For 1991-95 models, Chrysler made available an All Wheel Drive (AWD) version of the Caravan/Voyager. The AWD equipped vehicles use the same basic drivetrain layout as the front wheel drive versions, with the exception of the rear driveline module. To transfer the power from the engine and transaxle, to the rear driveline module, these vehicles use an Power Transfer Unit (PTU). The PTU is connected to the transaxle where the right halfshaft extension housing would be.
The PTU is a separate unit from the transaxle. It uses a standard hypoid type ring and pinion. The PTU is sealed from the transaxle and has its own oil sump. The unit uses SAE 85W-90 gear lube and holds 1.22 qts.
The PTU is not a repairable unit and can only be replaced. If you suspect the PTU has failed, take the vehicle to an authorized service center.