02 3500 nv5600 2wd quad cab. 233k.   I've been as diligent as possible regarding preventative maintenance, but you know how it is, entropy is a ***** and things go wrong.    Now getting ready to put down some serious miles - long distance cross country driving soon, multiple times this spring and summer from NJ to Florida towing a haulmark 20ft car trailer (approx 7,000 gvwr).   Here is a list of the repairs i've done, as well as some pro-active maint in anticipatio