One problem related to steering gear box has been reported for the 2006 Ford F-250. The most recently reported issues are listed below.
Our Ford f250 4x4 diesel truck has a steering problem. It's locking up when turning left to right. We had 2 occasions where we just missed being in an accident. When the steering locks you can not do anything. The vehicle continues in the direction just prior to the lock. The wheel needs to be turned back left to unlock and this is not always possible. We live on a curve road and it's very dangerous. We took it to the dealer in folsom CA, they replaced the steering stabilizer, which did not solve the problem. The vehicle will be towed back the 60 miles today and we will not accept this vehicle.