This past weekend I lowered my Mustang with my Ford racing B springs, everything went well but now I have a rattling in the right rear. I re-tightened everything and it still is there it sounds like it is a non-load bearing rattle, in other words it appears to be fairly lose but it is bugging the tihs out of me, any ideas what it may be?
Cheers
Cooper

 

Could be your exhaust rubbing somewhere.

 

I'd bet it's the exhaust. You have to check it on a rack (with the weight of the car on the tires). Check where it goes over the rearend and where it goes by the gas tank. You can losen the bolts and tweak it or you can take a hammer to the offending spot

 

My exhaust rattled against one of the bottom fender area right above the rear axle.

 

Guys, I appreciate your responses thus far but if you see my sig, my exhaust is dumped before the axle, so it is completley free of the suspension components. So any other ideas?
Cheers
Cooper

 

here's an idea... get down under the car and smack it with a hammer... when you hear the rattle, you've done found it.

If you disconnected the catback to install the rear springs, then chances are you did like I did and left a friggin socket inside your frame rail. I found it eventually and removed my 21mm socket from the frame rail. Rattle stopped.

Even with dumps, you can have exhaust rattle... the muffler can rattle against the frame rails with only a small misalignment. Don't discount it until you check it out.

Also, since you're using flowmasters you may have had one of the baffles inside break a weld and it's rattling. I've had that problem.

From experience, flowmasters dumped sound incredible on the outside but they flat azz hurt inside the car. I'd recommend getting something like a real muffler before your flows... short (12") cherry bombs work well to take some of the interior resonance out while keeping your sound nice and loud. If your car is anything like mine was with dumped flows, around 1800rpm will shake your nuts loose with the resonance.