Ok you can read my earlier post as to how I got this car under title "Blown Head Gasket/My First Camaro".......The only problem I can find with this car is the transmission. It seems to ship ok but when u put it in reverse..it makes a loud vibrating/knocking noise....the noise is directly unde the armrest of the console and sounds very close to the body of the car....from looking under the car from the area of the armrest it appears that area is at the end of the transmission where it meets the driveshaft....I mainly only get it in reverse..but have noticed it a little bit when going 30-40 mph on bumpy roads.....more like a rattle ...but when in reverse its constant and gauranteed.....Anybody familiar? I checked fliud level its fine...I was thinking U-joints but I didnt think would be this loud and sounds close to tranny and the reverse thing throws me off. P.S. I got under car and one of the transmission pan bolts was on hand tight!! Yikes....im scared of what im gonna discover.

 

Jack up the car on one side and crawl underneath it. There's a cross member that's sort of in the middle of the car under there. Above it is the exhaust pipe. Push up and down on that a little to see if it'll clank on that cross member. That's your likely source. Had the exact same problem a few weeks ago. If you don't have the means of fixing it properly wad up a couple ***** of tin foil and wedge them between the exhaust pipe and the cross member. Problem solved Ha!Ha! But yeah that's likely the problem. If that's not it the 3.4L V6 has got a screwy two piece drive shaft. When that starts to go it vibrates quite dramtically. You WILL slow down or put the clutch in. The other dead give away is the smell of buring rubber when it happens because there's a rubber bushing in that joint. But from your description though I'd bet on the exhaust pipe clonking on the cross member.

Thanks,

Tom