What is that vibration I feel around 1800-2000 RPM?
This problem is an unbalanced driveshaft. Most people with the problem feel it at its worst between speeds of 90 and 120 MPH. Others claim they can also feel it by slowly bringing the RPMs up to the 1800-2000 range with the car in park or neutral. But that isn’t necessarily the same problem. Some even start to feel it as low as 60 MPH. It usually starts with a mild resonating vibration you can feel through the gas pedal. Then in at 80 – 90 MPH, the vibration intensified and feels as though it’s coming from the center of the car. It seems cars are coming off the assembly line with the unbalanced drive shafts. A Technical Service Bulletin (#674101) addresses this calling for replacing the stock driveshaft with a 3rd generation all-aluminum driveshaft (part #10085375) which came with the 1LE equipped cars. Although there have also been instances prior to the TSB where it was replaced with the standard 3rd gen steel driveshaft (part #26004464). Either seems to work just fine (although the
