Lincoln Aviator 2020-2024 Service Manual / Chassis / Driveline / Driveshaft / Diagnosis and Testing - Driveshaft

Lincoln Aviator: Driveshaft / Diagnosis and Testing - Driveshaft

Preliminary Inspection

Visually inspect the CV joints for obvious signs of mechanical damage.

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step

If the cause is not visually evident, verify the symptom and REFER to Symptom Chart: NVH.

Symptom Chart(s)

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).

Symptom Chart: NVH

Symptom Chart

Condition	Possible Sources	Actions
Driveline clunk - loud clunk when shifting from PARK or REVERSE to DRIVE	Damaged or worn driveshaft flex coupling, CV-joint and / or U-joint	INSPECT the driveshaft flex coupling, CV-joint and / or U-joint for wear or damage. INSTALL a new flex coupling or driveshaft as necessary REFER to: Driveshaft Flexible Coupling (205-01 Driveshaft, Removal and Installation). REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation).
	Driveshaft to Axle Circlip not seated, damaged or worn	INSPECT the driveshaft CV joint connection to rear axle for excessive play Re-seat CV joint to axle or INSTALL a new Driveshaft to Axle Circlip. REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation). REFER to: Front Driveshaft (205-01 Driveshaft, Removal and Installation).
	Driveshaft center bearing worn or damaged.	CHECK center bearing for isolator damage or tears. INSTALL a new center bearing as necessary. REFER to: Driveshaft Center Bearing (205-01 Driveshaft, Disassembly and Assembly).
Driveline clunk — occurs as the vehicle starts to move forward following a stop	Worn driveshaft flex coupling, CV joint and / or U-joint with excessive play	INSPECT the driveshaft flex coupling, CV-joint and / or U-joint for a worn condition. INSTALL a new flex coupling or driveshaft if necessary. REFER to: Driveshaft Flexible Coupling (205-01 Driveshaft, Removal and Installation). REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation).
	Driveshaft to Axle Circlip not seated, damaged or worn	INSPECT the driveshaft CV joint connection to rear axle for excessive play Re-seat CV joint to axle or INSTALL a new Driveshaft to Axle Circlip. REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation). REFER to: Front Driveshaft (205-01 Driveshaft, Removal and Installation).
	Driveshaft center bearing worn or damaged.	CHECK center bearing for isolator damage or tears. INSTALL a new center bearing as necessary. REFER to: Driveshaft Center Bearing (205-01 Driveshaft, Disassembly and Assembly).
Buzz – buzzing noise is the same at cruise or coast/deceleration	Incorrect driveline angles	CHECK for correct driveline angles. REPAIR as necessary. REFER to: Driveshaft Angle Measurement (205-01 Driveshaft, General Procedures).
Squeal – noise occurs at slow vehicle speeds	Driveshaft spline boot damaged and/or out of position rubbing on center bearing	CHECK for condition of rear and front driveshaft spline boot. REPLACE rear and front driveshaft spline boot as necessary. REFER to: Rear Driveshaft Slip Yoke Boot (205-01 Driveshaft, Removal and Installation). REFER to: Front Driveshaft Slip Yoke Boot (205-01 Driveshaft, Removal and Installation).
Rumble or Boom – noise occurs at coast/ deceleration, usually driveshaft speed-related and noticeable over a wide range of speeds	Driveshaft out of balance	CHECK the driveshaft for damage, missing weights or undercoating. INSTALL a new driveshaft as necessary. REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation).
	Center bearing worn or damaged.	CHECK center bearing for isolator damage and excessive bearing wear/clearance. INSTALL a new center bearing as necessary. REFER to: Driveshaft Center Bearing (205-01 Driveshaft, Disassembly and Assembly).
	Pilot or alignment bushing worn or damaged.	CHECK pilot or alignment bushing for wear or damage. INSTALL a new pilot or alignment bushing as necessary. REFER to: Driveshaft Alignment Bushing (205-01 Driveshaft, Disassembly and Assembly).
Grunting — normally associated with a shudder experienced during acceleration from a complete stop	Driveshaft CV-joint and / or U-joint binding	INSPECT the driveshaft CV-joint and / or U-joint and coupling shaft for wear or damage. INSTALL a new rear driveshaft and driveshaft U-joint as necessary. REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation). REFER to: Driveshaft Universal Joint (205-01 Driveshaft, Disassembly and Assembly).
	Driveshaft splines binding	CHECK splines for plunge. LUBRICATE splines with grease as necessary. REFER to: Rear Driveshaft Slip Yoke Boot (205-01 Driveshaft, Removal and Installation). REFER to: Front Driveshaft Slip Yoke Boot (205-01 Driveshaft, Removal and Installation).
