Tl* the contact owns a 2008 toyota sequoia. the contact stated that while driving approximately 70 mph and depressing the brakes going downhill, the vehicle started to shake violently. the vehicle was later taken to the dealer. after diagnosis they advised him that they were unable to diagnose the failure. the vehicle was not repaired. the manufacturer was contacted and offered no assistance. the failure mileage was approximately 50,000. the current mileage was approximately 116,000. the vin was unavailable.