A small differential leak may not immediately prevent the vehicle from moving, but continuing to lose lubricant can eventually leave gears and bearings without the protection they need. That can lead to increased heat, noise, wear and potentially much more extensive damage.
If you notice a differential leak, Certified Transmission in Bellevue can determine how serious it is and whether the fluid level has become low. If the vehicle is also making unusual noises or behaving differently, avoid unnecessary driving until the problem can be inspected.