The engine and transmission get a lot of attention when it comes to maintenance. But you shouldn't forget about your differential, especially since winter could have hidden problems with it.
If you own a rear-wheel drive car or a pickup truck, the differential is the ball-shaped thing in the middle of the underside of the car, between the rear wheels. It allows one wheel to spin a bit faster than the other, which needs to happen when the car makes a left or right turn.
The differential has gears inside of it and oil to keep them cool and lubricated. Like any other fluid, it dries up and gets dirty over time and needs to be replenished. If your differential oil is low, you might not notice it over the winter, as the cold will keep the temperatures down.
Diagram of differential function.
In the summer, though, low oil levels can destroy the differential. You'll know you're in trouble if you hear grinding coming from that area and even worse, if the wheels seem to slip or stutter for no apparent reason.
Maintaining the differential is easy. Just bring your car in for an oil change and it's one of the things we check out and fill if needed as part of our 27-point inspection. If you have any other problems with the differential, like worn seals or a leak, we can find that too.