2006 Lincoln Navigator owned or leased by my daughter/son in law almost lost left rear wheel on January 27, 2008. Upon inspection, left rear wheel was found to be loose. When hub cap was removed it was discovered that two of the threaded wheel lugs had broken off with the lug nuts still on the broken part of the studs. The other four lug nuts where loose. This vehicle was carrying three baby girls (triplets) and their mother and father when this incident occurred. The vehicle was within a minute or so of loosing the wheel. With potentially disastrous results. The wheel studs should never have separated even if they were overtightened. The threads should have stripped first. Wheel studs may have been defective and this should be investigated. Vehicle was returned to dealership for repair.

- Carle Place, NY, USA