Differential Fluid Change: What happens if you don’t change differential fluid? Differentials deal with moving parts that involve metal to metal contact that produces heat from friction. The said contact can also wear down its surfaces and eventually weakens its gears that can lead to failure.

Just use SAE 80 hypoid gear oil, any brand.

every 30,000 miles to 60,000 miles

Why is it important that I have it changed when recommended? Changing this oil is just as important as changing your engine’s oil, and for the same reason. Metal-to-metal contact wears down surfaces and creates heat from friction, which inevitably weakens the gears and leads to failure.

What are the Symptoms of Bad Differential/Gear Oil?

• Burning Smell from the Differential. When you notice a bad smell coming from your gearbox, you should take it as a sign of bad differential oil which can be contaminated hence not operating as it should be.
• Weird Noises.
• Vibrations.

So, once that gear fluid is gone or is dirty, it’s not going to be as effective. When that happens, it may be time to change it out. You’ll only pay somewhere between $80 and $140 for differential fluid change. The labor should be between $50 and $70, while parts can cost anywhere from $30 to $70.

Generally speaking, your Car ,just can’t run out of differential fluid . For that to happen you’ll have to go on driving for a long long time without any service of the vehicle ,which I’m sure no sensible motorist would do.

Over time, if the oil goes bad or you have a leak in your differential, metal will grind on metal and will wear down the surfaces. Since your differential/gear oil can go bad over time and needs to be replaced, you should be aware of the symptoms that indicate the oil needs to be changed.

Whining Sounds The most common sound of a failed differential is a whining noise. This is often due to poor lubrication within the differential, meaning there is a good chance that the differential fluid is leaking. If you spot a reddish fluid under the differential, there is certainly a leak.

There are two types of differential fluid. One is mineral oil, which is a natural, crude oil-based fluid. The other is synthetic differential fluid, which is created in a lab. As with all synthetic oils, synthetic differential fluid oils can be fine-tuned for optimal performance.

A typical rear differential repair costs anywhere between $200 and $400. These typical repairs would include your bearing, seals, and fluid changes. Of course, when a gear change is required, that’s when things get pricey. $1,500 is just the minimum you can expect to pay for new gears.

• Red Line MT-90 — Best Differential Fluid.
• Lucas Oil 10048 — Great for Synthetic Transmission and Differential.
• Red Line 75W90 — Gear Oil for Faster Shifting.
• Honda 08200-9003 — VTM-4 Differential Fluid.
• Mobil Delvac Syn Gear 75W90 — Fully Synthetic Differential Fluid.
• Royal Purple ROY01300 — High-Quality Synthetic Lube.

Synthetic 75W-90 Limited Slip Gear Oil utilizes the same synthetic oil technology as Driven’s 75W-140 Limited Slip Gear Oil to provide consistent limited slip differential performance.

If you add too much limited slip additive, you’ll notice your wheels will break loose super easy and you’ll get wheel-spin just making turns from a stop. If you make that mistake (like I did), just drain the oil and refill and you’ll be good.

Should I use a friction-modifier additive with AMSOIL synthetic gear lube? AMSOIL synthetic gear lubes are limited-slip capable and do not typically require an additional friction-modifier additive. However, depending on the differential’s friction material and degree of clutch wear, chatter can still sometimes occur.

The easiest way to tell if you have an open differential is to jack up the car and spin one of the rear tires. If the other wheel spins in the opposite direction, you have an open differential. If it spins in the same direction, you have a limited slip differential, or LSD.

Limited-slip differentials are considered a compromise between a standard differential and a locking differential because they operate more smoothly, and they do direct some extra torque to the wheel with the most traction compared to a standard differential, but they are not capable of 100% lockup.

The limited-slip differential is similar to the positraction differential, but allows the wheel with traction to have only a limited amount of greater power than the wheel that is slipping. A limited-slip differential will prevent the tire with less traction from separately spinning.