jimmysb1973

I have bad vibration in my truck so I figured the tires needed to be balanced or replaced. It was time for new tires so I put on BFG AT 305's. The tires I had on before were BFG AT 285's. After having the tires mounted and balanced I still have a bad vibration between 45mph and 50mph. But it lessens at about 60mph but its still there. The vibration is not in the seat or steering wheel its in the center and you can feel it all over. I was thinking that they need to be rebalanced but I was also thinking it could be the Ujoints in the drive shaft going bad. Or is this just common with this size tire? Can anyone confirm or have another possible cause. Thanks in advance

stres823

Sounds like bad u-joints to me. Crawl under and check them. Is there a "clunk" when going from neutral to low or reverse, (auto), or changing gears under a load ,(stick).
Crawl under, with no load on the drive shaft, (level ground), in park. Manually rotate the drive shaft. Look at the u-joints. You should be able to tell rather easily if they're bad when rotating to stop and back.

tdsports

I had the same problem a while back and replaced u-joints and tires and the vibration was just the same. I replaced the drive shaft next and after that it was good as new. Dont know if that helps but it was an on going problem for about a year.

Chris0

As stated above it sounds like U joints. I had the same vibration (45-55ish) then it would go away at higher speeds. It progressed quickly and wound up being the U joints. good luck