Sudden Steering Wheel Vibration 50-60 MPH + Deep Whine on Deceleration

[Hooty]

Hey there,

I had a trusted mobile tire service install a set of DWS06+ in the correct size on my factory contours yesterday. The tech let me know that both rear wheels are ever so slightly bent, but that I should not be at all concerned. The car drove without any steering wheel vibration prior to the installation and drove exceptionally well on my way home from work that evening. The next morning, the following two issues appeared:

Whine: A deep whine when decelerating in gear. The first 1/4 of my commute involves two miles of stoplights and was able to repeatedly replicate the noise. I noticed that the noise only occurs when decelerating. The noise is most pronounced when decelerating in any gear but can be heard with the clutch depressed or in neutral with the clutch let out.

Vibration: On the highway, I noticed significant steering wheel vibration between 50 and 60 mph. I could not feel any vibrations in my seat or elsewhere in the car and the severity of the vibration dissipated after crossing 60 mph. In contrast to the whine, I cannot easily replicate the vibration which appears to depend on the surface condition of the highway. Interestingly, the vibration occurs without fail on a particular stretch of overpass, approximately 1/8 mile. The condition of the overpass has not changed.

I should reiterate that both of these issues emerged after the tires were replaced. Nothing on the suspension or driveline was harmed or altered prior to or after the installation. For what it's worth, the following has been changed in the last 4,000 miles:

Belts, Pulleys, and Tensioners Replaced
Bilstein B8
H&R Sport
Zimmerman Rotors (calipers are functioning normally, no "hot" wheels)
Hawk Pads
Brake Fluid Flush
Differential Fluid Flush
Transmission Fluid Flush
Engine Oil/Filter Replaced
LCA Bushings Replaced
LCA's inspected

[scoobiedoo2029]

wheel balance issues on a e36 are very noticeable, some people road force balance their wheels, i have not been able to get a local shop to do this, my local guy does a good enough job. issues usually are at about 55/65 mph it seems.

[Hooty]

Spot on. I had the car balanced for the third time this morning and all the issues are gone. According to this new shop, which is a mobile tire service specializing in higher end vehicles, all four wheels were off balance. I have never experienced a vehicle with four wheels out of balance so perhaps that explains the strange symptoms.