I have a 2004 TL A-Spec and in the past few months I have had vibrations in the steering, floorboards, and seats between the speeds of 60-70 mph. There is no vibration above or below these levels. I have had the tires rotated and balanced and am still having the same issue. I also had the rims checked to see if there were any bends and there was nothing there either. HELP!!

 

FWIW axles can cause acceleration vibrations, might not hurt to inspect the boots on yours. Possibly one is torn, spat out grease and is now dry/failing?

Good luck.

 

I have the same problem, 04 TL 6spd, I just bought new wheels n tires, had the car aligned, checked wheel bearings, tie rods, ball joints, and everything is in place n no play at all. I even replaced the drivers side axle bcuz that's where the vibration comes from n it didn't help....