08 Ltd 4.6 - Replace just front muffler or front muffler all the way back?

[pjw73nh]

08 Ltd 4.6L 130k miles. The FRONT muffler has a hole in it near the rear outlet where the hanger attaches at the seam. It's loud. The REAR muffler (resonator) is literally only 2-3 inches behind the front muffler and welded. If I cut the muffler out (between the muffler and resonator) there will be little if any pipe left to clamp a new muffler in/on.

Currently, the entire system from after the spring loaded cat flange, to the back is welded.

The resonator and tail pipe appears to be in decent shape, though I suspect will need replacing in the next year or two. It's hard to tell without getting the car on a lift.

You can refer to this thread where I recently replaced the cat/muffler donut gasket. Pipe OD is 2.75" Very large. I had a difficult time finding the correct size gasket. Dealer only.

2008 Ltd 4.6L needs muffler side flange from where Y pipe joins.

I am interested in maintaining a quiet ride. Closest to OEM I can get without the expense.

Thoughts, comments, suggestions? Options?

Thanks.

 

[SixPonies]

Full replacement exhaust system from RockAuto, $174.89:

WALKER KIT12465401

 

[pjw73nh]

Full replacement exhaust system from RockAuto, $174.89:

WALKER KIT12465401

Hey Six, thanks for the reply. Yeah, I was thinking about that. My only concern is that the last time I did the donut gasket, I ordered the Walker one and it was not the right size for the car? So that makes me wonder if it was an error on Walkers part, or if the one that comes with this kit will or won't fit. I guess I'll call RockAuto and see if they can measure it for me.

On edit: Well I just looked it up again, and it appears to list the right size now. I'll give it a go. Thanks.

 

[pjw73nh]

So I pulled the trigger and got the walker kit.

I put it in today. It went in ok. Getting the original out was a pain in the @$$. I had put a new donut gasket and spring kit in 8 months ago. It wasn't rusted hardly at all, but the little 'tangs" on the nuts would not hold against the torque of removing the bolts. The tangs broke off the nuts. I ended up sawing the bolts off. Then I had a b17(h of a time getting the old system off. It was welded front to back. I knew that going in to the project. I had to cut it in two places. on either side of the rear axle.

I have a question on the spring bolts. The Ford manual doesn't really show the detail of the springs.

Do the springs go BETWEEN the two flanges ? Or do they go on the OUTSIDE of the muffler side flange ? I put them on the outside and torqued them to 30 ft lbs after the shoulder bottomed out. But the springs are COMPLETELY compressed. Acting like thick washers.

The first pic is how I found the originals back in July. The second pic is the flange as I took it off today. Note the large holes. The new flange holes were not that big. The third pic is how it is now.

Thoughts?

 

[Campnham]

I went with the Gibson 3" stainless cat back. That was a real bear to get installed!!!

 

[Explorer_PL]

PJ -

how does it sound now ?
I want to do same thing on mine, 2 holes on the firs muffler where the hangers are welded like on yours.
I want quiet OEM sound.

 

[Explorer_PL]

And you got the springs right, they need to push the flanges towards each other, not apart.

 

[pjw73nh]

PJ -

how does it sound now ?
I want to do same thing on mine, 2 holes on the firs muffler where the hangers are welded like on yours.
I want quiet OEM sound.

It's much quieter (expected) but I can't tell if it's as quiet as OEM was. It's certainly WAY quieter than it was. I still have the 30-40 second manifold (broken stud) sounds when first starting up. But other than that it's pretty quiet.

I will say though, the items in the kit were supposed to be stainless steel. A magnet sticks to every one of the parts.

 

[pjw73nh]

And you got the springs right, they need to push the flanges towards each other, not apart.

Yeah, I was pretty sure I got them in the right place. It just seems that where they're crushed to capacity and then some, that they are now acting more like big washers than pressure springs.

 

[Explorer_PL]

Is the stock exhaust stainless steel ? Besides the holes by the welds, the entire system looks pretty solid still after 12 years and 263k miles.

 

[rustylugnut]

Bumping this.
Dealing with this same thing on my Mountaineer. Front muffler has a hole in it where the hanger is welded on. I want to restore it to as close to factory sound as I can. It'd be nice to find a factory muffler, but I'm mostly limiting my search to the choices on rockauto.
What's bothering me is that the walker replacement, part 53707, the same one thats pictured in the parts listing above, looks completely different than what's on the Mounty now, which I'm assuming is factory. The one on there now is more of a flat, wide rectangular shape, while the walker replacement is cylindrical.
There's another replacement option on there too, though. AP Exhaust #2599. It isn't pictured.
Anyone have any insight on this? It'd be nice to know the factory supplier.

 

[rustylugnut]

Called AP exhaust and got them to send me some more info on their muffler #2599.

This looks a lot more like the factory one, its at least vaguely the same shape, so I went ahead and bought it. I'd imagine they aren't all red. We'll see how it sounds once its installed.
This is a pic I found of the factory exhaust system. The front muffler is the one in question.

I also went to the dealer and priced a new muffler. They only sell everything from the y-pipe flange back, which is what is pictured above, as a unit. For $575. Yeah, I'll pass on that.

 

[SixPonies]

$575 for OEM from the dealer? You can get a full cat-back Gibson or Magnaflow system for less than that in Amazon or eBay.

 

[rustylugnut]

$575 for OEM from the dealer? You can get a full cat-back Gibson or Magnaflow system for less than that in Amazon or eBay.

That's correct, $575 for the OEM cat-back. I had to chuckle when the parts guy said that. He also said they only had a few left in stock, and it looked like Ford was discontinuing the part.
I just ordered the AP replacement muffler for $100 shipped. Pretty excited to fix the exhaust leak. It sounds like ****.

 

[Explorer_PL]

I just replaced the whole cat back with an aftermarket system few months ago. It was under 300 and was pretty close to the OEM, with 2 mufflers included. Perfect fit, I thought I posted a write up but maybe I did not.

 

[Explorer_PL]

I found my receipt from Rock Auto

The whole kit KIT12465401 was $ 186 plus 60 shipping.

 

[Trainmaster]

I know this is an ancient thread, but did you ever replace the factory muffler with the AP? Did it sound the same? Has it rotted out yet? I'm deciding if I really need the Ford $400 replacement. My experience with Walker stainless aftermarket is that they last 2 years. How'd you make out?

 

[ThunderbirdSport]

Walker stuff is cheap crap. It won't last. Been there, done that.

If your front stuff is good, just throw a catback under there and call it good. You're probably not gonna get an OEM level of quiet though.
You could probably call the tech bunch at magnaflow and have them make you a cat back with a quieter muffler.

FWIW, I put a magnaflow catback on my expedition and while you can tell it's got a little tone, it's not loud at all. On the highway at 70 you can barely hear it unless you romp on it to pass. Even then it's not loud, just..noticeable. Non car enthusiast folks probably wouldn't pay it any mind.

****, just realized that the bulk of this thread is over a year and half old...d'oh.

 

[Trainmaster]

Thanks, Tbird.

 

[96eb96]

I know this is an ancient thread, but did you ever replace the factory muffler with the AP? Did it sound the same? Has it rotted out yet? I'm deciding if I really need the Ford $400 replacement. My experience with Walker stainless aftermarket is that they last 2 years. How'd you make out?

Advance will warranty the muffler for life. I tried a few coats of high temp paint on the pipes and muffler, and high temp RTV on the seams of the muffler. May buy another year or two :lol: