Symptom Chart — Driveline
Symptom Chart — Driveline
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 section. REPAIR as necessary. REFER to Section 205-02B.
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.
Differential side gears/pinion gears are scored
Insufficient lubrication
INSTALL new gears. REFER to Section 205-02A or Section 205-02B. FILL the axle to specification.
Incorrect or contaminated lubricant type
INSTALL new gears. REFER to Section 205-02A or Section 205-02B. CLEAN and REFILL the axle to specification.
Axle overheating
Lubricant level too low
CHECK the lubricant level. FILL the axle to specification.
Incorrect or contaminated lubrication type
INSPECT the axle for damage. REPAIR as necessary. CLEAN and REFILL the axle to specification.
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 damage. INSTALL new components as necessary.
Incorrect ring gear backlash
INSPECT the ring gear for scoring. INSPECT the ring and pinion wear pattern. ADJUST the ring gear backlash as necessary.
Broken gear teeth on the ring gear or pinion
Overloading the vehicle
INSTALL a new ring and pinion. REFER to Section 205-02A or Section 205-02B.
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 section.
Symptom Chart — NVH
Symptom Chart — NVH
Condition
Possible Sources
Action
NOTE: NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, refer to Section 100-04. Since it is possible any one of multiple systems may be the cause of a symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, refer back to Section 100-04 for the next likely system and continue diagnosis.
Axle howling or whine
Axle lubricant low
CHECK the lubricant level. FILL the axle to specification. REFER to Section 205-02A or Section 205-02B.
Tuned dampers missing or incorrectly installed
REFER to the TSB and follow the procedure outlined.
Axle housing damage
INSPECT the axle housing for damage. REPAIR or INSTALL a new axle as necessary. REFER to Section 205-02A or Section 205-02B.
Damaged or worn wheel hub bearings
CHECK for abnormal rear wheel bearing play or roughness. INSTALL a new wheel bearing as necessary. REFER to Section 205-02A or Section 205-02B.
Damaged or worn differential ring and pinion
INSPECT and INSTALL a new differential ring and pinion as necessary. REFER to Section 205-02A or Section 205-02B.
Damaged or worn differential side or pinion bearings
INSPECT and INSTALL new differential side or pinion bearings as necessary. REFER to Section 205-02A or Section 205-02B.
Driveline clunk — loud clunk when shifting from REVERSE to DRIVE
Incorrect axle lubricant level
CHECK the lubricant level. FILL the axle to specification. REFER to Section 205-02A or Section 205-02B.
Excessive backlash in the axle
CHECK the ring gear backlash. REPAIR as necessary. REFER to Section 205-02A or Section 205-02B.
Damaged or worn pinion bearings
REPAIR or INSTALL new pinion bearings as necessary. REFER to Section 205-02A or Section 205-02B.
Damaged or worn U-joints
INSPECT the U-joints for wear or damage. INSTALL new U-joints or driveshaft as necessary. REFER to Section 205-01.
Driveline clunk — occurs as the vehicle starts to move forward following a stop
Worn driveshaft CV joint or U-joints
INSPECT the CV joint and U-joints for wear. INSTALL a new driveshaft or U-joints as necessary. REFER to Section 205-01.
Loose axle mount
CHECK the axle for loose bolts. TIGHTEN to specification. REFER to Section 205-02A or Section 205-02B.
High pitched chattering — noise from the axle when the vehicle is turning
Incorrect or contaminated lubricant
CHECK the vehicle by driving in tight circles (5 clockwise, 5 counterclockwise). FLUSH and REFILL with the specified rear axle lubricant and friction modifier as necessary.
Damaged or worn differential (differential side gears and pinion gears)
REPAIR or INSTALL new differential side gears or pinion gears as necessary. REFER to Section 205-02A or Section 205-02B.
Rumble or boom — noise occurs at coast/deceleration, usually driveshaft speed-related and noticeable over a wide range of speeds
Excessive driveshaft runout and/or driveshaft is out-of-balance
CHECK the driveshaft runout and balance. REFER to Driveshaft Runout and Balancing in this section.
Binding or seized U-joints
ROTATE the driveshaft and CHECK for binding or seized U-joints. INSTALL new U-joints or driveshaft as necessary. REFER to Section 205-01.
Grunting — normally associated with a shudder experienced during acceleration from a complete stop
Binding driveshaft CV joint
INSPECT the driveshaft CV joint for binding. INSTALL a new driveshaft as necessary. REFER to Section 205-01.
