Vibration under hard throttle

**BMJ99Z28** · 07-10-2008, 05:28 PM

ok i finaly got my y pipe fixed and now whenever i get on it in 1st, when the ass end squats there is a slight knock .I have a magnaflow cat back and i tried to recreate the sound in my driveway by putting weight on the rear end. but it seems to only do it while driving could my rear end be moving under acceleration and the torque am hitting my pipe oh yeah seems to be happening around 2500 to 3500 rpms

**Sweet Chops** · 07-23-2008, 11:24 PM

So is the noise coming from under you or behind you?

**BMJ99Z28** · 07-25-2008, 08:46 AM

the noise is comming from behind me the exhaust is not hitting anything I also can hear a popping sound when i turn right i think it might be comming from my rear end changed the dope the gears look good though

**0verkill** · 07-25-2008, 09:23 AM

do you have any after markes susp. mods?

**BMJ99Z28** · 07-25-2008, 05:56 PM

no aftermarket suspension all stock

**Sweet Chops** · 07-28-2008, 03:11 PM

I think it might be your limited slip locking up or unlocking. The reason I say that is in winter I hear kind of the same noise in my 04 sierra when I slide around a corner in the snow. The noise has been there since the truck was new, i'm not to worried about it. Just a thought hope this helps.

Ryan

**vance-53** · 07-28-2008, 03:43 PM

I had the same problem when I put a new 3 inch y-pipe from slp on my old 99 trans am. the noise sounded like it was from rear but it was actually @ drivers side floor from motor tourqing hard on take off. I was stretching out drivers side motor mounts.. Had to chian motor. The way to test is to put car on asphalt and hold strain on brakes while slowly accelerating, if you can hold car from moving it should make noise.

**BMJ99Z28** · 07-28-2008, 07:23 PM

Thanks guys I was kinda leaning towards the limited slip because it dose it more when making turns. Stretching motor mounts ? what all did you have done to your TA