Vibration at 25-40 MPH

2011 TRD Sport DCLB 4x4 with just under 80,000 miles

I just drove my truck from MA to NC and back, putting close to 2000 miles on it over three days. So, with over 30 hours behind the wheel I started to notice this more.

Basically, I get a vibration that feels like a wheel bearing issue at moderate speeds (25-40 MPH). At first I thought it was my snow tires, but the summers do it too. I swapped the front two hubs and bearings as well, but no change (I don't regret that, since it sounds like I wouldn't be too far off anyway). It's very subtle...impossible to notice on dirt roads, for example, and I don't think anyone other than me would notice it unless I specifically pointed it out.

It does it on or off throttle and in 2 HI or 4 HI. 25-40 is where it is noticeable. At higher or lower speeds it does not do it.

Few things that are probably important: Truck has a 2" suspension lift from aftermarket rear leaf packs and 5100s/OME 884s up front. While it would benefit from UCAs, the alignment went good enough so they aren't a necessity. I did this in the winter and never noticed a vibration then, but the roads were almost always snow covered so that could be why. I started to notice it once we had bare pavement again. That said, most of the threads with a similar issue seem to indicate that it's only an issue on throttle so I'm not sure if that has anything to do with it.

Also, I get a clunk about 1/3 of the time when stopping or starting from a light. I find that if I brake and accelerate gently it does not do it. I've kept up on greasing the driveshaft zerks, but it sounds like it could still be u-joints going. But, again, why would it vibrate when I'm coasting then?

Any ideas would be great...thanks!

 

Sounds like a U joint to me