Sentra Sedan L4-1597cc 1.6L SOHC (E16S) (1986)
Crankshaft - Drive Plate/Flywheel Alignment Dowel Pin
Most late model engines have an alignment dowel installed in the rear of the crankshaft.
This dowel is used to properly align (locate) the drive plate or flywheel with the crankshaft.
If you replace an engine that uses this dowel, make sure it is installed during re-assembly.
On engines that use this dowel:
During re-assembly, the drive plate or flywheel locating hole must be aligned with this dowel for proper operation of the engine control
If not aligned (clocked) correctly, rough running and MIL "ON" will occur.
Torque Converter Pilot (A/T) Pilot Bushing (M/T)