Ok please read entirely before immediately throwing out your responses:
I have a 03' Evo 8 GSR fully built, brand new trans, stock t-case w/ rs front diff.
My problem/issue is that when cruising I get this annoying metal scraping like noise coming from underneath the car by the E-brake area. As soon as I press on the throttle putting the car under load the noise goes away immediately but again once back to cruising the metal scraping noise comes back and its annoying. it doesnt do it every single time but most of the time if that make sense. Now I have no problem with anyone saying oh its your transfer case as that would be the last thing on my list to actually build, but I am not receiving any death whine, and as speed increase there is no intensifying loudness (whine-howl) since 1. there is no whine present at all and 2. again when pressing on the throttle (under load) the noise goes away instantly. Has anyone had this issue and what was the fix? I want to say its my driveshaft but the play in the driveshaft is actually minimum. But maybe there is something internally going bad etc. I just dont want to build my transfer case and the problem still persists when I couldve bought an aftermarket driveshaft w/ respect to pricing. I also have a twin disc clutch (Power Train technology.. Same developer of the QM clutch).
I will provide a video of the metal scraping noise Im receiving from a video whose trasnfer case is in fact dying but listen carefully to the metal scraping noise, every trasnfer case failing symptom the whine is present and intensifies by speed. I am in no way getting any type of whine which draws the confusion, could I be that unlucky with no whine or is the metal scraping noise most likely coming from the driveshaft as i assumed. all fluids are full, OEM fluids in the transfer case etc. and no plates loose or rubbing against anything... really hoping someone can chime in who had the similar experience and resulted in the problem before I waste money on the wrong thing.

Here is the link to the metal scraping noise that best fits my problem:

 

does it happen when you let off the gas or let it wind down in gear?

 

The noise I just described does not occur during decel, I have a twin disc clutch so I do receive decel noise and its not that (two different sounds if that makes sense)... but this metal scraping noise seems to come on only during cruising under no load. If you watch the link I posted it make that similar scraping noise goes away under load.. but again no transfer case whine noise at all. Im wondering if it could be the pinion gear bolt that is maybe loose and needs preload adjustment.. or is it the driveshaft carrier bearings going to sh***t

 

Drive shaft rubbing exhaust?

 

I wish it was that easy man... think my best approach is to buy or borrow a Go-Pro and see if I can capture the area more closely..

 

It could be that easy. The exhaust rubbing is not an unusual problem. Get the exhaust hot and drive in rain and the exhaust will warp - may move an inch or more when you think there is plenty of clearance. Anyway, easy to check, just look for marks. If dry road when the problem occurred then something else.

Another thing that can make that noise is brakes.

 

Could be one of the carrier bearings... Those bastards can sound pretty ugly when they go.

 

Consider your front wheel bearing unit on passenger side, I had to change mine a few years ago, that sound is very simular plus when I was on the freeway going 60-70 sound would go away.

 

I did that little push/pull test on the front wheels and nothing so I doubt its that.. unless that way of testing is not sufficient enough... But only when cruising (holding the throttle steady) is when this happens but when pressing on the throttle putting the car under load it goes away immediately.. and the noise doesnt occur decelerating either.. So so far im stuck until I figure it out. there were a couple threads with the identical problem but its far old and closed and unresolved lol

 

Found this thread while researching the exact same problem . Same noise . Was wondering if you ever figured out what the issue was?

 

Hi guys,
I have the same noise/problem: did you figured out what was?

 

I got the same issue. I wish he had post the result

 

you sure its not just the clutch rattle?
my qm is really loud when you are doing say 50 and you are on and off the throttle (cruising).
soon as you let off the throttle a little it is a rattle can sound.

its the flywheel harmonics..

 

I solved rebuilding my t case (pinion and crown) and my mechanic also modified exhaust pipe in the section near rear torsion bar because for him the rattling sound came from that place.
now is perfect