Hello,

This sound can only be heard inside the car with the door shut, you can not hear the sound from outside of the car. To best decscibe the noise I can call it a popping low tone noise. Sort of what you might hear with a hole in an exhaust pipe. I listened to the sound of the Trannie Flex Steel plates and it is not that sort of sound at all, my sound is much lower in frequency in tone.

I have had it on a lift at (2) muffler shops and there are no leaks to be found.

It makes the sound in neutral as well as in drive and the sound goes away above 1,550 rpm. It is louder when in Drive and accelerating. It is not a new sound at all but trying to isolate it finally.

Is it possible for the Resonator to be bad and if it is bad to only hear it on the inside of the car? ie the sound is projected up to the Floor Pan behind the drivers seat?

The fellow at the muffler shop is perplexed as much as I am.

Any assistance would be much appreciated!

Thanks!

Possible.My 3 mufflers were so full of carbon,so I cut them off,and welded steel in place.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

It's a 1982 300SD w/155K miles on it.

Thats alot of years then for moisture to caused rust inside then.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

I've read allot about mufflers filling up with carbon but then I read that they don't fill up with carbon. Seems 50/50. Anyway to tell without removing exhaust system?

I did listen to the fellow who did the 3" side pipe exhaust and that is way too loud for me, very interesting to say the least. I did get a chuckle out of it!

The guy at muffler shop wants to disconnect the exhaust system at the connection up front behind the Down pipe to see if the noise goes away behind the seat but we are afraid the resulting noise will overwhelm the original noise. Any suggestions?

How much noisier will the car be if I get him to cut out just the Resonators and any suggestions on support of the jumper piece?

One guy yesterday told me I may be missing an exhaust system hanger from the (2) holes on the bottom of the Transmission, but those holes to me don't look like they are supposed to have brackets on them.

They look more like Rigging Holes or repairs at a trannie overhaual shop.

Am I missing a support here?

Thanks!

The resonators do look Original since I see metal stamping inprinted numbers on the. Looks like Mercedes numbers.

Have you looked to ensure that all bell housing bolts are in place and properly torqued? I once owned an 83 SD and had a similar noise...turned out someone had removed the trans. and when reinstalling had apparently not gotten all the bolts tight and two of them were missing.

Good luck.

I had this same question a while back. The response I got was Yes, there is supposed to be an exhaust system hanger attached at the two "holes" on the bottom of the transmission. If it is missing, the exhaust may be moving around. Do you tend to hear this noise when going over uneven surfaces or underway on a smooth highway?

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Sam

84 300SD 350K+ miles ( Blue Belle )

Thanks for last 2 replies,

Bell Housing bolts need to be checked to make sure tight or missing. Check; TY

Yes, I'm missing a bracket from the 2 holes on bottom of trannie, you say. Sam where did you get a bracket?

If this bracket is missing then maybe trannie has been out and like Lawson said maybe a couple of lose bolts or bolts missing.

TY

I hear the noise on any road surface at any speed. I can make the noise get louder by putting on foot brake and slightly giving it fuel to say 1,000 rpm. It will do it out of gear too but not as loud as when in gear. Thanks for help.

I hate to pull resonators off if the problem is elsewhere but I may have to do that eventually, not sure. Thanks for that suggestion also.

I haven't found a bracket for mine yet. Actually, I'm on the lookout for an entire exhaust system, hopefully salvage, as mine has a few butchered repairs. The muffler is shot and is currently "bandaged" with sheet metal and stainless safety wire.

Another thing I found that was causing problems were bent exhaust brackets. When the rubber donuts are installed, the exhaust should be snug against the rubber bumpers. If the exhaust is hanging, slightly loose, the donuts will break constantly.

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Sam

84 300SD 350K+ miles ( Blue Belle )

I looked again at the car and I do have a Cross Two Holed Bracket just below the expansion bellows in the downpipe. The two holes I was preiously referring to are at the extreme "rear" of the transmission not the front.

Hole are like 5/8" or approximate, part of casting of trannie. Is the exhaust system attached to the transmission at both locations or just at the Down Pipe (just below the expansion bellows) at the front. Mine is just attached at the front.

I looked for any missing bolts but I see I need to take off the cross bracket to get a good look at the bottom bolts.

I have a torque wrench, anybody know the torque setting for these bolts on the bell housing?

They look like standard hex heads.

TY

does this happen when parked or moving? if only when moving, you should inspect your driveshaft for interference, check the rubber flanges on the driveshaft and the support bearing on the driveshaft as it is tied directly to the passenger floor at the tunnel.

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1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)

Makes sound in neutral also but not as loud. Maybe 1/4 the sound.

I'm going to check the Torque on Bell Housing bolts once I find the Torque specification; looking around now for it.

You have the 722.3 transmission.

The trick is finding out which bolt you're referring to.

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83 SD

84 CD