Loose axle mount bolts or suspension fasteners
INSPECT the rear suspension and axle. TIGHTEN the fasteners to specification. REFER to Section 205-02A or Section 205-02B.
Howl — can occur at various speeds and driving conditions. Affected by acceleration and deceleration
Incorrect ring and pinion contact, incorrect bearing preload or gear damage
INSPECT and REPAIR as necessary. REFER to Section 205-02A or Section 205-02B.
Chuckle — heard at coast/deceleration. Also described as a knock
Incorrect ring and pinion contact or damaged teeth on the coast side of the ring and pinion
INSPECT and REPAIR as necessary. REFER to Section 205-02A or Section 205-02B.
Knock — noise occurs at various speeds. Not affected by acceleration or deceleration
Gear tooth damage to the drive side of the ring and pinion
INSTALL a new ring and pinion. REFER to Section 205-02A or Section 205-02B.
Scraping noise — a continuous low pitched noise starting at low speeds
Worn or damaged pinion bearings
INSPECT and REPAIR or INSTALL new pinion bearings. REFER to Section 205-02A or Section 205-02B.
Driveline shudder — occurs during acceleration from a slow speed or stop
Incorrect transmission crossmember orientation
CHECK for correct orientation. REINSTALL if necessary. REFER to Section 502-00.
Center bearing spacer missing or incorrectly installed
CHECK for correct installation of center bearing spacer. REFER to Section 205-01.
Drive axle assembly mispositioned
CHECK the axle mounts and the rear suspension for damage or wear. REPAIR as necessary. REFER to Section 205-02A or Section 205-02B.
Loose axle bolts
CHECK the axle for loose bolts. TIGHTEN the bolts to specification. REFER to Section 205-02A or Section 205-02B.
Driveline angles out of specification
CHECK for correct driveline angles. REFER to Driveline Angle Measurement in this section. For vehicles equipped with a 2 piece driveshaft, ADJUST the driveline angle as neccesary. REFER to Driveline Angle Adjustment In this section.
U-joints binding or seized
ROTATE the driveshaft and CHECK for binding or seized U-joints. INSTALL new U-joints or driveshaft as necessary. REFER to Section 205-01.
Binding or damaged driveshaft CV joint
INSPECT the driveshaft CV joint for binding or damage. INSTALL a new driveshaft as necessary. REPAIR as necessary. REFER to Section 205-01.
Driveline vibration — occurs at cruising speeds
Missing weights or damage to driveshaft
INSPECT the driveshaft. INSTALL a new driveshaft as necessary. REFER to Section 205-01.
Worn U-joints
CHECK for wear or incorrect seating. INSTALL new U-joints or driveshaft as necessary. REFER to Section 205-01.
Misalignment of yellow dot on driveshaft-to-yellow dot on pinion flange plus or minus 1 bolt hole
REINSTALL driveshaft with yellow dots aligned plus or minus 1 bolt hole. REFER to Section 205-01.
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 driveshaft as necessary. REFER to Section 205-01.
Loose axle pinion flange bolts
INSPECT the axle pinion flange. TIGHTEN the pinion flange bolts to specification. REFER to Section 205-01.
Excessive axle pinion flange runout
CHECK the pinion flange runout. REPAIR as necessary. REFER to Pinion Flange Runout Check in this section.
Excessive transmission flange runout
CHECK the transmission flange runout. REPAIR as necessary. REFER to Specification in this section.
Binding or damaged driveshaft CV joint
INSPECT the driveshaft CV joint for binding or damage. INSTALL a new driveshaft as necessary. REFER to Section 205-01.
Excessive driveshaft runout and/or driveshaft out-of-balance
CHECK the driveshaft runout and balance. REFER to Driveshaft Runout and Balancing in this section.
Driveline angles out of specification
CHECK for correct driveline angles. REPAIR as necessary. REFER to Driveline Angle Measurement in this section.
Transmission mount not centered
NEUTRALIZE the transmission mount. REFER to the Transmission Crossmember procedure in Section 502-00.
Axle Fluid Analysis
The appearance of milky or gray axle fluid in early mileage axles is a result of white marking compound used at the assembly plant to verify gear mesh contact pattern. The marking compound within the fluid will darken some over time. The milky fluid appearance will diminish and cause no harm and does not require a fluid change.
