Differentials allow a vehicle to turn effectively, slowing the speed of the inside wheel and increasing the speed of the outside wheel to ensure smooth cornering. In order to keep the gears of the differential from overheating and breaking down due to friction, differential oil is sued to help preserve critical components. Differential work best when the gears of the differential are working together smoothly.
How this system works:
The differential redirects the power generated by the vehicle’s engine toward the wheels. The differential is also responsible for managing the rotational speed of the transmission and allowing the wheels to spin and different speed to allow for better cornering. A vehicle without a differential would have the wheels spinning at the same peed, forcing one to slip in order to corner. Front-wheel drive vehicles have one differential at the front of the vehicle and rear-wheel drive vehicles have one differential at the back of the vehicle. Many four-wheel drive vehicle have three differentials, one for each axle and one to modify the speed of the wheels between the front and back of the vehicle.
Common reasons for this to happen:
Old differential oil. Depending on the vehicle, differential oil should be changed every 30,000 to 50,000 miles. Old differential engine oil can pick up metal shavings which over time, could cause serious damage to the gears in the differential.
Water in the differential oil. While it is difficult to have water enter the differential, it is possible, especially in off-road vehicles that may travel through deep water. On top of the differential is a breather tube that allows hot gases to escape if necessary, cooling the differential. If the differential is submerged in water, the rapid temperature change may cause the breather tube to let water into the differential. This will contaminate the oil and if left unchecked will cause increased friction and may damage gears.
What to expect:
A top-rated mobile mechanic will come to your home or office to determine how your vehicle’s differential oil has been contaminated. The mechanic will then provide a detailed inspection report outlining the nature of the contamination and the cost of any repairs that need to be made.
How it's done:
When the mechanic arrives, he or she will raise the vehicle and inspect the differential for any leaks or superficial damage. In order to remove the contaminated oil, the mechanic must drain it from the differential.
If the mechanic suspects that the oil is old, he or she will drain the oil and inspect it to see if there are any metal filings that may have damaged the gears in the differential. Depending on the amount of metal shavings in the oil, the mechanic may want to inspect the gears for damage. The mechanic should then plug the differential and refill it will clean oil.
If the mechanic suspects that there may be water in the differential oil, he or she will begin by draining the contaminated oil. Oil with water in it typically looks gray and cloudy. The mechanic will then replace the contaminated oil with fresh oil. He or she may also drain some fresh oil again to make sure all of the water has been removed from the differential
In the case of all repairs, the mechanic will make sure that he or she replaces the contaminated oil with fresh oil before leaving. The mechanic should also start the vehicle and inspect the differential to ensure that there are no new leaks.
How important is this service?
Contaminated differential oil, if left unchanged can potentially cause more serious issues with the gears in the differential. Contaminated oil may contain metal shavings or water which will increase friction and may damage the teeth on the gears. If you notice and peculiar noises or sensations coming from the differential, you should stop driving the vehicle and have it inspected by a mechanic.