Driveline shudder – occurs during acceleration from a slow speed or stop	Driveline angles out of specification	CHECK for correct driveline angles. REFER to: Driveshaft Angle Measurement (205-01 Driveshaft, General Procedures).
	Binding or damaged driveshaft CV-joint and/or U-joint	INSPECT the driveshaft CV-joint and / or U-joint and coupling shaft for wear or damage. INSTALL a new rear driveshaft and driveshaft U-joint as necessary. REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation). REFER to: Driveshaft Universal Joint (205-01 Driveshaft, Disassembly and Assembly).
	Driveshaft splines binding	CHECK splines for plunge. LUBRICATE splines with grease as necessary. REFER to: Rear Driveshaft Slip Yoke Boot (205-01 Driveshaft, Removal and Installation). REFER to: Front Driveshaft Slip Yoke Boot (205-01 Driveshaft, Removal and Installation).
Driveline vibration - occurs at cruising speeds	Loose driveshaft center bearing support, flex coupler, or flange fasteners	CHECK center bearing bracket, flex coupler, and flange fastener torque. REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation).
	Worn or damaged driveshaft center bearing support	CHECK the insulator for damage or wear. ROTATE the driveshaft and CHECK for rough operation. INSTALL a new center bearing or driveshaft as necessary. REFER to: Driveshaft Center Bearing (205-01 Driveshaft, Disassembly and Assembly). REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation).
	Pilot or alignment bushing worn or damaged.	CHECK pilot or alignment bushing for wear or damage. INSTALL a new pilot or alignment bushing as necessary. REFER to: Driveshaft Alignment Bushing (205-01 Driveshaft, Disassembly and Assembly).
	Excessive axle pinion stem runout	MEASURE pinion stem runout at circlip groove with a dial indicator while rotating the axle pinion. REPAIR as necessary. REFER to: Specifications (205-01 Driveshaft, Specifications).
	Excessive transmission (4x2) or transfer case (4x4) flange flex coupling pilot stem runout	Measure output shaft pilot stem runout using a dial indicator while rotating the output flange in neutral. REFER to: Specifications (205-01 Driveshaft, Specifications).
	Driveshaft is out of balance	CHECK the driveshaft for damage, missing balance weights or undercoating. CHECK the driveshaft balance. Reindex rear driveshaft to axle pinion 180° (yellow dot opposite). REFER to: Driveshaft Runout and Balancing (205-01 Driveshaft, General Procedures). CARRY OUT a driveline vibration test.
	Binding or damaged driveshaft flex coupling, CV-joint and / or U-joint	INSPECT the driveshaft flex coupling, CV-joint of rear driveshaft and U-joint of front driveshaft for wear or damage. INSTALL a new flex coupling or rear driveshaft if necessary. INSTALL front driveshaft U- joint as necessary. REFER to: Driveshaft Flexible Coupling (205-01 Driveshaft, Removal and Installation). REFER to: Rear Driveshaft (205-01 Driveshaft, Removal and Installation). REFER to: Driveshaft Universal Joint (205-01 Driveshaft, Disassembly and Assembly).
	Excessive driveshaft runout	CARRY OUT a runout check. REFER to: Driveshaft Runout and Balancing (205-01 Driveshaft, General Procedures).
	Driveline angles out of specification	CHECK for correct driveline angles. REPAIR as necessary. REFER to: Driveshaft Angle Measurement (205-01 Driveshaft, General Procedures).

Specifications

Lubricants, Fluids, Sealers and Adhesives NOTICE: Do not over-lubricate the driveshaft components. Using excessive grease may damage the driveshaft components...

General Procedures - Driveshaft Angle Measurement

Check NOTE: Prior to checking driveline angularity, inspect the U-joints for correct operation. NOTE: An incorrect driveline angle can cause a vibration or shudder...

Other information:

Lincoln Aviator 2020-2024 Owners Manual: Using Lower Anchors and Tethers for CHildren (LATCH)

WARNING: Do not attach two child safety restraints to the same anchor. In a crash, one anchor may not be strong enough to hold two child safety restraint attachments and may break, causing serious injury or death. WARNING: Depending on where you secure a child restraint, and depending on the child restraint design, you may block access to certain seatbelt buckle assemblies and LATCH lower anchors, rendering those features potentially unusable...

Lincoln Aviator 2020-2024 Owners Manual: Vehicle Identification Number

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Emergency Locking

Each door has a backup power system which allows the door to function if your vehicle has no power. The system has a limited number of operations before the power is depleted and turns off. When the system turns off, the door remains open and unlatched and does not close.

If your vehicle has no power and the backup power system is turned off, you can close and secure your vehicle by manually resetting each door latch using a key in the position shown.