Power Transfer Unit
The Power Transfer Unit (PTU) input shaft is driven directly from the transmission differential. When the electrically operated dog clutch mechanism is in the disengaged position, the crown wheel shaft and the crown wheel disconnects from the input shaft. No drive is transferred to the driveshaft or the Rear Drive Unit (RDU).
When the dog clutch is engaged, drive is transferred from the transmission differential, through the dog clutch to the crown wheel shaft. The crown wheel rotates and transmits the drive through 90° to the pinion gear and the drive flange to rotate the driveshaft.
For additional information, Refer to: POWER TRANSFER UNIT .