(Updated on December 31, 2019)
Differentials are what let the wheels of a vehicle rotate at varying speeds, especially when turning a corner. There are differentials in every vehicle on the road. Some car manufacturers place the differentials in the front and others place them in the back. The differentials may even be built into the front and rear ends.
Just like an engine, the differentials need lubricating fluid (oil) to keep running smoothly. The front and rear differentials typically use the same type of fluid, unless there is a transaxle built into the front differential.
In this case, the front differential will use totally synthetic oil while the rear differential will use a much thicker oil. Your local repair shop will be able to recommend the best oil for your differentials.
Differential Fluid Change Cost
The cost of replacing your differential fluid will be more expensive than changing your engine oil. When changing the front differential fluid, it will cost you anywhere from $70 to $130. This includes the estimated labor costs of around $40 to $60 and the estimated parts costs which are from $30 to $70.
As for changing the rear differential fluid, the estimated overall cost is a little more at a range of $80 to $150. This includes the labor costs between $50 and $70 and the parts costs of around $30 to $80. All these total prices are subjected to additional taxes and fees.
Read also: Pros and Cons of Limited Slip Differential
Differential Fluid Change Interval
The owner’s manual of your vehicle is the best place to learn the exact mileage that you need to travel before the front differential fluid should be changed. Most manufacturers will say to change the fluid at 25,000-mile intervals, while others may recommend 30,000-mile intervals.
If your front differential has a transaxle built into it, then you may even need to change the fluid every 20,000 miles. In this situation where there’s a transaxle involved, the transaxle will need to be replaced after you drain the old fluid and replace it with new fluid.
Since this is a very technical process, it is best to have a trained auto technician do this job for you.
Once again, the owner’s manual of your vehicle is the best place to find the appropriate interval for changing your rear differential fluid. Generally, most car manufacturers will recommend the fluid get changed after at least 30,000 miles, but some may allow you to go up to 50,000 miles.
Unless you get maintenance done at the dealership where you bought your car, the mechanics are probably not going to tell you when the fluid needs to be changed. It will be up to you to keep track of how many miles you’ve gone since the fluid was last changed.
Things to Remember
If you’re going to go the cheap route and try to do the replacement job yourself in order to avoid the labor costs, be prepared to get your hands messy. You will need a large pan to catch the fluid or gear oil in after you drain it from the differential. Be sure to wear clothes that you won’t mind getting dirty either.
Once the fluid is drained into the pan, you should place it into a secured container and bring it to a quick lube place, auto repair shop, or hazardous materials disposal site so it can be discarded properly.
Like any other automotive fluid, differential oil should not just be drained onto the ground or the grass because that would be toxic to the environment.
Finally, be sure to clean the contaminants off the other housing components of the differentials. Install a new gasket too because the old one will be worn now.