So I have a 05 LS430 and while accelerating in 1,2 and 3rd gear there is a noticeable driveline vibration that is prominent at 2K-2.5K rpms. This vibration can be felt mostly in the drivers seat and steering wheel. Once up to speed the car is dead smooth. I have two sets of tires and wheels (winter/summer) and it's present when either set is on the car so that rules out tires/rims. I still drive my old 2000 LS400 and my dads 09 LS460 and both cars are dead smooth while accelerating so I don't think I'm being hyper-sensitive.

Any ideas guys????

Thanks in advance for the input.

 

I would start by having the engine / transmission mounts checked.

 

First I totally agree with what caddyowner said, and that is where you start is with the motor and trans mount.
How many miles? then try jacking the car up, and then yank on the wheels and tires. This could be a wheel bearing or something like that. i doubt tie rod end or anything but you should knock around on your car when you have it jacked up and see if you can find play in anything. Usually things like this come out of the front end. of the car

 

So I replaced the trans mount and that didn't correct the issue, i suppose I'll move on to motor mounts. I just turned 76K miles, are motor mounts prone to failure at this mileage????