I have a 1999 F150 V-8 5.4. I need to replace the alternater. Can anyone please tell me how do i release the tension thingie? In the old days they had bolts to simply turn but his one does not.

 

On my 03 I put a wrench or socket wrench, I can't remember which, and push against the spring until you can slide the belt off. There is very little room on my 5.4 so you can look forward to scratching the **** out your arms when you do this. Wear long sleeves. Good Luck.

 

there should be a square cutout in the arm that the pulley attaches to you put a 1/2" drive ratchet in it and pull on way or the other (one way it will move the other it wont ) and just slip the belt off and gently release the tension on the idler BE CAREFUL IT HAS A FAIRLY HEAVY SPRING IN IT and if you get you hand between the ratchet and any thing else it hurts :o