tranny mount.

 

I get this too I think, but I wouldn't call it a rattle as much as a growl. It can be heard in the lowest 4 gears, when applying throttle from 1300 or less RPM.
I have the car 2 years and it's always sounded like that.

I've read a few threads claiming it's normal -providing you have the "Growl" and not a rattle.
http://web.camaross.com/forums/showthread.php?t=183091

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My M6 makes the same sort of noises. It kind of bugs me but I always just figured that it was normal for the car. It rattles a bit in low rpms and when the clutch is engages in neutral just like yours. My guess is that it is probably just the tranny design and not an issue, but if someone finds out different, PLEASE POST!

 

I would have figured it was normal too...but I test drove a 95 z28 in Atlanta, and it didnt make the sound. Granted it was in better condition than mine...but the mileage sucked (157k+). But yea it didnt make any sounds.

 

Growl does seem to fit more I guess...its a fairly high pitched 'growl', thats why I called it a rattle. I'll still look at the shield and the cats, but if its so common I can live with it. Can it be heard outside the car tho?

 

It is driving me crazy that so many people report this exact same problem, I call it the rattle chatter at low rpm, mainly when lightly accelerating in first or second, and NObody here has any clue what is causing it. So far, the crumbling catalytic converter theory seems to make the most sense to me, but I would have to think the sound would occasionally be heard at other times, like when shifting into 3rd or 4th at low RPM. I don't know why this is just a first second gear thing. If it's a bad clutch, I can't understand why the clutch works fine in all the other gears and shows no hint of slippage. This is so annoying.

 

it is certainly not the "crumbling catalytic converters" because if you take out your cats, it is still there It has got to be something in the transmisson, unfortunately.

 

Mine does it in the first 3 gears at low RPM when loaded, but it sounds fine when it's not loaded up. If i mis-shift or need to accelerate and don't have the time to shift, it rattles/chatters. Still hasn't fallen apart!!

 

talk about reviving the dead lol. Its not the cat converters, I don't have any. It only occurs at slow acceleration in 1st gear for me, and occasionally if I dip below 1200 rpm in 2nd-5th (6th doesnt do it and I'm guessing 1200 as when I shift I dont drop below 1500 and at idle and speed my tach is about 300 off...) Its really not a big deal...the thing that really drives me nuts now is my dying clutch and the damned spare tire that doesn't want to stay tight on its mount.

 

It's just a little gear chatter. T-56s have pretty beefy internals for what it is.

Every M6 LT1 i've ever driven made that noise at very low rpm, including mine when I swapped an M6 in a couple years ago. It's getting a rebuild right now but there's no evidence to suggest something was wrong with it. Sometimes the throw out bearing is the cause, but even then unless it's REALLY loud there's nothing wrong with it.

It's just the price you gotta pay for having a strong tranny.

 

I have good news about that low rpm tranny chatter-growl....After staring at the underside of my car for 3 hours this morning and hitting everything with a rubber mallet to search for the mysterious cause of the chattering sound, I happened upon the heat shielding just below the passenger side floorpan and above the exhaust pipes (both pipes run below the passenger side). Although all the bolts were tight on the heat shielding, it rattled and reverbed like an SOB. It vibrated really bad when I hit the tranny mount. So I stuffed some dense rubber (hopefully it won't get too hot) to stop the rattle and bent some shielding around so as to limit the metal to metal contact. I took my car out for a test. Unfortunately, the chatter was still there. But I'm sure this heat shielding is causing a problem for a lot of people here. So back to the problem. Inside my car, I removed my center console, shift boot, and rubber tranny cover so that I might hear the noise better when test driving. The chatter could be heard more clearly now. It was definately something in the tranny. So, I decided to take my car to the shops. I went to 3 different transmission shops: American Transmissions, USA Transmissions, and Westland Precision Transmissions (SE Michigan). I had 4 different mechanics drive my car. They all heard the sound. They told me not to worry about the tranny chatter at low rpms, ..."it's just the nature of the beast" is what one mechanic said when explaining the issue. 3 of the mechanics came up with the same conclusion. They said that it was just typical chatter from the synchros or sliders in the tranny. The first mechanic just didn't have an answer. I asked why other camaros don't make the sound? He said they probably do, but it might be chattering at a lower pitch and be lost in the engine rumble. One mechanic said he could adjust the syncros and sliders ( I don't know if those are the same things) so that there was less play and chatter, but it would probably make it harder to row into the gears. All mechanics agreed that it was nothing to be concerned about. Again, these were mechanics from 3 different shops. During testing, I did not tell any mechanic what the previous mechanics concluded. I didn't want other mechanics to influence them. I still don't like the fact that the car makes this chatter, but I feel better after talking to the mechanics. I'm sure if there was something that needed to be fixed they would be jumping all over my wallet and the opportunity to service my transmission, but they all said there wasn't anything to fix.

 

This thread got me thinking. So I went outside and made a quick video. Compare my rattle to the ones that you are complaining about. shriekingtires, I think that you are right. I always thought it was my exhast rattling up against that crossmember undernieth the car. Never thought about the heat shield. Let me know.

http://videos.camaroz28.com/video/f3...2801461fb9.htm

 

The low RPM growl is the 6 speed transmission period. At low RPM's (clutch fully releasded) under a load the power transfer efficiency through gears is decreased and more unstable. Once you reach around 1.5K every just smooths out and the noise vanishes. The easiest way to reproduce it is to drive in 2nd at around 1000 RPM or even lower.

Obviously this does not happen on a new tranny and I am speculating that it can be traced to bearing wear on the lay-shaft's or the main shafts. Again when you factor in the decreased power transfer efficiency with some slightly worn parts you get the noise. I'm not sure the noise can be traced to the syncros, but I am not a transmission guru.

The good news is it is really harmless and just annoying. Adjusting your take off with a slightly higher RPM almost eliminates the noise. I certainly would not rebuild the tranny for just this, however if you have to replace the syncros I would look for some additional worn parts.

Another thing that seems to make the noise louder is aftermarket shifters cause they are not sound dampened like the stocker. Don't believe me rest your hand on your shifter under any driving condition and the normal tranny noise is amplified.

There is no way of fixing it without a full rebuild.

 

The Video from Eddie Z was great. My computer audio system sucks, but from what I can hear, the chatter sounds similiar to mine, just slightly deeper in pitch. Thanks for the vid.