If your car, truck, or SUV has an all-wheel drivetrain, then you have probably been asked if you want to "service your differential" at least once when getting the oil changed. And while that question might seem like a ploy get you to buy more stuff from the dealership or shop where you get your car worked on, it's actually non. But is it really necessary to modify your car'due south differential fluid?

What is a differential?

When driving your car through a turn, or corner, the within bulldoze wheel – closest to the inside of the corner – travels less than the outside bicycle does. If the wheels were spinning at the same speed, then the car would hands fishtail around the corner, just having a differential in betwixt the two drive wheels prevents the motorcar from doing that as it allows the wheels to move independently.

Inside the differential is a cluster of gears that spin the wheels independently, even so, these gears need lubrication in order to move more freely and not heat up too much due to the abiding friction, hence the need for differential fluid in the housing. If this fluid isn't changed in the manufacturer-prescribed intervals, and then it can go dingy and thick, which could impairment the differential over time. Trust us, yous don't want to pay for a new differential.

Eaton Suretrac limited-slip differential cutaway
Eaton Suretrac limited-slip differential cutaway | Eaton

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How frequently do you need to replace the differential fluid?

Most manufacturer maintenance schedules require the differential fluid to be changed every 30,000 to sixty,000 miles, however, it tin differ betwixt vehicles. The chore itself is actually pretty piece of cake, nevertheless, if y'all're planning to change your vehicle's differential fluid at dwelling house, then information technology can go messy.

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How do modify a vehicle's differential fluid?

Irresolute the fluid in a differential is almost as easy as irresolute the oil in the engine. However, the process tin can differ between vehicles since some differentials only accept two plugs — one for filling the fluid and another for draining it – while other vehicles require you to remove the housing cover. Here is a simple layout of the process:

  • Lift the vehicle with a jack and identify information technology on jack stands
  • Locate the forepart or rear differential and its corresponding fill and drain plugs
  • Remove the fill plug showtime to ensure that it'southward not seized on there
  • Carefully remove the drain plug and drain the fluid into a pan
  • Supersede the drain plug
  • Fill the differential housing with fluid via a hose or pump until fluid pours out of the fill pigsty
  • Supersede the fill plug

For cars and trucks that require you to remove the entire differential housing embrace, the process is the same, but you'll need to remove more bolts to bleed the fluid. Be sure to apply the proper fluid that is mentioned in your machine'southward owner's manual.

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Yous can also have it professionally done

If you don't have space or the tools to alter your vehicle's differential fluid, then you tin have information technology done by your local mechanic or dealership. Nosotros propose shopping effectually for pricing since it's a unproblematic job and some shops exercise like to charge a lot for it. Either fashion, changing the differential fluid in your car is very important, and so yous can residual bodacious that your mechanic is not trying to run up your maintenance beak.