matt_w

Thanks, this sets my mind at ease. I found a few threads on LS1/LT1 boards where people had the same issue, so it must be semi-common.

Sorry guys, I didn't do a good job of explaining this. With the rear end completely out of the car and driveline sticking out of the transmission (which is in gear), I can rotate the driveline probably ~5 or so degrees back and forth before it stops. This ~5 degrees of play is what is causing the clunk. It is very noticeable when driving, as anytime you let off or step on the gas, it "clunks" to re-engage. My question is if anyone else has experienced this or if my transmission is messed up.

Thanks for the reply. I have a ron tyler mount and the differential mount itself is definitely good. The only place with free-play is the T56. I'm fairly certain it's the cause.

I've been noticing a loud clunk when I let off or on the gas while driving. All my rear end components were brand new/refurbished, so I was suspecting it was a backlash issue (I had added a gear driven LSD to my R200). I just pulled the rear end and everything was in spec. Once the rear end was out, I tried rotating the driveline (still sticking out of the T56) with the car in gear, and I believe the clunk noise is coming from there. I get a fair amount of play when rotating it back and forth. Anyone else have a similar issue? This is a newly rebuilt T56 from a reputable source. Is this not an issue in f-bodies because they have better sound deadening?

Which part number of muffler did you install? Some of them are designed for larger engines than others.

I called their help line, and it's from the valve hitting the side of the muffler body. It goes away when warm because the expansion snugs it in there. Apparently if they are installed flat this doesn't happen.

I just installed the Dynomax VT and it had a huge effect, completely eliminated the drone. The one caveat on these is that they need to be installed as close to horizontal (so the oval is laid down) as possible, otherwise the valve will make a large banging sound. Mine is installed at about 45 degrees and it makes a sound when the car first turns on (although I think with the build-up of soot, it is slowly going away). Anyway, this muffler is awesome! I have no resonators/other mufflers or anything and there is no drone.

Hmm, only $100 too....I think I might have to give it a shot.

That's an interesting idea. I think that may also cut back on the amount of difficult fab that has to be done (getting from the ypipe to the collectors was a pain).

http://matt.loadedregister.com/240z/exhaust4.jpg Hoping I can fit them in there somewhere...

Can you give some details on the resonators? What brand, how big are they, etc?

We are both running similar mufflers, but I don't think a new muffler is going to fix the problem. I also have an electric cutout, and the drone is almost as bad running straight headers.

Ok, the ~1900-2300 resonance inside my Z is driving me crazy and making me deaf. The exhaust sounds great outside of the car, but inside is like having a lion roar directly in my ear. My exhaust is currently Sanderson headers dumping to dual 2.5" pipes which join into a single 3" pipe that runs through a Magnaflow out the back. I remember reading on here awhile back from a few people that had the same problem and fixed it using inline resonantors up front, but they didn't give many specifics. I was hoping someone here could point me in a more specific direction of how to fix this. I don't have a lot of areas of straight pipes where I can cut in a resonator.

Just put the new shafts in last night. At full droop they just barely fit into place (which I'm pretty sure is a good thing!). No binding or oddities once it was back down on the ground. Thanks again for getting them fixed Jon! As I was finishing up some random guy drove his Z into my driveway and started talking cars(this is like the 6th time someone has done this to me in the past 2 years). He was impressed with the M2 setup and I pointed him to your website.

What the... they aren't supposed to be polished? Mine were super shiny new looking.