back in the spring, or 5K miles ago. The strange thing is these vibes don't occur until after I drive 5-10km when everything is warmed up and then it comes and goes. Also no lift, it's all stock.