WHEN I REPLACE MY SHOCKS I NOTICE A LONG BLACK BOX WITH A COUPLE OF HOSE ATTACHED TO MOUNTED BETWEEN THE FRAME RAILS JUST IN FRONT OF THE SPARE,IT'S ABOUT 4"BY 4" BY ABOUT 18" INCHES LONG DOES ANYONE KNOW WHAT THIS IS AND IS THAT BLACK GOUP ON THE FRAME TOXIC. 1998 F150 SUPERCAB LARIAT ,THANKS FOR ANY REPLIE. KJ

 

I believe the box is a vapor separator for the gas tank emissions system. It makes sure that gas vapor, and not liquid gasoline, goes up to the carbon canister for storage.
The black goop on the frame is a wax coating for rust prevention. It is somewhat "self healing" against stone chipping, as compared to just paint. I don't think its toxic per se, but I have never felt any urge to lick it or see if its self healing properties also apply to humans. It sure makes a mess on clothes wherever it rubs, that's for sure!

 

THANKS FOR YOUR IN PUT GRANPA,I BELIEVE IF THE BLACK GOUP WAS TOXIC MY ARM WOULD HAVE FELL OFF BY NOW.YOU JUST ABOUT HAVE SCRAPE IT OFF WITH A KNIFE.SEE YA