Leaks are a common feature of many car problems as lubricating fluids are required to keep most of the moving parts in working condition. One of the most vital parts of automobile assembly is the rear differential and it needs lubrication for smooth working. If you are experiencing noise, then the most likely reason is a lowering of lubricant levels.
About Rear Differentials
The driving force which takes your car forward emanates from the engine, that generates torque through fuel combustion. This torque is then transmitted via the crankshaft to the drive shaft and finally to the wheels, through the transmission and rear differential. It is a gear system placed at the back of rear-drive cars, that controls the torque transmitted from the engine to the wheels.
Wheel speeds need to vary when the car takes a turn. The wheel on the turning side must revolve slower than the other one. This speed control is made possible by the rear differential. Its primary types include locking and limited slip differentials. The differential is identified by its pumpkin shape and it is situated between the wheels, while being connected with both wheel axles. It is filled with a petroleum-based lubricating fluid that ensures its smooth working and saves it from the ravages of friction and heat.
When a fluid leak occurs, noise and friction set in, eventually leading to a damaged rear differential. To prevent the escalation of this situation, it's best that you check the differential pumpkin for leaks and replace the fluid immediately.
Since the differential is located on the car underside, you will have to get down under to check for leaks. Get a torch and bring out your jacks as you will have to raise the car to get a proper look. Get your car wrench set, as you'll need it. Get a can of rear differential fluid, in case you have to replace it, along with an oil filling pump. You will also need a drain pan to collect the leaking oil, in case you open up the system. Don't begin this car repair job, until you are equipped with the requisite tools.
Using the jack and stands, hoist the car above ground level, from the rear end. After making sure that it's stably raised, you can get under it with your torch. Locate the pumpkin body of the differential and check for leaked oil.
Locate its fill bolt and drain bolt. The leak may have been due to a loosening of the drain bolt. To replace fluid, open the drain bolt using an appropriate size wrench. Let the fluid be completely evacuated into the oil pan before you proceed.
Once the oil is completely drained, fix the drain bolt back again. Next, remove the fill bolt using a wrench and pump in the replacement fluid until its level reaches the fill bolt hole. Once that level is reached, fix the fill bolt back again. Dispose the extracted oil and lower your car from the jack stands. In case you find this procedure difficult, let a professional mechanic handle the job for you.
It is important that you refill the differential fluid as ignoring the task may result into major damage to the differential, along with large-scale repairs.