Symptom Chart - Driveline

WARNING: This page is about a different car, the 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

Condition	Possible Sources	Action
Traction-Lok does not work in snow, mud or on ice	Differential	CARRY OUT the Traction-Lok Differential Operation Check in this article. REPAIR as necessary. Refer to: Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear .
Lubricant leaking from the pinion seal, axle shaft oil seals or support arm to the housing	Vent Damage in the seal contact area or dust slinger on the pinion flange dust shield	CLEAN the axle housing vent. INSTALL a new pinion flange and the pinion seal if damage is found.
The vehicle does not shift between the different modes correctly	Mode switch Wiring/relays Shift motor Transfer case Generic Electronic Module (GEM)	REFER to Four Wheel Drive (4WD) Systems .
Front axle will not engage	Switches Wiring GEM Shift motor	REFER to Four Wheel Drive (4WD) Systems .
Front axle will not disengage	Switches Wiring GEM Shift motor	REFER to Four Wheel Drive (4WD) Systems .
Differential side gears/pinion gears are scored	Insufficient lubrication	INSTALL new gears. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear or Front Drive Axle/Differential . FILL the axle to specification. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear .
Incorrect or contaminated lubricant type		INSTALL new gears. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear or Front Drive Axle/Differential . CLEAN and REFILL the axle to specification. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear .
Axle overheating	Lubricant level too low	CHECK the lubricant level. FILL the axle to specification. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear .
Incorrect or contaminated lubrication type		INSPECT the axle for damage. REPAIR as necessary. CLEAN and REFILL the axle to specification. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear .
Bearing preload adjusted too tight		CHECK the ring and pinion for damage. INSPECT the ring and pinion wear pattern. ADJUST the preload as necessary.
Excessive gear wear		INSPECT all the axle gears for wear or damaged. INSTALL new components as necessary. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear or Front Drive Axle/Differential .
Incorrect ring gear backlash		INSPECT the ring gear for scoring. INSPECT the ring and pinion wear pattern. ADJUST the ring gear backlash as necessary. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear or Front Drive Axle/Differential .
Broken gear teeth on the ring gear or pinion	Overloading the vehicle	INSTALL a new ring and pinion. REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear or Front Drive Axle/Differential .
Halfshaft broken	Overloading the vehicle	INSTALL a new axle halfshaft. REFER to Front Drive Halfshafts or Rear Drive Halfshafts .
Misaligned axle halfshaft		INSPECT the axle for damage. CHECK axle halfshaft alignment. INSTALL a new axle halfshaft. REFER to Front Drive Halfshafts or Rear Drive Halfshafts .
Gray or milky axle lubricant in low mileage vehicles	Marking compound in axle fluid	Inspect axle housing and vent for damage or leaks. Refer to Axle Fluid Analysis in this article.