Vibration after 5100s

Hey i installed the 5100 shocks in the front and set at 2.5. after a week or so i notice a vibration at highway speeds that feels like my truck is bouncing. I have had a 4 wheel alignment done after shocks were installed and was wondering what the problem is and how to fix it?
thanks,
Dylan

 

Its either wheel balancing or drive shaft vibration.

Most likely the wheels need to be balanced because drive shaft vib usually occurs at slower speeds.

 

Yea i can tell it rides stiffer but i already had it aligned so i guess ill try balancing and see if that fixes it. I also have a warranty on the alignment so i will get that redone also.