This is for my friend's car. It is a X GSR & as far as suspension & brake mods go, he only has a set of Tanabe springs & a set of Brakeman brake pads, which were put on this spring.

So, I went on a mountain drive with him this weekend & we heard a very odd sound, which we think is coming from the rear passenger area. The trunk was emptied of all liner, spare tire, floor boards & it still made the sound. We checked the bolts holding in the strut towers & shook the various items (reservoirs, battery, sub, etc) & nothing appeared loose in the trunk.

The sound definitely appears to be metal on metal & sounds like if you released some nuts in the trunk & had them getting thrown about in the spare tire well. After that it sounds like, a mini jack-hammer. & if "mini jack-hammer" isn't a good description, it also sounds similar to lets say the nut on the bolt that holds in the struts in the back were rapidly lifting up & slamming down. But that is not the case of what is actually happening (we checked).

He took it to the dealer & the mechanic kept saying that it might be the brake pads. Could the brake pads really be making such a sound? I find that hard to believe, but I could be wrong (hey, it happens ). The mechanic also supposedly checked the end links on the rear sway & shook other items around underneath, to see if anything was loose.

If anyone can help, it would be much appreciated.

http://www.youtube.com/watch?v=wZ_nU...layer_embedded

http://www.youtube.com/watch?v=iQk4x...layer_embedded

 

I'll go right to worst case - Rear differential? The videos don't have the greatest sound, but to me, that sounds like some metal parts rattling around inside a housing. Since you say it's from the rear, that eliminates the transmission and leaves the differential.

I can't think of any way for brake pads to make a sound like that. Does it only happen under braking? If not, they're out. Only with lateral loads? Look at suspension parts. On straights coasting or accelerating? drivetrain, possibly rear suspension (though you'd probably hear this under lateral loads).

Did you check the sway bar end links yourself? Those have been loose on a number of Xs, including my own. Mine didn't sound anything like that, though. It really sounds like something rattling around, and if there's nothing in the trunk then...

 

Thanks for the reply. We did not check anything ourselves, except objects that could be rattling in the trunk. It would happen during left-hand turns, so he should not have been braking at the time.

What could cause rear diff issues? I believe the dealer said that the front tires were a bit more worn than the rears, but he's maybe gone 3k miles max, since his last tire rotation. They did not specify as to how great the tread depth difference was.

 

Well, this could cause diff issues. Of course, it depends on just how different the fronts and rears are, but any time you have tires of different sizes you could cause trouble.

Sounds like he needs to rotate more often than 3k.

In any case, if it's only when turning it's probably suspension related. You can't eliminate the drive train since it'll be moving torque around between the wheels during a turn, but I'd start with the suspension pieces.

 

Sounds like you might have been right. My friend posted this on Evo X Forums:

 

I'm not terribly surprised, but I am happy it was solved by simply rotating the tires. That was truly a best case situation. Crisis averted!