| In a manual transmission, part of the synchronizer assembly. A brass ring that brings the driven gear to shaft speed before engagement. | |
| Electronic control unit | |
| And enclosure for the differential and drive axles. | |
| A magnetic, hall effect, optical or magneto resistive sensor usually mounted internally in the engine, externally to the engine are in the distributor to inform the ECM or PCM of the crankshaft position location of No. 1 piston, and crankshaft speed for ignition timing and other calculationneeded by the system where RPM is in input. |