Federal safety regulators have gotten four complaints about half-shafts coming loose in Ford GTs but are not conducting a defect investigation. If the half-shaft separates from the transaxle, the rear wheels lose power.
Ford also acknowledged a much wider problem - at least 60 incidents of broken shaft bolts - but said it is not a safety issue. A spokesman says Ford issued a service bulletin on the car last year.
The failure occur during acceleration but not at highway speeds. Installation of replacement washers can prevent failure. About 4,000 of the two-seat, midengine, high-performance cars, priced at more than $150,000, were built as 2005 and 2006 models.