I just bought a 98 navigator w/5.4L and 4wd and it has 47k on it. I was just wondering if there is some things that I should know about. What are the major things that go wrong with these things and what can I do to stop some of these problems from happening? Anyway I'm from Pennsylvania and if anybody needs anything just hit me up! Thanks guys.

 

only thing that comes to mind is the shorter thread count on the spark plug holes. im sure some expy experts, or 5.4 know it alls can confirm this.
-Patrick

 

Is there a certain torque that I need to keep the spark plugs at? Thanks for your help!

 

also need to check the bottom of the inner doors for rust... i had a 2000 and this was the only factory problem i had...i put 171000 miles on mine and the thing is still going...My trany blew planetary gear at 168000 ,but the motor on fords analysis computer, showed it running at 98%... which is excellent for the age and mileage of the vehicle. i finally trade in for a 2005 expy just to have a new one...so good luck and enjoy

 

Thanks guys for all your help, this is my first 4wd. I just wanted to know the normal problems with these things. It seems like these things are pretty reliable. Also does anyone know the routine maintance, like tranny fluid, diff oil, etc.?