Vibration on acceleration

Had my new Tacoma 4-D PreRunner 2WD for about a month now and and noticed a vibration through the steering column when accelerating -a little in first gear but a lot in second before smoothing out. Took it to Toyota and they said there was TSB on the problem and they would repair under warranty. Picked it up from them today and vibration is still still there.
I've made an appointment for next week but after seeing some posts here I'm not real confidant of a good outcome. Is this fixable and does Toyota even know the source of vibration?
Thanks for any input.

 

torque spec on rear u bolts is low


I tightened mine to 50 each, then to 80, and guess what ? my vibes are GONE

I think you need to ensure the u-bolts are 80ftlbs before giving up