Every now and then, about 40-60MPH, my truck will start to violently shake like the front tires are coming off. Took to dealer, they claimed to be called 'death shake' and was inherant of earlier 1994 trucks but not heard of for 2011. If I put in neutral, the shake will NOT stop but when I brake, it will. It is not consistent nor can I make it happen. Seems when I go over a pothole or some rut in road will it start. The local dealer did replace the Rancho shocks as a possible TSB item, but still happening. It does have a steering stabilzer as well. NO, it is not unbalanced tires, the shake is much more severe than tires out of balance or tires out of round, plus would happen all the time. Any ideas what this could be?? Thanks.