Today’s vehicles need fluid to lubricate their many moving parts. Without it, metal on metal would create heat and friction that would cause premature wear and damage vital components. While motor oil protects the engine, differential oil (or gear oil) lubricates differentials and manual transmissions. When this liquid becomes contaminated, it can generate symptoms that mean a differential is in trouble. Here are the most common signs a differential needs service:
Slipping or Jerky Gears
Trouble shifting into gear is a tell-tale symptom the lubricant needs replacing. When oil levels get too low for the transmission to properly operate, it’s time to take the car in. Usually, the issue can be righted with new oil, but a jerky transmission can also point to more complex problems. In fact, you might be able to avoid the mechanic simply by topping off oil. If this doesn’t fix the problem, you might be looking at something more serious.
When too little lubrication causes metal to hit metal, you usually hear about it in the form of whining or howling sounds. In addition, the sound tends to increase with speed, so pay attention to what your car is trying to tell you.
Another thing that happens with increased friction is the smell of hot metal. A combination of old, dirty oil and scorching metal, it will smell like the bottom of a filthy oven. Although this smell might indicate another issue, including an oil leak or overheated gear box, a lubrication lack is usually the culprit. Again, you can try topping it off to see if the smell subsides and if not, you should take the car in for service.
If you’ve missed a mileage point for differential service, this should tell you it’s time to go in. Neglecting regular maintenance is a dangerous habit and can lead to expensive, inconvenient repairs. Unfortunately, it’s easy to forget about differential oil since replacement is needed less frequently than other lubricants.
If you want your vehicle to last and its systems to perform, you will prioritize regular maintenance. Make sure to look to your owner’s manual for recommendations and stay ahead of all recommended services (small and large). If you have any questions or need advice about service, speak to a trusted mechanic who understands your model, driving environment and habits.