5.7 hemi got loud all of a sudden.. fixed.

[A-TEAM]

So yesterday I started my truck and it seemed way louder than normal. Walking around the outside it seemed exhaust related. Crawled under there today to inspect and sure enough I found a broken flange bolt. Was on the second downstream flange. It was hard to spot because both parts of the bolt were still rusted on the flange but it was definitely broken. Had to move it around with a light on it to spot it. Had to drill out the threaded part of the old bolt because it was seized in there. Ended up fixing it with an hour and $1 in parts. Grade 10.9 bolt, washers and nut. Just a heads up if your hemi is sounding loud lately check the flanges!

 

[Eighty]

Is that a zinc-plated bolt? I thought zinc would cook off at the temperatures that are reached in exhaust systems.

 

[PurpleRT]

Probably should of replaced the other bolt too while you’re there.


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[Av1]

Is that a zinc-plated bolt? I thought zinc would cook off at the temperatures that are reached in exhaust systems.

It looks like cadmium plated in the photo to me. I would use stainless hardware, if it were me.

 

[A-TEAM]

Its a grade 10.9 bolt i got from autozone in an automotive kit, had it on hand already so in it went. I actually did think about doing the other one but its still solid so im not going to disturb it. Ive fixed too many things that aren’t broken and paid the price. Leaving on a 500 mile trip in a few days. If it breaks again I’ll probably put in another bolt and lay down a bead of weld on the flanges. Its hard to keep the salt off a truck in the rust belt.

 

[A-TEAM]

A photo of what I used, and I he next step after the rest of the system melts away 45k miles for reference.