Driveline vibration

Hi ive researched all throughout the forum searching for a solution i have a vibration in my truck between 30-40 mph i have replaced all u-joints and carrier bearing. I also had a small leak a few drops from drveshaft output so i replaced the seal but it is still leaking the driveshaft also has some play from the front where the yoke and trans meet. Please help thanks

 

Lifted? Larger tires and wheels? Only at 30-40mph?

 

I have a 3” leveling kit and tires are 265/70r17 however i do t think this is the cause because i had this vibration before i put the tires and leveling kit in and yes only between 30-40 mph

 

Start with the cheapest and easiest.
Balance/rotate tires.
Alignment.

 

I forgot to mention i also did that already sorry the alignment and wheel balance was done after the leveling kit was installed

 

Crawl under it and see if a balance weight has been knocked off the driveshaft.

 

I just checked and they are all still there the only place i feel play is in the front of the driveshaft where the yoke meets the transmission thats where i also feel the vibration

 

I also noticed it only vibrates when I lightly accelerate up

 

I also have the same issue. But I'm lifted with slightly bigger tires. I had it after I lifted the truck but the vibes went away after I shimmed the carrier bearing. Now it seems to come back in the cold weather (sub 20 degrees) and only when I lightly accelerate.

 

Yeah i saw the carrier bearing spacers might try it i have a 3 inch leveling kit and larger tires. I just changed my transmission mount ill keep you updated if that fixes it