Exhaust bolt question (backed themselves off?)

Replaced the stock pipes with BAM about 35k miles ago.

Last weekend, the exhaust seemed loud and I heard a sound like birds fighting under the truck while driving. Or really loud, ‘roided out crickets.

I drove the truck to the coast and back, and the sound was persistent. After, I got under the truck and looked around with the engine running, and found that the exhaust flange bolts were ALL loose.

I started tightening them back up, and found one that was significantly tough, and once out, I saw that it was cross threaded.

The flange it threads into is sturdy threaded steel, and I got the bolt back in and very tight, and tightened all the others as well.

Do you guys find that these bolts back themselves out? Or should I be concerned someone was maybe trying to steal my BAM exhaust?

 

Mine have not moved, over a year installed.

 

Thoughts on this? @17TundraDCEd

 

I've never had them loosen up on me. I certainly hope nobody was trying to steal the system..... If the bolts are in good shape (OP mentioned one being cross-threaded) could always try a little threadlocker BLUE on each bolt. Or just replace the bolts for piece of mind - they're usually only a buck or so a piece through Toyota. Good luck to OP - hopefully just a fluke.

 

I have changed my catback exhaust on my previous 5 vehicles and nerver had a bolt lossen up on me on its own. Hopefully this was just a user error. Make sure you tighten them up to spec.

 

I usually find it near impossible to back the bolts out, even when I want them out.

 

Loctite isn't going to do much on exhaust system bolts. Heat is how you break the bond loctite provides. Either double nut or find the nuts that have one side more oval than round. Can't think of the proper name but some lock nuts have the nylon inserts and these don't work, some have pressed indentions on the flats and some nuts are slightly deformed so the bind on the bolt threads. You want the last two types.

 

https://www.lok-mor.com/products/prevailing-torque/o-loc/

 

Thank you.

 

When I had my first 8" years ago, this happened to me.
I just retightened them and they never came loose again..

 

Thanks all!

 

The last clamp on mine came loose this weekend. The resonator would hit my truck bed every time I hit a bump. I just tightened it back up. Hopefully it will stay tight