First time on here. Willing to try anything for answers. My 07 3500 4w drive dually has problems. Been to two different dealers, complaining about no pulling power in soft dry dirt. I pull about 7500 lb trailer everyday on construction sites. I get into soft dirt and won't pull, revs up to only about 1500-1800 rpm and sits there. Try using 4w drive, no help. 3 different times have to be pulled out of 6" deep dirt ruts. First dealer replaced the pressure solenoid something and they told me they rebuilt the trans. No help still having same problem but now when I put into park, the damn thing thinks it is in reverse and starts honking the horn like crazy. Have to turn of the truck and then put in park. Oh, buy the way cannot start in park, have to start it in neutral. Lots of info here, any comments suggestions. Buy the way I took to a different dealer today and they said they could not duplicate any of the problems....?