Broken bolt ID
 

Greetings all;
Found two identical broken bolts lying next to my truck in two different (map) locations.
Haven't been able to see anything underneath. I'm hoping one of you might recognize it.

Truck is a 2017 XLT 4WD 4DOOR. Thanks...
https://cimg7.ibsrv.net/gimg/www.f15...dad7293f3c.jpg

Found it
 

Took 10 guys at the dealer... Tow hitch bolts. Could have been a disaster since I tow a 32' travel trailer.
They think they were overtightened at the factory.. Beware..
Last time I towed was in November. Can't figure how they fell off now. They will be replaced under warranty however I think I will put in stronger after market bolts.
https://cimg7.ibsrv.net/gimg/www.f15...9e0e27cf88.jpg
https://cimg8.ibsrv.net/gimg/www.f15...c04f374508.jpg

Scary, what are those, 3/8" grade 8?

Looking at that bolt it appears it was a defect to begin with, notice the rust on certain portions. It probably cracked when installed, heat treatment went south. They use pre calibrated tools when building the truck on the line so I doubt they over torqued it.

Looks like a metric 10 series, 10.9 I expect. That's what the bolt heads should say. Might want to make sure the bolts match the nuts. Someone may have subbed in a lesser grade at some point.

10.9's aren't that much stronger #8 farm bolt you find at tractor supply ..or what not.

Everything is going to be metric. The only place you will find SAE 3/8 is a muffler clamp.

True, stuck in the olde world. 3/8" is pretty close to 10mm.:D

Aftermarket fasteners are NOT stronger than OE or service replacements.

I'd be curious about the weight of this 32' TT (gross & tongue), and whether it was ever dragged through a pothole, or backed into something, or the LDH was set wrong.

I just slid under my '13 and it has a similar arrangement, 3 bolts per side. They are 12 mm/10.9 so a pretty stout bolt. Looking at the picture, I'd say those are 12's also.

Guessing roughly 7500 dry with tongue at 10 % plus. Some of those LDH's aren't the greatest, don't fit correctly. The propane pan can get in the way. I've seen a few where they decided not to move the pan and fudged the LDH instead....not good. Could be anything like that.