The rear differential is a critical part of a car as it is the component that transmits torque in the crankshaft before it gets to the transmission, drive shaft and finally the wheels. The rear differential enables the wheels to rotate at varying speeds, an aspect that's integral in maintaining the vehicle's stability on the road. If the diff is faulty, it can cause damage to other parts of the vehicle's driving system. It is paramount that you look out for the following signs which indicate that your car's diff is defective.
One of the signs associated with a faulty or failing differential is a noisy transmission. This is where the gears start to whine, grind or howl as they turn, especially when you accelerate or brake rapidly. The noise is usually a sign that the gear oil is low, dirty or contaminated. The gear oil is one of the many lubrication fluids used in a vehicle, but it is often forgotten since it is not serviced as regularly as the others. Have the gear oil changed or topped up immediately if you notice the howling sounds in the differential.
Vibrations in the vehicle
If the drive shaft universal joints in the vehicle are worn or damaged, they may cause vibrations through the transmission. You may notice these vibrations in the body or through the floor of the car when driving at a high speed or when accelerating. Note that vibrations in the vehicle can be a sign of other problems with the transmission system as well.
To ascertain that the problem results from the diff, you should look out for oil leaks as well. This is because the rear diff and universal joints have seals which can cause vibrations and differential failure when they crack. Broken seals allow gear oil to leak and you can notice the pooled fluid at the vehicle's rear when you park it for an extended period.
Rattling noise when starting the car
When a car is turned on and first put into drive, there should be no unusual noises. However, if you notice a rattling or cranking sound from the rear of the vehicle, it may be an indication that the universal joints are faulty. These drive shaft universal joints connect the transmission to the rear differential. When they are worn, they can affect the performance of the diff by forcing it to work harder. This wears down the gears of the rear diff and causes the clanking sound that you hear.
Contact a shop like Precision Automatic Transmissions if you need help. Avoid DIY repairs as the procedures involved in the repairs require specialised equipment that you may not have access to.