Re: Jays comment on lowering the pressure: most Everyone hears it helps to lower, but it wasnt until playing with the on board air in the hummer how much i learned about it. Anyone thats gets offroad ought to have a little compressor with you, and then play with it to learn what pressure is right for your truck/ tires in mud, sand, etc.
The difference in 5 lbs too little or too much is amazing. I learned in my suburban that going from normally 65 down to 25 helped a bit, but once i hit 20- WOW! In my buddys 05 2500 dmax, it was 30-35 in front and 15 in rear for the magic spot.
Different tire makes a bit of difference in what is best also. So many of you guys probably run same tires that one weekend experimenting could help yourself and others.
Sorry to side track, and sorry to hear of the continued problems. When i owned the truck equipment shop we would fix these issues for dealers and owners alike. No one issue unfortunately- its like chasing an intermittent electrical problem- just a p.i.t.a. I would push for new fill hose and a tank drop to start.