Changing differential oil is as important as changing the truck's engine oil. To keep your differential in optimum condition and to avoid costly repairs, it is best to follow the manufacturer’s recommendation on when to change the differential oil.
Most manufacturers recommend that the differential fluid be changed every 300 000 to 500 000 miles, depending on the type of vehicle and the driving conditions.
As it is with any other lubricating oil in your truck, the differential oil level needs to be checked occasionally, and the state and quality of that oil should be inspected. If your vehicle’s differential oil breaks down, the greater the wear and tear will be on your gears. If your truck has exceeded its gear oil service interval, or if you hear the differential whining, you may need to replace the differential/gear oil.
When the fluid gets dirty or contaminated it can put the components that it is meant to protect at risk of accelerated wear and even permanent damage. Usually bad or failing differential oil will produce a few symptoms that can alert the driver of a potential problem that should be serviced.
One of the symptoms that is most commonly associated with bad or failing differential oil is a noisy transmission or differential. If the gear oil runs low, or becomes excessively dirty, it can cause the gears to whine or howl as they turn.
The fluid in your truck’s differential will need to be replaced, if:
- the vehicle refuses to switch gears;
- the clutch becomes stuck or does not transition smoothly;
- the engine sounds like it is speeding up when your vehicle is maintaining a constant speed;
- the clutch petal becomes stuck to the floor;
- you hear knocking noises while driving in low speeds.
Ignoring any of these warning signs can have expensive aftereffects on your differential. Replacing differential fluid at regular intervals will prolong the lifespan of the vehicle.