Over the last two days I have replaced the muffler on a 2010 dodge Grand Caravan with the type that is attached with clamps instead of being welded. These are the u-bolt clamps and not the band style clamps. This is a Walker muffler and resonator. The results so far are mixed.
If I am not stepping on the gas it is very quite. If I accelerate then I hear a sound like I hear when there is a hole in the exhaust. Also, when I first started up the engine some water leaked out at the junction between the exhaust pipe and the muffler. This is the junction between the old exhaust pipe that I didn’t replace and the new pipe on the muffler. I have tightened up the clamps some, but there still seems to be an issue. It is not as loud as when the muffler was split down the side but it is not as I would like it. There was a bit of a burnt rubber smell after driving it on a short errand so I need to check that it’s not touching something it shouldn’t.
I am looking for suggestions as to what to do next.
Should I just keep cranking down on the clamps? I already have then pretty tight and I’m not sure how much further to go.
Should I take it apart, clean up the end of the old pipe better, and put some muffler weld on the old pipe to seal the fitting?
Should I seal it with Permatex 80335 instead of muffler weld?
Should I switch to a band style clamp? If so, which clamp would be recommended?
Some combination of the above?
Should I just wait for the whole thing to rust together?
The muffler is stainless steel and I know that is harder to weld. They would be welding stainless to the aluminized steel on the cat pipe and welding two different metals is another complication. At any rate, I did this myself because the muffler and resonator were $160 shipped plus a $10 fitting and another clamp. Around here it is around $400 to have it done in a shop. Hopefully they wouldn’t charge too much for a bit of a weld but it’s hard to say.
I cranked down on the clamps some more today so thanks for that suggestion. It has improved some. I used a 12" socket handle and then an 18" breaker bar. The nuts were not as tight as I thought they were so possibly there was some loosening from thermal cycling.
Mustangman suggested a stepped band clamp. If I were to switch to that, what dimensions would I use? The muffler is 2.5" ID and the fitting from the cat pipe is 2.5" OD. Can someone recommend a model that would fit?
For now I will keep cranking on the clamps some every day and see if I can get it as quiet as I think it should be. Is there any risk of over tightening the clamps? Is sounds like not but I thought I should ask before I snap one off.
If you want more leverage, get a piece of metal pipe that fits over the 18” breaker bar. I’d go for 36”. I had the opposite problem trying to remove spark plugs on my car about 40 years ago. I used a 4’-5’ aluminum tube to pry out the last stubborn plug. Even then it took a lot of effort with many Lubricating Words.
Sorry for the late replies. Most of the time I am not able to log into this site. I can read the posts but when I click to login it just hangs.
I will look at putting on some extra clamps in the opposite direction but there is not allot of space under there for anything extra. I don’t have this on a lift, so I also don’t have allot of room for a long breaker bar or cheater pipe.
I discovered the source of the burnt rubber smell. I found that the passengers rear wheel speed sensor was sitting on the exhaust pipe where it bends up between the muffler and resonator. The plastic cable shielding was starting to melt. This is a problem I have when a manufacturer describes there part as “direct OE replacement”. This part fits well but the bend over the rear end goes up higher then the original part did and so came in contact with the cable. I added some new plastic cable shielding and electrical tape and was able to zip tie the cable over toward the wheel and up out of the way. I added some mechanics wire as an extra precaution.
I am tempted to take it all apart and add some Permatex 80335 to all of the joints and then add some extra clamps if they will fit. The clamps are only a couple of dollars each.
Given how these clamps work I am not sure that I will be able to get this apart now, especially upside down in the driveway where I have no leverage. Does anyone have an opinion on that? Can I get this apart now or am I stuck with fixes I can do while it is assembled?
I’ve never replaced anything myself diy’ering the exhaust system, but I thought most of the connections use both a clamp & a gasket made w/a special high temp compatible material. Is there a reason why are you not using the gasket method?
+1
And they even have hydraulic and mechanic pipe expanders if you can’t weld it for whatever reason and need to do the slip joint method and the pipes are the same ID or OD… If not already a slip joint type…
On the next day when it isn’t raining I will try to take it apart and put it back together with some Permatex 80335. It can’t hurt to have a sealant in the joints. If I can’t get it apart I will just crank down on the clamps some more. If it is really bothering me I will add some Permatex 80333 to the outside of the leaking seams. That should seal it up until it rusts together. I have some band clamps I can try as well.
