Visually check for obvious signs of mechanical or electrical 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 apparent, verify the symptom and refer to the Symptom Chart.
Symptom Chart - Front Differential
Symptom Chart - Front Differential
Condition
Possible Sources
Action
Axle Overheating
Low axle lubricant level
CHECK the lubricant level. FILL the axle to specification. REFER TO: Specifications (205-03 Front Axle/Differential, Specifications).
Incorrect or contaminated lubricant type
CHECK the axle for damage. REPAIR as necessary. DRAIN and FILL the axle to specification as necessary. REFER TO: Specifications (205-03 Front Axle/Differential, Specifications).
Bearing preload adjusted too tight.
If the vehicle has low mileage, CHECK the ring gear and pinion for damage. INSTALL a new front axle if necessary. REFER TO: Axle Assembly (205-03 Front Axle/Differential, Removal and Installation).
Excessive gear wear
INSPECT all axle gears for wear or damage. INSTALL a new front axle assembly if necessary. Refer to: Axle Assembly (205-03 Front Drive Axle/Differential, Removal and Installation).
Broken gear teeth on the ring gear or pinion
Insufficient lubrication
INSTALL the front axle assembly. Refer to: Axle Assembly (205-03 Front Drive Axle/Differential, Removal and Installation).
Differential side gears / differential pinion gears clogged
Incorrect or contaminated lubricant type
Drain and FILL the axle to specification. Refer to: Differential Draining and Filling (205-03 Front Drive Axle/Differential, General Procedures). Road test the vehicle. If a visible symptom (noise from the front axle) is present, INSTALL a new front axle assembly if necessary. Refer to: Axle Assembly (205-03 Front Drive Axle/Differential, Removal and Installation).
Fluid leak from the pinion seal or axle shaft seal
vent
CLEAN the axle housing vent.
Damage in the sealing area of the pinion flange seal or dust shield
INSTALL a new pinion nut and pinion seal if damage is found. Refer to: Pinion Seal (205-03 Front Drive Axle/Differential, Removal and Installation).
Damage in the seal contact area
INSTALL a new axle shaft seal as necessary. Inspect the axle shaft seal contact area. Install a new axle shaft as required. Refer to: Axle Shaft Seal (205-03 Front Drive Axle/Differential, Removal and Installation).
Lubricant squeezed out from the pinion splines
Missing / worn / damaged front drive shaft to pinion retaining ring
Missing / damaged front axle pinion shaft O-ring
REMOVE the front drive shaft. INSTALL a new retaining ring and O-ring. INSTALL a new front drive shaft as required. Refer to: Front Propeller Shaft (205-01 Propeller Shaft, Removal and Installation).
Symptom Chart - NVH
Refer to: Noise, Vibration and Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing).
Symptom Chart - NVH
Condition
Possible Sources
Action
NVH concern isolated to the front axle using the appropriate diagnostic tools. The symptom may be constant or occur only under certain driving conditions.
Low axle lubricant level or contamination
CHECK the lubricant level. FILL the axle to specification. Refer to: Differential Fluid Level Check (205-03 Front Drive Axle/Differential, General Procedures). OR CHECK the front axle fluid as necessary. Drain and FILL the axle to specification. Refer to: Differential Draining and Filling (205-03 Front Drive Axle/Differential, General Procedures).
Internal FDU (front drive unit) damage
Remove the side cover and inspect the components for wear or damage. INSTALL a new FDU (front drive unit) as necessary. Refer to: Axle Assembly (205-03 Front Drive Axle/Differential, Removal and Installation).
Transmission clunk - loud clunk when shifting from REVERSE to DRIVE.
Loose or missing fasteners
CHECK all propeller shaft fasteners for proper torque.
Transmission shudder - occurs when the vehicle begins to move forward from a stop.
Loose front axle mounting
CHECK the front axle for loose bolts. TIGHTEN to specified torque. Refer to: Axle Assembly (205-03 Front Drive Axle/Differential, Removal and Installation).
Clunk in the driveline - occurs during acceleration or from cruise to coast / braking.
Rear propeller shaft U-joint
Missing or damaged retaining ring on the front axle pinion.
CHECK the rear propeller shaft U-joints for wear or damage. INSTALL a new rear propeller shaft if necessary. Refer to: Rear Propeller Shaft (205-01 Propeller Shaft, Removal and Installation).
Install a new retaining ring.
Grunt - usually associated with shudder occurring on acceleration after a complete stop.
Rear Driveshaft
CHECK the rear drive shaft. INSTALL a new rear drive shaft. Refer to: Rear Propeller Shaft (205-01 Propeller Shaft, Removal and Installation).
Scraping noise - continuous low-frequency noise starting at low speeds.
Left axle shaft seal deflector bent / damaged (intermediate shaft)
CHECK the components for wear / damage. INSTALL a new left axle shaft seal if necessary. Refer to: Axle Shaft Seal (205-03 Front Drive Axle/Differential, Removal and Installation).
Driveline shudder - occurs during low speed acceleration or stopping.
Rear Driveshaft
CHECK the rear drive shaft. INSTALL a new rear drive shaft. Refer to: Rear Propeller Shaft (205-01 Propeller Shaft, Removal and Installation).
Axle Fluid Analysis
A milky-colored fluid may be caused by fluid contamination. Drain and refill the fluid and repeat the check for normal operation. Refer to: Differential Draining and Filling (205-03 Front Drive Axle/Differential, General Procedures).
Leak Analysis
Clean the leak area sufficiently to determine the exact source.
Axle Vent
A clogged vent will cause excessive wear of the seal lip due to internal pressure buildup. If leakage occurs, check the vent. If the vent cannot be cleaned, install a new vent.
Pinion Seal
Pinion seal leaks are caused by the following conditions:
Damaged seal
Worn seal surface on the pinion nut
The available service kit includes the seal, nut and deflector.
Differential Seals
NOTICE: When installing the axle shafts, do not allow the splines to contact the seals during installation, otherwise seal damage may occur.
Front axle fluid level must be up to the axle shaft. Top up the fluid level after replacing any differential seal. Seals are single-use and must be replaced whenever the right axle shaft or intermediate shaft is removed.
The right-hand axle shaft seal is a typical unitized seal used in many applications. The left differential seal is an O-ring between the shaft and the oil pan.
The intermediate shaft also contains a differential seal to prevent lubricant from reaching the intermediate shaft. This seal is serviced with the intermediate shaft.
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