I believe the technicality that makes them illegal is because most beadlocks as well as things like full hydro and some suspension components have never been tested or approved by D.O.T. They may or may not be capable of standing up to that scrutiny, but have not been put thru it because the manufacturer hasn't gone to the time or expense to get them approved, or they know that they simply would not be approved. Some extended brakelines would be illegal because they don't have a D.O.T. number.
