Power Transfer Unit (PTU)
WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The Power Transfer Unit (PTU) is a gearbox that attaches to the transaxle. On automatic transaxle vehicles, the RH intermediate shaft passes through the PTU and engages the differential side gear as in normal Front Wheel Drive (FWD) applications. The PTU directs power to the rear driveshaft through a helical gear spline coupled to the transaxle differential case, a helical gear drop (idler gear), and hypoid/helical ring gear assembly and pinion set.
NOTE:
Repair of the PTU is limited to seals, gaskets and output flange. If any of the geared components, bearings, case cover or internal shafts fail, a new PTU must be installed.
The PTU is sealed from the transaxle and has its own oil sump. The PTU on an automatic transaxle vehicle uses 0.35L (12 oz) of Motorcraft SAE 75W-140 synthetic lubricant. The PTU on a manual transaxle vehicle uses 0.35L (12 oz) of Motorcraft 80W-90 synthetic lubricant.