If you suspect you’re having differential problems, checking the fluid is the first step to take. If you see oil droplets on the ground underneath the axle of your car, it’s a good time to take a look at the differential housing. If you see oil dripping from the bottom of the housing, it’s a clear leak. Sometimes slow leaks won’t drip but will seep slowly, and you’ll find just a small wet spot on the bottom of the differential housing.