[Mark Salvetti]

Here area a few threads that may help.

http://forums.pelicanparts.com/porsche-911-technical-forum/274915-915-r-p-whine-how-do-you-get-rid-fix-2.html (Second page especially)
http://forums.pelicanparts.com/porsche-911-technical-forum/1034309-opinions-915-ring-pinion-contact-pattern.html?highlight=wear+pattern
http://forums.pelicanparts.com/porsche-911-technical-forum/1063543-checking-mesh-pattern-930-final-does-looks-ok.html?highlight=wear+pattern
http://forums.pelicanparts.com/porsche-911-technical-forum/1012138-comments-ring-pinion-mesh-pattern.html

Mark