2010 Trd Sport 4x4 DC Vibration!! Help!!!!!

So I just bought a 2010 Tacoma 4x4 Trd Sport double cab last Monday!
Truck has 84,000 miles.
When I test drove it at the dealer ship, I noticed that it had a lot of vibration while taking off!
Of course my first thought was carrier bairing. Sure enough I got up under the truck and went to wiggle the drive shaft and it had quite a bit of play.
Dealership deducted $200 off price of truck so I could replace the carrier bairing.
I've noticed that previous owner has installed new u-joints, because he was having issues with it, but he didn't change the carrier bairing. However I did and it's not vibrating near as bad as it was but still has some vibration. I need some help from somebody that might no what's going on with it?
Also I guess the previous owner while changing the u-joints must of hit the driveshaft with a hammer or something and it does have a small dent in it up by the transmission. I'm wondering if this has something to do with it?