912 uls gearbox "rubbing noise"
I have a 912 s engine (580 hrs) with a 3 blade 70" warp drive propeller. I noticed recently a "rubbing" noise coming from the gear box while turning it to gurgle the engine to check the oil level. Does anyone else hear a similar noise while turning the prop ? I have checked the magnetic plug which was clean. I check the friction torque which was good. I also pulled the fuel pump to see if the noise was coming from it, which it wasn't. The hub seems tight (no play).
Any ideas ?
Thanks