Serpentine tensioner assembly bolt
 

My serpentine belt tensioner assembly mounting bolt sheared off. Luckily it happened while the truck was stopped at idle and I shut it down before damaging the part, belt and other idlers.

Trying to find a new bolt to replace the old one but NO ONE has a listing for this bolt. Even Ford does not have a listing for this bolt. They sell the whole assembly with a new bolt for $170. Napa sells the assembly for $70 but it does not come with the bolt. It is a torx head case hardened bolt and a regular case hardened bolt causes the idler to rub the bolt head. I am searching junk yards but so far no luck.

Anyone have a source for these bolts or a modified bolt that would work in this application?

Thanks for any help.

Don't know if this is the correct one but found it on the sticky above ...

Serpentine Belt Pully Bolt, RH Thread T50
(Napa) 56040

Nope that is the Idler bolt. The bolt that mounts the tensioner assembly to the motor uses the same T50 wrench but is case hardened and 4"-5" long.

I just did the SD double pulley mod, I 'might' be able to find my old tensioner bolt. Let me know if you want me to look for it, I'll mail it to you.

What if you get something like the aftermarket Gates tensioner with the longer arm? Then a standard grade 8 hex head bolt should stay clear of the pulley. 'Course, that's $60-ish, but at least that's less than $170.

I should have one of these laying around someplace as well. Let me know if you don't or cannot find your Glenn, and I will see if I can locate mine.

I will find out this morning if I have had any luck with the salvage yards. If not I would gladly take you up on the offer!

Let us know what you find. I am pretty sure I would be able to locate mine.

No luck on any fronts finding an OEM bolt. It is a M10 X 1.5 thread and I did find a bolt that may work. Couldn't find any "Grade 8" metric bolts but this one is stamped CHS 8.8 on the head. That is Class 8.8 and I am guessing the CHS means Case Hardened Steel. It is a hex head but I think I can keep it from rubbing the idler and will just have to pull the tensioner idler off to install it to the mounting bracket. I have to pull it all apart and take off the mounting bracket to drill out and extract the sheared bolt that is in there.

I will let you know how it goes. If anyone knows that this bolt is not strong enough for my application, let me know. Thanks

IIRC, 8.8 is equivalent to Grade 5, and 10.9 is equivalent to Grade 8. I always get mixed up with an International engine in a '90s vintage Ford truck, what's metric and what's inchy.

If you still want one of the stock bolts, I will look tonight and see if i can find mine. PM me your address if you still need it and I can drop it in the mail tomorrow.

Or, I found mine, let me know if you want it. I'll never need it, Nate or me, doesn't matter.

Thanks guys. I fixed it using a M10 x 1.5 x 100 bolt. I didn't need to modify the bolt length, head or anything. Taking the idler pulley off the tensioner made it easier to install but the bolt can be removed without taking the idler off. There is just enough room so the idler does not hit the bolt head. Drilled out and removed the sheared bolt and replaced both the other idlers on the alternator bracket as they were starting to feel a little rough. All in all it took 1.5 hrs to get everything working again.

It seams that the bolt they used originally is not a Grade 8 bolt. It was easy to drill out, relatively soft. I could not find a Class 10.9 bolt in the 100 length so I used what I could get locally. I will PM you guys if this bolt does not hold up and have you send me the OEM one. Thanks much for the offer!

Good deal. Glad you got it back together.

That is so wierd. My uncles sheared last night when he was idleing next to our shop. Found the head of the bolt right under his truck. Will try your regular bolt in there too If Ford doesn't have one. So glad I found this thread.