Exhaust Repairs 2005 Adventurer 37B (Workhorse)

[Wintermute]

Hello again interweb friends. I have been meaning to do this work for months but kept putting it off. First it was because I couldn't find a shop willing to do the work locally. Next, the shop I did find willing to install the parts wanted my soul in return. Okay, not my soul, but there is no reason to charge so much for this job.


We drove up to Berlin Ohio a couple weeks ago and what was once a minor annoyance, a future thing to be taken care of, became a priority. Somewhere around Cincinnati one of the mufflers decided to explode. Yes, this sounds dramatic. Well, it sort of was. One moment we are driving along and all is normal, there was a loud pop, and suddenly I am driving a stock car instead of an RV!


Time was not on my side, it became a now thing instead of a future thing. I have no idea what comes on these things from the factory, and I do know that the exhaust has been replaced by the previous owner at some point because the hangars have been moved.



Ordered some awesome Magnaflow stainless mufflers and attacked the remains of the old parts with a saw to get them off. They slipped onto the pipe, all that remains is to install some band clamps to hold them in place. I no longer have a welder or I would have finished the job today, and stainless clamps should work well enough.



I'll attach pictures below, and the Makita is there for a scale reference next to that wonderful hole. Can't remark on the performance vs the garbage I removed, but the sound is leaps and bounds better. The radiator fan is louder than the exhaust at idle, which is a new experience for me! Hopefully I can take it out for a spin next week to see how things have improved and I will report back.

[Eagle5]

Hi Wintermute,
Nothing more timely than to mute that exhaust noise before Winter, right? (ha-ha)
Your work looks very good. I like the idea of clamping the mufflers to the exhaust, rather than welding. It is sort of hard to weld stainless to standard steel.
Thanks, Eagle5

[Wintermute]

Well, unfortunately the clamps are not working properly. It is still leaking at the seams regardless of how tight I run them down, so welding them is in my future. Monday afternoon if I can borrow a welder.


It is slowly becoming the camper of Theseus. We've been calling it Murphy lately, because of random things needing attention on each trip we've taken, but I think Theseus is more accurate since I have been replacing so much of the old with new.


The effort has been worth it though! It is so quiet with those new mufflers, almost makes me wish I had done a before/after video.

[Eagle5]

Theseus is a great name for your motorhome.

[Wintermute]

Looks like I get to add to the damage. Went out to pull the manifold and found one of my plug wires had burnt. Also had two cracked plugs, but they came out easily enough. One broken stud to remove and replace. Then I can weld the mufflers. I am actually surprised that the engine wasn't missing and sputtering with two adjacent plugs cracked. Guess they were still firing.



If money were no object then I would be buying a set of long tube headers to replace these manifolds. In my internet search earlier today I saw mentioned that any big block chevy manifolds will fit the 8.1, and there are plenty on evilbay, but they are shorties and probably more likely to burn my wires than the existing manifolds.



Tomorrow I get to buy more parts, and wedge myself back in there to get this job wrapped up. I had an Avalanche 2500 with the same engine and it had a little over 100k when I traded it off. Never did have to replace the manifold gaskets, so I am surprised I am having to do it on the same 8.1 with only 63k on it. I mean, I get it, its two decades old at this point and it is what it is.

[Eagle5]

Motorhome exhaust manifolds get so red-hot, I believe you are better-off keeping the stock cast-iron exhaust manifolds. Of course, they are quieter too.