Exhausted by Muffler Bolts

[JBuchanan]

Muffler bolts rattled loose. Replaced metric with SAE to "tap" new threads. SAE bolts also rattled loose from (Al?) jug. New jug or re-tap at next larger metric? Thanks!

 

[trboxman]

I'd use permatex gasket maker as thread lock.

 

[JBuchanan]

I'd use permatex gasket maker as thread lock.

Thanks. Temp rating ok, I presume?

 

[trboxman]

Should be. If you're worried about that you could get some thin split ring lock washers to try as well.

 

[JBuchanan]

Thanks again. I should have asked for advice before the SAE attempt - split washers probably would have held the oem bolts.

 

[alexcagle]

I buy extra long helicoils off ebay,chamfer the thread holes and install 266 loctite. They work great.

 

[Little Al]

Thanks again. I should have asked for advice before the SAE attempt - split washers probably would have held the oem bolts.

The blue "goo" for locking Disc brake Caliper bolts, & the in or out spikey shakeproof lock washers should do the job

 

[Ted Jenkins]

There are two sides of this issue. If thread lock is used regardless of the the thread type often some or all of the threads will come out with the bolts. I have a saw that has striped the handle bar mount two times so I went to the next larger SAE thread with split washers. For now this is working well. I ordered a new case if this repair job fails. The saw is almost been completely rebuilt so do not mind spending extra $$ to keep it going. Thanks

 

[ChoppyChoppy]

I have tack welded the bolts to the muffler on a few customer saws that kept loosing muffler bolts. Not sure why, but Loctite and locking washers didn't work.

Has only been Husqvarnas for whatever reason.

 

[bmwpowere36m3]

Would have tried medium or high-strength thread locker before tapping out to SAE... I still use split washers, but I've seen videos indicating their "useless-ness" in prevent vibration-related loosening. So give med or hi-strength thread locker a shot.

 

[BroncoRN]

Replace or add an exhaust gasket to help keep tension on the bolts?

 

[SkipD]

Assuming there's enough stock for the larger hole that's required, HeliCoil repairs are quite often far better than the original threads in aluminum. I had an old 10HP snowblower (Tecumseh Snow-King engine) that frequently had loose muffler bolts. The threads in the aluminum block were galled pretty badly. After installing HeliCoil inserts into the two holes in the block, I was finally able to properly tighten the bolts and they never came loose again.

 

[bmwpowere36m3]

Maybe not add... but a new one uncompressed one would help.

 

[JBuchanan]

Thanks all. This is a Shindaiwa 757 (not Husky). The SAE were not tapped - just ran in - but the Al still loosened enough to set them free. I have heli coil set for the OEM dia/pitch ... hopefully enough meat left.

 

[HuskStihl]

Did you replace the muffler bearing while you were in there?

 

[rwoods]

If your bolt heads are accessible, you can drill them and use safety wire. That is what I do. Ron

 

[row.man]

depending on the bolt installation, look into saftey wire like they use on airplanes,

 

[ray benson]

Bend sheet metal on bolt heads.