Owners of 2010-2014 Buick LaCrosse and 2014 Regal GS AWD models may comment on a squeak or chirp noise from the rear of the vehicle, noticeable at low speeds with the window open. This is likely a squeak at the axle-to-seal interface due to a lack of lubrication.
Replace the left and right axle seals and lubricate the seal lip area and the inner part of the seal with clean axle lubricant, GM P/N 88900401 or equivalent.
Replacement axle seals are available as follows:
20986535………Seal, differential drive (first design, black seal; pre-2012)
22845699………Seal, differential drive (second design, yellow seal; 2012-2014)