I have a 2005 FX4 Regular Cab that recently had the rear diff driveshaft seal replaced. I also had them do a front-end alignment. For some reason when I am in 4HI in the rain, I seem to notice a lot more noise. Also, after driving 5 or more miles in 4HI in the rain, I seem to smell something burning (the tires perhaps) after I park the truck and walk past the front tire well.

 

Why are you driving on the street in 4X4 HI. the way the front end grabs when you turn, you are going to break something