Need a little help on this, my truck has started making a grinding/vibration noise at a certain RPM lately. It happens when just starting out driving when I get to the 2nd line above 1000 on the tach, I can feel it in my feet a little bit and you can hear it, it only happens for just a little bit then goes away when your out of that RPM. I replaced the loose U-joint thinking that was it but it was not. Any other ideas? Could the T.Q. make a noise like this or prob. not. It feels like its coming from my feet area up to the engine or something. It is a 4X4.

 

Bump:

Fixed a broken u-joint, found that the transmission mount was also broken, fixed that and still nothing. Deep sounding/feeling vibration in the floor board area. Any ideas? Just in a certain RPM range, will not do it in park or neutral going down the road, only when it's trying to drive the tires I guess. Flexplate or Torque Converter? Thanks