On the M272 V6 petrol engines sold between 2004 and 2007 (with engine numbers below 2729..30 468993) the balance shaft gear wears out early. The timing shifts: check engine light, misfires, and the car can even stall. The repair is a job costing over 4,000 dollars, because the engine has to be opened up.

The complaints turned into a class action in the United States (Suddreth and Dunton v Mercedes-Benz USA). The court finally dismissed the claim: the gears fail between 60,000 and 80,000 miles (roughly 95,000 to 130,000 km), so outside the warranty period, and the maker was not held liable. According to the case material the maker knew about the fault, issued repair bulletins, and eventually switched to a stronger gear.

If the service book shows a completed balance shaft repair, the stronger gear is fitted.

The case papers also name the M273 V8, but the M273 description does not cover this fault. This applies only to the M272.