Truck Forums - ABS light on and 4x4 HI light flashes...

Hi everyone, I have an 08 AWD with 18k miles. For 3 weeks now my abs light has been coming on and the 4x4 HI light flashes every 10-30 seconds, lasting for 2 seconds or up 10 seconds at a time. When I turn the truck off then back on the light goes out and doesn't come back on for a day or two (depending on how much driving I do). Before the lights come on I can feel a grinding sensation in the gas pedal when I'm accelerating. I can also hear the noise in the engine or the drivetrain (it feels like its coming from the front differential but the noise is coming from the engine or it sounds like it is). I've taken it to the dealer twice (once when the lights were off and once when they were on but they have not been able to find the problem because they say it’s not happening for them). Has anyone else experienced the same thing or heard of this problem? Any info would be great. Thank you!