RB20 RB25 RB26 Crankshaft Woodruff Key
OEM Nissan Woodruff key
The RB series engines require two of these. The first one is installed into the snout of the crankshaft, and it locates the timing gear indexed properly with the position of the crankshaft,
The second one, is used to locate the crankshaft pulley - indexing it at the correct angle for proper timing of the engine using the timing marks on the pulley.