Common Differential Problems
Differential leaks are fairly common in older and higher mileage vehicles. A leaking differential may not present any functional problems today, but given enough time, it can cause your vehicle to stop transferring energy from the engine to the wheels as efficiently as possible. This can result in lower gas mileage, higher differential running temperatures, and eventual system failure.
Your differential may whine if you have bad or low oil. Whining may be more noisy while you’re turning, due to the added friction caused by the dry differential gears. You may have a leaky differential, or you may simply need to replace the oil.
Your differential relies on carrier bearings to run smoothly. With bad bearings, your vehicle may begin to rumble or it may create a whirring noise, especially at faster speeds. The carrier bearings of your differential may need to be replaced to ensure that it operates without a hiccup.
Howling noises are an indication that the pinion-bearing preload is loose in your differential assembly. The howl will likely occur as you shift gears, since pressure travels through the pinion-bearing. Howling will occur as you are decelerating, and may often be confused with a tire howl.
Worn Out U-Joints
Differentials featuring U-joints may end up shaking or vibrating if the U-joints wear out. When U-Joints no longer fit together tightly, the drive shaft and axle may shutter as the joints spin. Vibrations and shuttering will be more violent at higher speeds. Be sure to have your U-joints replaced before they fail entirely, since shuttering can quickly wear out the joints.
Broken Gear Teeth
Your differential houses gears that transfer power to the axles of your vehicle. These gears are liable to have worn teeth, or to have a tooth that breaks altogether. It’s most likely that you’ll have a tooth break on the pinion gear, which is the smaller gear of the differential, due to its size. When a break happens, you’ll hear clunking or clicking noises and experience poorer vehicle performance out on the road.
Bad Transfer Case
If you have a vehicle with multiple powered axles, then you’ll have a transfer case that transfers power to those axles from the transmission. This component is liable to leak or have a bad output shaft seal, which can create a clunking noise as you drive. A bad transfer case will most likely make noise as you accelerate or decelerate.
Your driveshaft and U-joints can break, bend, or become unbalanced, which will make your vehicle run very roughly. You’ll notice that your vehicle shakes quite a bit as it accelerates. You may have to replace your driveshaft if it is damaged.