Muffler and pipe work – Aug. ’17
Six or seven months ago, I was entering the roadway while exiting from a gas station and the drop was apparently too steep for my RV, so the chrome tail piece scrapped off without me noticing until 200 or so miles later. All that was left sticking out was this rotten rusted piece of 5″ tailpipe.
So I spent some time on google last November and found a replacement 5″ chrome tail piece on eBay and carried it around with me while I hoped to happen upon a muffler or welding shop that would work on it for me. I could see that some of the exhaust pipe was badly rusted so my hope was that I’d find a muffler shop with the pipe. There are lots of shops that work on this stuff, it’s just that this is 5″ and many muffler shops I visited only carried 4″ pieces and would have to order 5″. Cummins diesel engines use the 4″, and Cat diesels use the 5″. At least with the RV engines they make. I’ve noticed that even the larger 400-500 HP Cummins use the smaller 4″. Well, whatever, my exhaust system needed some work and now I own a Cat. Personally think that having the 5″ is better for the engine anyway.
Eventually ended up in Burns, Oregon and the Truck Shop in the nearby town of Hines where I stopped to schedule an oil change suggested I call Alan’s Repair…which does do welding and custom jobs on heavy farm equipment so should be able to work on my exhaust.
You can see here that the exhaust pipe around 8″ from the exit has a hole rusted in it and the U clamp is no longer connected to the hanging bracket at all. Damn rust. Notice how the ol’ fashioned leather is still in excellent condition but the metal has rusted through?
So here’s some pictures of the exhaust pipe setup. It doesn’t look too bad, but you can see daylight there just this side of the clamp where there shouldn’t be any. I bought a 12″ piece of 5″ exhaust pipe to cut back a ways so to get past that rotten section of pipe.
Most shops have a problem sourcing this double angle section of pipe that connects directly to the muffler, and most don’t have the bending equipment to fashion it. I’m going to forget getting an exact fit and just buy a flexible 5″ exhaust pipe instead. But I did want to get some way to temporarily attach the chrome tail piece so the hot exhaust gases would be directed away from the front of my toad. While I waited on the appropriate parts. 
As the welding tech worked on it, he found that the there is a rust hole in the pipe near the muffler too so yeah, I do need to replace that 4 foot section of exhaust pipe. But we worked out a temporary plan to kluge it together with that 12″ section of pipe mentioned earlier I’d purchased locally.
Here’s where they had me park. Old fashioned welding shop. Lots of farm equipment around and about.
Welding tech checking out what needs to be done. 
You can see the black soot smudge there where the broken off tailpiece use to be. When in place, it would direct the exhaust down to the ground and away from both the frame of the RV, and the front of the towed car. I’ll be happy when that new piece is back in place to prevent exhaust soot from accumulating on the RV or car. 
Getting the welder all set up. We disconnected the RVs battery grounds and positives. And then made sure to get a good connection for the welding machine’s ground near the work.
Here’s a shot of the entire pipe, the tail piece hasn’t been attached yet. Tech is going to cut it behind that clamp a couple inches, then weld the new piece onto that new end. And attach a new U bolt.
Had to wait for a new saw blade but when it arrived, it made short work of sawing off the rotten piece closest to the end.
Did a couple tack welds and the tailpiece is attached to the previously mentioned new short piece of pipe, that in turn, is welded to the other section. 
They charged me $137 for the work, including new clamps, and I’d previously paid $20 for the short piece of tail pipe. Works out to be around $90/hour. I am happy with what I have as a temporary fix for now.
Next up is finding a shop (or take it back to this shop) to remove that last 4′ portion that is starting to rot out and replace it with the new Flexible 5″ Tailpipe I bought, clamping it to the older sections with these Lap Joint 5″ Clamps. As it was, I left town without getting that done so the parts are currently sitting in a basement compartment of the RV.
I’m not in a hurry with the work because the rotten sections the tech found further back are still small and I tend to avoid wet roads that might accelerate the rusting process. I could easily do the job myself, once I find someone with a reciprocating saw I can borrow.