Ever heard of this?

[Puk]

I was driving along the other day when my ute started roaring. I was close to the shop that put the muffler on for me about 3 months ago, so i crawled around there and we had a look. The muffler had cut cleanly at a weld about half way along. It wasn't hitting anything, and all the rubber mounts were holding it fine. I know Zooks are rough, but that wouldn't sever it cleanly like that.

The muffler man said that it was most likely caused by harmonics, a certain frequency of sound or vibrations at a certain rev range must be setting up a vibration that caused the problem. To his credit he rewelded it for free, and said that if it happens again i might need a "bellows" installed in the pipe somewhere. (This is basically a section of hose made out of woven metal bands, which acts as a shock absorber).

I was just wondering if anyone had ever heard of this before?

Puk

[Gwagensteve]

Bellows are an excellent idea.

I'd just say it's straight up vibration. I've seen lots of broken exhausts on sierras.

Steve.

[Bazooka]

When I had my system made I used to crack the exhaust right at the flange to the muffler everytime I went offroad. It was welded back up 3 times before a flex joint was put in. Once this was fitted I never had a problem again.

[alien]

mine was made and it was "sleeved" over the muffler and welded... ie: it overlaps... this way, should a weld brake ill get a rattle but not a v8 =)