I had the M090535 installed. Installation looks great, stock tail pipe still in place. I immediately towed 10k about 450 miles. My ears were almost ringing when I got home. Even unloaded it's resonating badly between 1800 and 2200 rpm.

I know Don Thuren says he has zero drone with the same setup, and this echoes what I've read on multiple forums. I'm looking for some suggestions on how to eliminate the drone (short of replacing the muffler again).

When I'm under the truck at idle the muffler vibrates a bit. I noticed that there's only the one hanger for the system above the rear axle, and the next hanger is up on the downpipe. That's a long section hanging freely. Perhaps this is part of the cause?

My other thought was to cut the tail pipe back and install a tip that points down, but I'd like to avoid cutting off the tail pipe. Believe it or not, I really like the look of the stock tail pipe.

Anyone have any experience or suggestions to share?

 

Its not rubbing any cab-mounts or cross members is it? When I installed mine, the guy screwed up and it was touching a cab mount....LOTS of drone and vibration at low RPM around-town driving. Just had to tweak it a bit and a couple of hangers and it was good....

I'd be willing to bet it has to be the lack of hangers or its rubbing somewhere...others will chime in!

I have NO drone at all with mine...and I've towed over 10k several times...

 

I would think with that much distance your getting a lot of vibration on your exhaust system. My front muffler hanger had to be removed, but my back one is still there. So I have 3 on my whole exhaust system. I would check to see if you can put another hanger somewhere on the muffler. I had them make a long piece of hanger stock and bring it clear to the bottom of the muffler. It does not drone at all.

 

Yeah you need another hanger. I've got one on the downpipe, one in front of the muffler, one behind the muffler, and one on the tailpipe section. It still has a tiny bit of drone, but is much better than before. Don't cut the tailpipe section off unless you want lots of drone and you want it to be a good bit louder. The sound just resonates off the ground. I've had mine "dumped" like that for a few thousand miles now and I recently put the tailpipe section back on. Luckily, I have an aftermarket exhaust so I was able to just bolt mine back on. It wouldn't be so easy with a stock system.

 

I have the 41" Donaldson but the same amount of hangers. I only have very little drone when I get on it w/8K lbs. or more behind me. I'd say get more or BETTER hangers or better location of hangers.

 

My stock system had a hanger on the muffler so we put one on this muffler as well. Zero drone.

 

I have a 51" Donaldson. It is louder.
I put a 6" Hog tip on w/rolled tip. That changed the tone some.
I picked up a new TT this past weekend and was worried it would drone and my butt would be toast from my Wife...Funny thing is, it was actually quieter?????
Kat is still in place 2

 

I changed my system around because the drone caused me to practically have to yell for my wife to hear me.

Beyond the above, one the of tips from the old days I recall is to strap some heavy weights on the top of the tailpipe section with SS hose clamps. I think this was a V8-460 Ford tsb from the 1980's.

 

I was under a F250 gasser at work the other day. They used a weight with a rubber isolator at the y-pipe going into the cat. I'm assuming to cut down on resonance. I'm selling the truck, maybe I should grind it off and mount it on my truck???

I took another look at the install. It's an awesome job. He actually reused all the stock hanger mounts with custom-hangers and the factory rubbers. The muffler still vibrates at idle.

I'll try some weight somewhere inconspicuously. Hopefully it will cut down on drone some. Next I'll get some dynamat and place underneath the bed. If at all possible I don't want to hack up the exhaust again...

 

When mine was installed it started to drone sometimes. Took it in and in about a half an hour the shop guy found it was just touching a cab bolt on the top of the muffler. Might be worth taking a look.

 

I used a 4" glasspack from www.completeexhaust.com ahead of my 51" nelson and it stopped the drone. Craig

 

I can't imagine it's a true "drone". Mine will really get DEEP if I lug it, but I wouldn't call it a drone. I've had hot-rods in the past that would resonate my brain in my skull but mine does not do that.

I still love my exhaust and wouldn't change a THING, which I can honestly say is the first time ever with any of the 15-20 cars/trucks I've owned..

Not too loud, not too quiet, no drone, clean and crisp..

 

I'll have to come down for a visit one of these days to see what's different...

I also hope some of the wind noise will go away once the muffler soots up a bit. Right now it doesn't sound all that good with the windows down.

 

I think mine did clean up a bit sound wise, but at the same time, I'm not expecting my CTD to purr like a 500hp high duration cammed gasser haha!

I think the higher pitch sounds from my muffler have softened, and they have just been converted to a deeper tone with about 15k of soot..

 

The guys who put mine on have 4 or 5 hangers on the system.