Symptom Table - Power Transfer Unit (PTU): Notes

WARNING: This page is about a different car, the 2010 Mercury Milan and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

POWER TRANSFER UNIT (PTU) SYMPTOM TABLE

Condition	Possible Sources	Action
The Power Transfer Unit (PTU) makes noise	Tire inflation pressure Tire and wheel size	MAKE SURE all tires and wheels are the same size and brand and the inflation pressures are correct.
-	Fluid level	FILL with the correct type and amount of lubricant. REFER to POWER TRANSFER UNIT (PTU) DRAINING AND FILLING .
-	Internal components	OPERATE the vehicle in all gears. If there is noise in the transaxle in NEUTRAL, or in some gears and not in others, REMOVE and REPAIR the transaxle. Refer to IN-VEHICLE REPAIR , AUTOMATIC TRANSAXLE/TRANSMISSION - AISIN AW21 and/or AUTOMATIC TRANSAXLE/TRANSMISSION - ELECTRONICALLY CONTROLLED CONTINUOUSLY VARIABLE TRANSMISSION (ECVT) for the procedure. If there is noise in all gears, INSTALL a new PTU. REFER to INSTALLATION .
Leaking fluid from the PTU vent	PTU over filled	REFER to ANALYSIS OF LEAKAGE .
Leaking automatic transmission fluid	PTU intermediate shaft seal PTU compression seal	REFER to ANALYSIS OF LEAKAGE .
Leaking gear lubricant from the seals	The PTU vent is plugged (located on top of the PTU)	INSTALL a new PTU. REFER to INSTALLATION .
-	Damaged seals	REFER to ANALYSIS OF LEAKAGE .
Vehicle has no or inadequate torque at rear wheels	Rear axle	REFER to REAR DRIVE AXLE AND DIFFERENTIAL .
-	PTU mechanical failure	REFER to POWER TRANSFER UNIT (PTU) .
Vehicle binds in a turn or resists turning/pulsates or shudders in a straight line	Wheels/tires	REFER to WHEELS AND TIRES .
-	Brake system	REFER to BRAKE SYSTEM .
-	Wheel bearings	REFER to SUSPENSION SYSTEM - GENERAL INFORMATION .
-	Halfshafts	REFER to HALFSHAFTS .
-	Wheel speed sensor(s)	REFER to VEHICLE DYNAMIC SYSTEMS .
-	ABS module	REFER to ABS MODULE CONFIGURATION .