I am getting vibration (similar to lane assist) at speeds of 40-42 and 25-33. Tires are new, balanced and a front end alignment was done on vehicle. Range Rover Palm Beach states this is normal and that other 2021 models do the same thing. I say this is NOT normal for a car with 34,000

 

Not normal. Take it back to the dealer or take it to an independent alignment shop.

 

Land Rover is saying this vibration is within engineering spec!!! They refuse to fix. Replaced motor mounts but it did nothing still vibrates like lane assistance safety feature

 

Car has been at dealership three times for a total of 40 plus days

 

That is strange for this to happen at the speeds you are mentioning. Have you tried turning off lane assistance and driving without it?

 

Lane assist is off
this is report from a European mechanic (not related to Landrover)

There is a noise and vibration that is felt throughout the body of the vehicle and especially in the seat. The noise does occur at 42-43 mph and is very consistent. During multiple road tests, we were able to conclude that the noise/vibration occurs specifically in the 7th and 8thgear at 1000 rpm. If the vehicle is entered into the manual mode and the vehicle is in 6th gear at 42-43 mph the noise/vibration does not occur which indicates that the issue is drivetrain related, and the issue could be occurring possibly within the transmission or transfer case.

 

Is your vehicle still under warranty? Interesting that the independent mechanic thinks it is coming from the transmission. I would share this information with the dealership and see if they can confirm this finding. By the way, you are in the wrong forum as this one is for the fifth generation Range Rover...