New tires = new vibes?

About 3 weeks ago I got some new shoes for my Taco. They balanced and did a 4 wheel alignment. No offroading since...

I have been getting a vibration between 65 and 70 MPH. It is not constant, it comes and goes. It usually vibrates most as I am reaching highway speed when merging. Then it will calm down. Sometimes it comes back. Its strange...

It does not seem to be getting any worse, but it is not getting any better either. I want to act on it before anything else goes wrong. The tire wear is normal so far, it is hard to tell with brand new tires.

Its annoying. I think it may be a lousy balancing job but I dont know. The allignment seems ok, no pull to either side and the numbers were right where they should be.

I plan to take it back and have them do it right but I just want to know what I am talking about in case they try to dick me around.

What do you guys think? As always, I appreciate your help!

 

More info...

09 4x4 DCSB no TRD smooth as silk before this on the stock "Dunflops"

 

sounds like their balance machine needs to be calibrated. once had new tires put on for upcoming 1500 mile trip, new ones shook about 65 mph then would smooth out. rebalanced and rotated same problem. put truck on a lift and spun the tires, turned out to be bad u-joint. do not know why it didn't vibrate before. you could not get the u-joint to move, had to remove and just one end was bad. how did they do a 4wheel alignment on straight rear axle? fancy way to justify charging you more.

 

Thanks for responding guys!

I was wondering that about the alignment myself. It was included so I didn't give it too much thought. I will look into road force balance. Hopefully its not the U's. Similar sounding symptoms though...

 

I brought it back and they re balanced the tires for free. They must have half-assed it the first time. All good now!

 

Mine does this between 50-60mph. Seems like once the tires warm up it goes away.