[Walt Fricke]

How about "Check play between selector fork and operating sleeve of 1st through 5th gears. Distance "a" = max. 0.5 mm." That is from a loose page copied from a Porsche publication with 911 Carrera Manual Transmission / Gears and Shafts 35 heading I have stored in my Assembly Group 3 volume of the manual I have (pre-3.2, but the 915 is the same).

So this accounts for wear on the operating sleeve as well as the (much softer?) fork.