Ive been having trouble keeping one of my mufflers from vibrating loose.... Whats a quality high temperature thread locker

What engine? Prop balanced? Mounts tight? Using lock washers? Red thread lock is strongest, blue mediam, green light.

I just use silicone sealer for a "gasket" on my mufflers, and Loctite 242 "blue" on the bolts. No problems....

AV8TOR

its my brothers engine...32x10 Xoar laminated(balanced) 3w 157...No lock washers, and its come loose on the same side twice.....

I my self havent had any problems lately, since i started using the red thread locker in a blue tube that Autozone sells... He has tried it, no luck

There's a Permatex Hi Temp Red RTV Silicone Gasket Maker in a tube. I've got an o-ring missing on the header for a Slimline muffler and I can't get them to respond, so Ima gonna give it a try.

Regards
Michael

You stated one of the bolts were coming loose,not loosing seal. Has the bolt stripped out the threads? Sometimes it will seem like the bolt is tight, but there are not enough threads to hold it. Thread lock will not cure stripped threads.

Inside star lock washers should help. Dan.

hmm im not sure it is stripped... its a possibility, since it has happened twice on the same side..

I gave up on locktite. I drill the bolts and safety wire them.

I use the high temp silicone stuff on mine and haven't had an issue but one of the things I do is to make sure I give the exhaust bolts a tweak right after the first run when the muffs are re-installed with the engine still warm, you usually get a bit more torque on 'em.

One other observation from watching a friend fight this battle with a ZDZ-80RV; once it happens you get about one more chance to get 'em tight or the threads inside the exhaust port get worn from the vibration. They may not feel stripped but if you play around with the one that's having an issue vs. the ones that don't you can feel the difference.

IMHO, once you get that extra slop/space in the thread contact area there isn't anything that's gonna stop 'em from coming out again except safety wire and that's not an option on a number of muffler installs. My buddy had to put heli coils in his ZDZ to fix the problem and it did work.

Cool.

Loc-tite makes a green formula thats called "Sleeve & Bearing Retainer" It's pretty much permanent until you take a torch to the bolt and heat it up.

It's designed to lock steel sleeves into aluminum cylinder blocks. We use it on the main caps and rod cap bolts in drag racing engines. It's high heat and extremely high strength. It doesn't come loose until you use a propane torch and heat up the head of the bolts. Heat it up for a few minutes and let it sit to soak the heat into the bolt. You'll probably have to repeat this procedure at least twice before there is enough heat in the bolt and surrounding metal to soften the loc-tite.

I've used it on several mufflers over the years. Works great. The only thing I would caution against is trying to loosen the bolts without first hitting them with the torch. You'll just snap the head off the bolt and then you're really hosed. It IS permanent and you WILL NOT get the bolts out without a torch to soften the stuff up first.

I don't use it anymore though. I drill the bolts and use safety wire now. It works good and it comes off a lot easier when you're ready to take the bolts out.

i have used Align blue one and its really amazing. It came with my trex.

Permatex makes a High Temp Red locktite that comes in a blue tube. Do a search on the internet, it can be hard to find. It has a higher temp rating than the green stuff..... I switched to this over the blue and normal red and it solved all my problems. Be sure to clean the threads on the bolts AND in the cylinder good with alcohol to get all the oil residue out of there.