Reply to "Driveline vibration after lowering car?"

CV (constant velocity) joints, done correctly, should eliminate the vibrations that you are experiencing. As Joe demonstrated, U-joint systems have changing velocity aggravated by high angularity and cause a torsional pulse preserved as a vibration.

Virtually no one uses U-joints for axles any more largely for that reason and for many years now units that can handle lots of power are readily available. Can you imagine a front wheel drive car with U-joints? Take a look at the wild angles Porsche cars have at there rear suspensions. Starting my build, I knew one of the first mechanical changes for #5715 would be CV joints.

When any one thing is changed from stock (ride height) there is usually collateral consequences. Often that's why people are unhappy with a mod.