So I first noticed this problem maybe a month ago but the past week or so it has gotten a loot louder. Basically whenever I am moving backwards, whether that be in Reverse or just rolling down my driveway (NOT in gear) I hear this loud noise that sounds like something is rubbing, almost a higher pitched squeak.. but still a rub... It's not 100% of the time, and sometimes it's louder/longer and sometimes it's a half second noise that goes away.

I did just put in a new clutch and lightweight flywheel, but I don't think this has anything to do with it because the noise was happening before. I put it on a jack and looked around, rotated tires backwards (not doing much bc rwd). I didn't see anything out of wack.

I didn't get a chance to check the driveshaft for play, but I did grab tires and check for wheel bearing (12-6) and ball joints (3-9?).. none that I could tell. I know its nearly impossible without hearing the noise, but does anybody have any suggestions before I take it somewhere to put their filthy hands all over it?

EDIT: Its a 2003 5-speed with 90K or so

 

Post a video of the sound, if possible

 

I'll try and grab a video of the sound after lunch today. Obviously it's a shot in the dark, but I read a few things (not 350z specific) that mentioned could be something with the brakes.. either a loose/sheared bolt on the caliper (no idea how that would be sheared) and also somebody reported their e-brake assembly got 'loose' and when moving backwards it shifts to rub... Random stuff, but I'll be tearing into it later tonight to check both of these in the rear.