Highway Vibration at 60-65mph - Unbalanced Driveshaft

Suspensionintermediate✓ OP Confirmed

Problem

Severe vibration and deep droning/howling sound occurring between 58-70mph that carried through the cabin and under the seat. The tone deepened when decelerating. The vibration persisted even with the rear of the car jacked up and CV shafts disconnected.

Deep howling/droning sound between 58-70mphIntense vibration felt through center of car and under the seatVibration tone deepens when letting off the gas and deceleratingHard impacts felt when snapping on/off the acceleratorSteering wheel does not shake significantlyVibration present even with rear wheels removed and car on jack stands

Root Cause

The driveshaft was out of balance. This was confirmed after extensive troubleshooting that ruled out many other potential causes. The issue may have been caused or worsened by u-joint replacement without subsequent rebalancing, or by incorrect reassembly of the two-piece driveshaft halves.

Confidence

High confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted January 2020 on SupraForums.com