Transmission noise in reverse Options

[patssle]

Car is making pretty loud noise when reversing and then throwing in the clutch. Works absolutely fine in all forward gears and no problems with 1st gear. Shifting does not grind the gears at all. It has worked fine for several years since I had the transmission rebuilt by a reputable Porsche mechanic. It seemed to start after I accidently grinded reverse.

I've taken the rear off and have looked at the bearings and reverse gear - everything looks ok. Is there anything I can do to verify the bearings are okay?

But looking at the drawing diagram - doesn't the reverse idler gear always turn regardless of what gear you're in? Could it be the shifting gear for 1st/reverse - but then wouldn't it make the noise in 1st too? Sees as soon as I yank the shifter out of reverse the noise stops.