I recently replaced my clutch with a monster stage 3. It seems to make the problem worse, but i believe that is because it engages so much harder.

The problem is, when shifting i get a banging / clunking noise if the revs arent perfectly matched. To me it sounds like there is slack in the drivetrain someplace, because if i roll along, and allow the revs to come down a few hundred RPM's and i drop the clutch, it will make the bang again.

I'm looking for some clues, or hints on what to check first. Everything i have read about says the pinion bushing on the rear, or possibly a bad U-joint. I'll probably replace the u-joints anyway just because.

Is it possible this is something in the transmission itself? It shifts perfectly, and i just changed the fluid and there were no noticeable signs of wear or failure.

 

Video one: Trans is in neutral, wheels are off the ground. This freeplay happens without the wheels ever moving
http://www.youtube.com/watch?v=dmOdneNDL6U


Video two: Same as above, i rotate it, and then shock stop it with force in the opposite direction.
http://www.youtube.com/watch?v=gAHnq0P_8U4

I think i found my clunk, but what is causing this? I think the rear is shot.

My question about the trans is, i have a bit of axial movement where the splines from the drive shaft enter the trans. Is it normal to have a bit of slop here? I went out and tried to move the driveshaft in my truck, and it's rock solid.

I think i have some major problems here.

 

It's important to note that this play is also there when the car is sitting flat on the ground.

 

I'm having the same problem kinda when I take off sometimes. I get banging. I can't figure it out eithier hope someone responds so we can figure this out

 

I have play in mine as well. If I drive and shift easy I get this clunk between shifts. If I drive it harder not some much. My wife in the car I have to drive nice or she gets pissed at me. I feel that this play and clunk is coming from the transmission. My brothers 2009 C6 vette don't clunk. This is my main turn off of my car right now. By the way I have 25,000 miles on it.

 

.....I forgot to tell you. I too just had my clutch replaced (LS7 w/LS2 flywheel) and the noise and clunky is worse. I thought maybe since the clutch grabs harder than my old slipping clutch it has made it louder. I do drive it hard sometimes. Please let me know what this is if you find out. I will do the same.

 

This is also happening to me. I have LS7/LS2 with only 25k on it and is driven easy. I was under the car today and checked the tranny & rear end fluid; all good. I also have freeplay, which was with the tranny in neutral and e-brake on (no rotation from the wheels). This clunk has been getting progressively worse and I see other threads mention a possible broken/damaged clutch spring.

I think some people on here have yet to diagnose this and share their findings. Can we follow this through to the end for the benefit of all?

 

Same issue here, and for a long time. The driveshaft will rotate a bit by hand and is (maybe) the source of the sound?!? The rear gears are newly installed with no hard driving on them yet, so that shouldn't be the source. I don't know enough about drivetrains to know if that play is normal, or what creates the looseness.

Highly interested in a discussion here.

BobP

PS - videos were removed. Can you put them back??

 

Any updates on this one? My '00 TA M6 has, what seems from the posts, to be the same issue. It's been about a year now - intermittent, seems to be more when I'm cruising along (i.e. not trying to get anywhere at the speed of light) and feels like a clunking under the center of the car. Almost like a boulder hit underneath the car. Generally it's when going from 2nd to 3rd.

Anyone?

 

+6 over here, I have the exact same problem.

 

your problem sounds more like a tranny mount though.

 

i also have the same problem, it makes my car shake when disengaging the clutch and you can hear my exhaust hit the floorboard.

Another thing that I notice is that when in an uphill position I can hear this semi grinding noise, kinda of weird.

 

I also have this problem an would like to know of a fix it sounds like there is some slack in the driveline an when you putting around town if you don't match the rpm's perfectly it will make a little clunk. Like the driveshaft has a little movement what would fix that?

 

I have the same issue. I had the problem and when I replaced it with an LS7 setup it got worse. I have less than 35K on the car and I bought the car brand new.

Has anyone figured this out yet?

 

Subscribing!

I also have the clunk. I had it on my 2000 SS and my current 1999 Trans Am. Both M6 Cars.

Now here is a strange thing...

I use to get a bit of the clunk sound (very same sound) on my old 1998 Trans Am (bought new) and my 1999 vert TA. Both of those cars were A4's!

That leads me to think that it's a mount, driveshaft or rear end problem and not exactly a tranny problem.

The "clunk" and the infamous "squeek squeek" while going over speed bumps are two F-Body quirks that have always bugged me and I could never figure out.

I wonder if people with aftermarket rears have the same problem?

 

I had the problem when I had my stock clutch and rear end and it's worse now with the Moser 12-bolt and LS7 clutch.

 

Hmmm...

So that leaves drive shaft connections,suspension or mounts/cross member?

Has anyone ever noticed the clunk while on a dyno? That way an actual visual might be had of the clunk... Or someone driving along side another?

I have a feeling that it's one of those problems that doesn't show itself unless you are actually driving under load...

 

Its amazing on how common this is. I just replaced my rear end due to broken gears with a 9 inch and now I noticed a major clunking sound while shifting. Its really annoying because if I'm driving at slowly at like 35 in 5th gear...4.11's...and I dont rev match perfectly it makes a really annoying "clunking" sound and the worst part about it is when I have the tranny under a no load condition it kinda jerks me forward and back or when I just let off the gas going from positive load to no load it is extremely noticable that there seems to be slack.

Rebuilt tranny about 50k ago, changed clutch at that time with another stocker. New U-Joints from Napa for the rear end change. Gears were setup by MWC...a little off but definitely not the cause. Slight movement in driveshaft...not up or down just rotational.

 

yup makes it sounds terrible. could it be from loose pilot bearings? i was sure it was from excessive backlash but from the posts above guess not.

 

Yeah I feel you fellas my m6 02 SS just started doing the exact same thing a my car has been down for 2 years and i just got her up and done and now this **** IM fed up lol! I have a 12bolt Moser 3.73 tru trac and I get the clunk when iam stopping and when I excelerate from a deadstop it also makes a loud clunk when I turn ??? Please tranny gurus shed sum light on this topic we are all fed up with this irritating NOISE!!!! LoL BB