Need to Replace Muffler

2007 was first year for Cummins using the Diesel Particulate Filter (DPF) which is part of the muffler assembly. Maybe the coach has 2006 engine which would have a standard muffler.

If it is the DPF muffler, a replacement is about $2,600 - $3,000.

I went to Newmar and they sent me an exact fit as was the original.

The big expense here are the muffler, clamps and hangars. For what a muffler shop charges for labor I would rather let them do it, it's not worth my while laying under a vehicle all afternoon with a hack saw and a hammer getting dirt in my eyes and skinning my knuckles. Been there, done that. Just my $.02cdn.

It's more than likely a Donaldson muffler. You need the outside dimensions, inlet/outlet sizes and offset to find the correct part. After that it's pretty easy to replace.
BTW, it's a "Cummins".

Well you know what engine is on the coach. If you are handy you can get one at autozone and put it on yourself. If you are not, then almost any muffler shop should be able to help you especially if the muffler is far off the ground.

DANO2014 wrote:
Friends Coach Travel Supreme 2007, 500HP
Cummings Engine with rusted Muffler.
Any suggestions where to purchase one...
Living in Lafayette La.
Thanks for your help DANO !

Well,
You have a couple ways to handle this. One, find out what the original one was/is and, find the part number for it to see if it's possibly available. The second way is, the way I did it when I recently replaced mine on our '04 Itasca Horizon 36GD with the C-7 330HP CAT. And this is how I did it. You'll need to take a full set of measurements.

1. Inlet size
2. Outlet size
3. Body diameter
4. Body length
5. Overall length

And, is there any angles to that part of the system? That is, do you have an inlet that enters the muffler at a 90 degree angle? If so, where is the center line of that entrance, in relation to the closest end of the body?

Once you have all the measurements, then get a hold of "Donaldson Muffler". They are one of the largest suppliers of Truck mufflers on the planet. I had one of those lousy Aero 5050XL Stainless Steel straight through mufflers on for a while. Too noisy and, it did ZERO for performance, fuel mileage and anything else that it was claimed to improve. So, when it came time to replace that one, I hit up Donaldson.
I brought up an online catalog and started streaming through it. I came up with what I thought would be a good replacement muffler. I then got a hold of a rep from Donaldson on the phone. He and I spoke for quite a while. He was outstanding in trying to work with me, my coach and, my engine. He was calculating total flow, total noise, restriction etc., all matched to the output of my C-7.

He suggested about 3 more plus the one I came up with. I ended up getting one of the ones he suggested. The factory muffler for my coach is a seriously priced muffler. The one I recently purchased from a Donaldson supplier near me, a whopping $76.00!!!!!!!!!

Man was I ecstatic about that!!! Not only that but, through some faniggling, it was delivered to my door step. How about that!!

I did the install since it was there was not very much alteration at all.
Anyway, there's a couple of suggestions for you.
Scott