B&B to Cat connection

What on earth is causing the bolts to fail?

CTSV_510 said:

What on earth is causing the bolts to fail?

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Word.

I would say that an exhaust hanger would break before a bolt would.

And daymn, how bad are your mounts to let your engine have that much movement?

I'm assuming the lateral movement of the motor is causing the bolts to snap. The fact that the connection between stock cats and B&B is never flush probably contributes to the issue? Ive seen old posts where people had same bolt issue. Their is no exhaust hanger around the cat to B&B connection. According to my dealer the MM's are fine. They don't look to be cracked/leaking, but I get some nice dieseling on shutdown, but still denied! Are others with B&B 3" catback not running into this issue? Maybe I should try another exhaust shop if thats the case. The optimal solution would be new B&B headers w. cats, but thats not happening this year

what do you expect when you spend that kind of money?

814V said:

what do you expect when you spend that kind of money?

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huh?

I would venture to say your motor mounts are toast.

There should not be enough play to snap a bolt, let alone several.

As for a seal, sounds like you got stuff slippin and sliding enough to break a seal and a bolt.

I would not cut flanges off the headers though as you are gonna have major hacksaw work if you have to disconnect stuff.

I also assume that isn't going to fix your problem and your gonna start breaking welds.

No troubles with mine before I put the Headers in or after.

1- Are they tightening down the bolts too tight?
2- What Grade bolts are they using?

Dieseling huh? That seems a bit strange, I don't think my V has ever done that.

Not sure what 814V means either.

Heckling will get you a vacation.

Use sarcasm, it's easier to hide.

heavymetals said:

Heckling will get you a vacation.

Use sarcasm, it's easier to hide.

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I, for one, could use a vacation! All expenses paid?

Are the center supports installed? They connect the resonator or X-pipe to the body and are rubber with threaded rod sticking out both ends. These support the center of the exhaust and also allow some movement. Sounds to me like yours is hard mounted to the body cause some sort of fatigue failure at the connections.

stinkpalm said:

huh?

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it was supposed to be a joke.. not a very good one

I'm using the factory GM Cat to exhaust studs. I agree, it must be my motor mounts, but the dealer doesn't agree with me (GMPP extended warranty)...so I'm stuck until the MMs start leaking I guess :helpless:

The welds would be done at the point between the catalytic converter and the first section of the B&B, so I figure if need be the system could still be dropped down by unbolting cats from headers and then 1st B&B section, and I was wondering if anyone else around here had done the same weld. I have the center x-pipe mounted with the rubber bushings and hardware, its snapping off by the cats.

Im hoping maybe the bolts were installed to tight, but now the dang cat flanges need to have a bolt each drilled out!

Well first of all, your bolting a 2.5" flange to a 3" flange.

Did you remove the "doughnuts" from the stock headers so they don"t shift around?

I would offer you up a pair of the solid copper gaskets I had made up for sealing this type of joint, but I don't think that is gonna fix your problem

heavymetals said:

Well first of all, your bolting a 2.5" flange to a 3" flange.

Did you remove the "doughnuts" from the stock headers so they don"t shift around?

I would offer you up a pair of the solid copper gaskets I had made up for sealing this type of joint, but I don't think that is gonna fix your problem

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heavy's solid copper gaskets are the bees knees...

Thanks Heavy, I'm not sure if the exhaust guys took out the donuts out of the cats, so that may be part of the problem? I thought you were supposed to leave the donuts in? I would check it myself but currently have a broken hand, but it sounds like this isn't as prevalent an issue as I thought it was. I'm sure the MMs are leading to this, but I'm still tempted to weld the cats to the B&B as the ultimate solution...since I don't have the $ for B&B headers right now.

Hung my B&B catback to the factory cats over 3 yrs ago with new donut gaskets.
Never been any issues with broken bolts... or anything else.

OldRoadDawg said:

Hung my B&B catback to the factory cats over 3 yrs ago with new donut gaskets.
Never been any issues with broken bolts... or anything else.

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With the flange on the stock headers, you shouldn't have problems. With the B&B headers, you need a good connection...

thebigjimsho said:

With the flange on the stock headers, you shouldn't have problems. With the B&B headers, you need a good connection...

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Well big guy.... those B&B headers just happen to be sitting on my workbench.
(I believe it was you that suggested checking a certain e-bay site :highfive
First some Jet-Hot coating, then install.
Gotta do a 'search' for what is considered the 'beesknees' in gaskets.

Thanks for the replies, esp. OldRoadDawg! Good to know others haven't had this issue, looks like I will just head over to another exhaust shop...anyone have suggestions for a good shop in Austin, Tx? It also sounds like I should pick up some new donut gaskets as well. I wish my hand wasn't busted, bc I should have just installed the system myself in the first place!