Lock washers or spring washers come in many different forms, including several types used in our classic Volkswagens. One locking ring you won't find on the hardware store shelf is the wave spring washer.
Thanks to the action of the circular spring, a continuous tension is maintained between the parts on which the corrugated spring washer is mounted. These may be bolt and nut assemblies, but you may also come across them in shaft assemblies.
In common parlance, they are dimensioned in "M" (M4, M5, etc.), which is not quite accurate. The "M" stands for metric or thread pitch. The official measurement should be the inside diameter of the corrugated spring washer, e.g. 8.4 mm (which we mistakenly call M8 ).
Volkswagen uses two types of 8.4 mm (M8 ) corrugated spring washers. The difference lies in the outside diameter. The standard outer diameter is 15 mm. Primarily for more heavily loaded parts, the pressure area has been increased by 2 mm, giving the ring an outer diameter of 17 mm.
Be sure to use the correct corrugated spring washer as specified by Volkswagen, as this is the only way to ensure perfect locking.
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