Squeak From Exhaust?

[BlancoSilverado]

Hello, 

 

I wanted to find out if anyone else has have this problem? I have a 5.3L 8-speed with DFM, i been having a squeak from underneath the truck, i crawled under the truck this morning and touched the flapper valve and found that it is the main source of the squeak. i will be tying it up later today to hopefully have it stop completely. 

 

Has anyone else have the same issue, assuming some WD-40 will work for a little bit of time until it burns off but I will use some worm gear clamps and a piece of SS. 

 

Thanks, 

[shakenfake]

There was some sort of TSB or fix that was put online on how to fix it permanently but I can't remember what it was.

 

Can't you just cut it out and weld a new piece of pipe in lol

[BlancoSilverado]

1 hour ago, shakenfake said:

There was some sort of TSB or fix that was put online on how to fix it permanently but I can't remember what it was.

 

Can't you just cut it out and weld a new piece of pipe in lol

 Thanks, i will search real quick. 

 

As for cutting it out.  I was thinking about doing a CAT back  or cutting it out, but hearing people have drone issues makes me not want to touch it other then twist it open and leave it there. 

[shakenfake]

Drone differs for everyone. What may drone for you may not be drone for someone else.

 

A cat back if made properly should not drone. It is also dependent on muffler choice. I suggest just get a cat-back as normally you can't go wrong with one.

 

I think the fix is like a band clamp or something I seem to remember

[BlancoSilverado]

Well Damn, 

 

No idea what it might be now. i clamped the flapper valve open and still getting the same squeak. it only happens when the motor/trans/exhaust is fully warmed up (never once cold). Ill try to post an audio file later. 

 

Possibly the expansion joint?

[19 Denali ultimate]

On 10/13/2021 at 1:28 PM, BlancoSilverado said:

 Thanks, i will search real quick. 

 

As for cutting it out.  I was thinking about doing a CAT back  or cutting it out, but hearing people have drone issues makes me not want to touch it other then twist it open and leave it there. 

I had both of mine as well as the stock muffler cut out to replace with a louder muffler and the only real drone to speak of is at lower speeds (below 50kmph) caused my the DFM kicking in.  To avoid this simply put the gear select in manual mode.

[BlancoSilverado]

Found the actual issue, while installing the B&M transmission pan, apparently I bent the passenger side heat shield that is right after the header. I was under the truck with gloves touching everything and had it recreate the sound. One worm gear clamp and we have no more sound. 

 

I clamped the flapper open and my wife was going crazy from the "drone" that was happening, that low rumble was bad for her. Ended up gabbing a jacket and pulling the clamps off the flapper at a gas station.