Analysis of Leakage
Clean up the leaking area enough to identify the exact source.
A plugged axle housing vent can cause excessive pinion seal lip wear due to internal pressure buildup.
Verify the lubricant level is at specification.
Axle Vent
A plugged vent will cause excessive seal lip wear due to internal pressure buildup. If a leak occurs, check the vent. If the vent cannot be cleared, install a new vent.
Drive Pinion Seal
Leaks at the drive pinion seal originate from the following causes:
Damaged seal
Worn seal journal surface
Any damage to the seal bore (dings, dents, gouges or other imperfections) distorts the seal casing and allows leakage past the outer edge of the drive pinion seal.
The drive pinion seal can be torn, cut or gouged if it is not installed correctly. The spring that holds the drive pinion seal against the pinion flange may be knocked out and allow fluid to pass the lip.
Metal chips trapped at the sealing lip can cause oil leaks. These can cause a wear groove on the drive pinion flange and result in pinion seal wear.
When a seal leak occurs, install a new drive pinion seal and check the vent to make sure it is clean and free of foreign material.
A new drive pinion flange must be installed if any of these conditions exist.
Drive Pinion Nut
NOTICE: Install the drive pinion nut to the correct torque specifications or damage to the differential components may occur.
On some high-mileage vehicles, oil may leak through the threads of the drive pinion nut. This condition can be corrected by installing a new nut and applying threadlock on the threads and nut face.
Differential Seals
NOTICE: When installing shafts, do not allow splines to contact seals during installation or damage to the seals may occur.
Axle shaft housing seals are susceptible to the same types of damage as drive pinion seals if incorrectly installed. The seal bore must be clean and the lip handled carefully to avoid cutting or tearing it. The seal journal surface must be free of nicks, gouges and rough surface texture.
For information on differential seals, refer to Section 205-02A or Section 205-02B.
Component Tests
Traction-Lok Differential Operation Check
A Traction-Lok differential can be checked for correct operation without removing it from the rear axle housing.
Raise and remove only one rear wheel. Install the Differential Gauge on the wheel bolts.
Use a torque wrench with the capacity of at least 271 Nm (200 lb-ft) to rotate the axle shaft. Make sure that the transmission is in NEUTRAL, and that one rear wheel is on the floor while the other rear wheel is raised off the floor. The breakaway torque required to start rotation must be at least 27 Nm (20 lb-ft). The initial breakaway torque may be higher than the continuous turning torque.
The axle shaft must turn with even pressure throughout the check without slipping or binding. If the torque reading is less than specified, check the differential case for incorrect assembly.
Traction-Lok Differential Check Road Test
Place one wheel on a dry surface and the other wheel on ice, mud or snow.
Gradually open the throttle to obtain maximum traction prior to break away. The ability to move the vehicle demonstrates correct performance of a Traction-Lok rear axle assembly.
When starting with one wheel on an excessively slippery surface, a slight application of the parking brake may be necessary to help energize the Traction-Lok feature of the differential. Release the brake when traction is established. Use light throttle on starting to provide maximum traction.
If, with unequal traction, both wheels slip, the limited slip rear axle has done all it can possibly do.
In extreme cases of differences in traction, the wheel with the least traction may spin after the Traction-Lok has transferred as much torque as possible to the non-slipping wheel.
Tooth Contact Pattern Check — Gearset
To check the gear tooth contact, paint the gear teeth with the special marking compound. A mixture that is too wet will run and smear; a mixture that is too dry cannot be pressed out from between the teeth.
Use a box wrench on the ring gear bolts as a lever to rotate the ring gear several complete revolutions in both directions or until a clear tooth contact pattern is obtained.
Certain types of gear tooth contact patterns on the ring gear indicate incorrect adjustment. Incorrect adjustment can be corrected by readjusting the ring gear or the pinion.
Contact Pattern Location
In general, desirable ring gear tooth patterns must have the following characteristics:
Drive pattern on the drive side ring gear well centered on the tooth.
Coast pattern on the coast side ring gear well centered on the tooth.
Clearance between the pattern and the top of the tooth.
No hard lines where the pressure is high.
Acceptable Ring Gear Tooth Patterns For All Axles
Correct Backlash With a Thinner Pinion Position Shim Required
Correct Backlash With a Thicker Pinion Position Shim
Correct the Pinion Position Shim That Requires a Decrease in Backlash
Correct Pinion Position Shim That Requires an Increase in Backlash