The National Highway Traffic Safety Administration (NHTSA) opened a preliminary evaluation into General Motors’ eight-speed automatic transmissions. The federal probe follows widespread complaints regarding the 8L90 and 8L45 transmission models.
Drivers report violent shuddering or vibrations similar to driving over rumble strips. Investigators are testing if factory transmission fluid absorbs moisture and causes premature component failure.
Federal scrutiny could lead to a large-scale recall if the agency identifies a safety defect. Separately, a new class action lawsuit targets GM over alleged defective brake vacuum pumps in other models.