A howling differential is one of the worst sounds any car guy (or girl) can hear. And once you’ve heard a clunk, howl, whine, or vibration, you’ll want to diagnose it.
It’s possible that the sounds you’re hearing are not differential-related. They could be caused by other driveline or axle components.
This quick guide will help you match those alarming sounds to the vehicle component that’s making them.
Typical Symptoms & Possible Causes
Noises, vibrations and other irregular driving characteristics are often caused by a problem with your differential or driveline.
| Symptom | Howling when decelerating (gears were previously quiet) |
|---|---|
| Cause | Loose pinion bearing preload |
| Symptom | Howling with whirring or a rumble when accelerating (gears previously quiet) |
|---|---|
| Cause | Worn out rear pinion bearing or worn out gear set |
| Symptom | Howling when accelerating over a shorter speed range (gears previously quiet) |
|---|---|
| Cause | Worn gear set caused by bad lubrication or overloading |
| Symptom | Howling after installing a gear set |
|---|---|
| Cause | Faulty installation or faulty gears |
| Symptom | Low rumble at any speed over 30 km/h |
|---|---|
| Cause | Worn carrier bearings |
| Symptom | Whirring sounds when accelerating or decelerating at around 15 km/h |
|---|---|
| Cause | Worn pinion bearings |
| Symptom | Hard banging or clunking sounds when turning, backing up, or rapidly decelerating, with the sounds getting worse in warmer weather |
|---|---|
| Cause | Positraction chatter caused by improper lubrication, worn clutches, worn spider gears, or improper assembly |
| Symptom | Hard banging, crunching, or popping sounds when turning |
|---|---|
| Cause | Very worn or even broken spider gears |
| Symptom | Banging or clicking every couple of feet when accelerating or decelerating |
|---|---|
| Cause | Broken pinion gear teeth |
| Symptom | Banging or clicking every couple of feet when accelerating or decelerating, but never both |
|---|---|
| Cause | Heavy chip on pinion gear tooth |
| Symptom | Banging or clicking every eight to ten feet when accelerating or decelerating |
|---|---|
| Cause | Broken ring gear teeth |
| Symptom | Banging or clicking every eight to ten feet when accelerating or decelerating, but never both |
|---|---|
| Cause | Heavy chip on ring gear tooth |
| Symptom | Clicking sounds when decelerating from 30 km/h to a complete stop |
|---|---|
| Cause | Worn carrier case-side gear bores |
| Symptom | Rumbling or clicks that sound worse when making a hard turn |
|---|---|
| Cause | Bad wheel bearings |
| Symptom | Squeaking or grinding driveline |
|---|---|
| Cause | Worn or damaged U-joints |
| Symptom | Clunks when pressing down on the throttle pedal during takeoff |
|---|---|
| Cause | Worn U-joints, spider gears, axle splines, excessive gear backlash, or loose or worn yoke splines |
| Symptom | Clunking noises heard upon takeoff from a complete stop |
|---|---|
| Cause | Worn slip yoke splines |
| Symptom | Steady vibration which increases as you gain more speed |
|---|---|
| Cause | Worn U-joint or misbalanced driveshaft |
| Symptom | Cyclic vibrations with high intensity at a specific speed range, and during deceleration |
|---|---|
| Cause | Lower-than-needed pinion angle (not parallel with front yoke on driveshaft) |
