Blobbo

New here but just wanted to share my experience changing out the belt tensioner on a 4.2 V6. The idler pulley crapped out, which is an easy enough replacement, but the belt tensioner wasn't moving (maybe the reason the idler failed) so I decided to replace that as well. There is a single T50 Torx bolt holding it on and it was in there so tight that it eventually broke half way out.

I removed the alternator and then took the bracket out to get access to the broken bolt. Nothing I could do would make that bolt move. I drilled it out, tried an easyout, used copious amounts of liquid wrench, heated it up and nothing worked. I eventually took it to a shop for extraction. They charged me an hour's shop time. They must have had a nuclear bolt extraction machine .

The new tensioner from Ford comes with a new bolt (the cheaper offshore replacements do not). The new bolt is Grade 8. I suspect Ford knew there were problems and provide a stronger bolt as a replacement.

It has been a rather frustrating experience. I didn't see any similar threads so I thought I would start a new one to help anyone out who experiences the same issue.

Marc D

I don't know how old your truck is but any bolt attached to a pulley is subject to this kind of damage due to harmonics not to mention general water and grim. Remember most of the engine components on your motor were designed to last only 100K miles. The fact that we all get 2x that and more is a bonus. Everything I own has 150K to 300K miles on it so I have no expectations. I use a liquid wrench penetrating oil on everything I disassemble. And yes I break stuff all the time. Good luck on your next project.

Blobbo

Ford mechanic said it was tight because they put Loctite on everything but I'm not buying that. Every other bolt came out just fine. Sometimes you win, sometimes you lose. The shop ended up drilling out the bolt and inserting a helicoil.