Drive shafts are balanced to prevent vibration, if yours is doing it you need to check your universal joints, and whether the shaft has been dented or if one of the weights used to balance it has fallen off.
The drive shaft can vibrate due to damage or if the balancing weights fall off. If the weights are lost, you may take the shaft to a shop that has the equipment and have the shaft balanced again for typically under $50.
As you increase your speed the whole car will begin to vibrate, not shake but vibrate. The images in the mirrors will be just a blur.
See if your drive shaft going to front end is bent.
Tires and/or wheels need to be balanced? Bent wheel? Rear wheel drive? Drive shaft may need to be balanced
The critical speed ratio of a shaft is a dimensionless value that indicates the relationship between the operating speed of the shaft and its critical speed, which is the speed at which the shaft experiences resonance and can vibrate uncontrollably. It is defined as the ratio of the shaft's operating speed to its critical speed. A critical speed ratio of less than one means the shaft is operating below its critical speed, while a ratio greater than one indicates it is operating above critical speed, which can lead to increased vibrations and potential failure. Proper design and analysis are essential to ensure that the operating speed remains safely below the critical speed.
Its the gear that connects the speed sensor shaft to the transmission
It could be from a worn out U-Joint on the drive shaft or it could be one or both of the rear wheels are out of balance.
In the tail shaft housing. you have to remove the drive shaft and the tail shaft housing to get to it.
on the output shaft of the transmission, close to where the drive shaft enters
It's not the driveshaft. You have a bad transmission.
Variable Frequency Drive
Have the tires balanced and try it again. Also have the drive shaft checked.