HI all, my 95 wrx ra has developed a grinding noise coming from the transmission. It started off sounding rotational but now is more a constant grinding, it developed very quickly in the space of about 3 miles and it gets louder with speed.
So after getting it recovered home i jacked it up and checked all the usual i.e driveshafts, wheel bearings and so on but the sound was coming from the back of the box. So i got googling and searching on here and it looked like it was either the center diff or the transfer case bearing but after stripping it all down they both seem fine i.e spinning freely and running smooth.

Any suggestions are welcome
Thanks

 

Could be wrong rear diff - gearbox ratio.

Mine (01 WRX) did this for months, only intermittently but it didn't feel healthy

My gearbox eventually died and I discovered that someone had fitted an 96 STI box, which I think was the cause for the grinding as it wasn't running with the rear diff properly? I fitted the correct gearbox and now it doesn't scrape at all. That's my theory anyway