Differential Fluid Service at our Haines City shop

The clearest sign is the color. Gear oil with water in it comes out milky and tan instead of clear amber or dark, and it often smells different too. If you launch a boat or cross water regularly, that's reason enough to have it checked rather than waiting for a noise.

It's an additive that lets the clutch packs in a limited slip differential engage smoothly. Some limited slip units require it, some gear oils already have it blended in, and open differentials don't need it at all. We check what your vehicle specifies before we fill it.

It depends on the axle. Some have a drain plug and some require removing the cover, and pulling the cover has a real advantage: we can see whether there's metal on the magnet or debris in the bottom. When your vehicle allows it, that look is worth having.

Yes, and it's in your owner's manual for your specific vehicle. Most manufacturers list one schedule for normal use and a shorter one for towing or severe service. We work from your manual rather than from a generic number, because the range across vehicles is wide.

Have it looked at. Unlike some fluids, fresh gear oil in a high mileage axle isn't a risky move, and what drains out tells us a great deal about the condition of the gears and bearings. Metal on the magnet is worth finding now rather than after a bearing lets go.